REVIEW | doi:10.20944/preprints201904.0140.v1
Subject: Chemistry And Materials Science, Theoretical Chemistry Keywords: waste cooking oils; plasticizers; syngas; volatile organic compounds
Online: 11 April 2019 (10:32:33 CEST)
The consideration toward Waste Cooking Oils (WCOs) is changing from hazardous waste to valuable raw material for industrial application. During the last five years some innovative processes based on the employment of recycled WCO have appeared in the literature. In the present review article, the most recent applications of recycled Waste Cooking Oil are reported and discussed. These include the production of bio-plasticizers, the application of chemicals derived from WCOs as energy vectors, and the use of WCOs as solvent for pollutant agents.
ARTICLE | doi:10.20944/preprints201703.0137.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: waste cooking oil; phthalic anhydride; copolymerization; microwaves
Online: 17 March 2017 (07:36:52 CET)
Solvent free copolymerization of epoxides derived from fatty acid esters of waste cooking oil with phthalic anhydride using (salen)CrIII Cl as catalyst and n-Bu4NCl/DMAP as co-catalyst was carried out for the first time under microwave irradiation, where reaction time was reduced from number of hours to minutes. The polyesters were obtained with molecular weight (Mw = 3084-6740 g/mol) and dispersity values (D = 1.18-1.92), when (salen)CrIII Cl/n-Bu4NCl was used as catalysts. While in case of DMAP as a co-catalyst, polyesters with improved molecular weight (Mw = 5537-6925 g/mol) and narrow dispersity values (D = 1.07-1.28) were obtained even at reduced concentrations of (salen)CrIII Cl and DMAP. The obtained products were characterized and evaluated by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) Techniques.
Subject: Chemistry And Materials Science, Food Chemistry Keywords: waste cooking oil; volatiles; 1H NMR; mass spectrometry; prototype
Online: 16 April 2019 (11:19:15 CEST)
Samples of sunflower Waste Cooking Oils (WCOs) subjected to several cycles of frying were treated with water under four different combinations of temperature and pH. The variation of the chemical composition of the oil samples was monitored through headspace Solid-Phase Microextraction (HS-SPME) coupled with gas-chromatographic technique (GC), 1H NMR spectroscopy and ESI+ mass spectrometry measurements. The possibility to modify the chemical composition of the recycled vegetable oil by tuning the water treatment parameters was exploited for the designing of a mini-plant for the production of bio-lubricants. A full description of the proposed prototype is also reported.
Subject: Environmental And Earth Sciences, Environmental Science Keywords: biofuel; biodiesel; hydrotreating; hydrocarbon; waste
Online: 21 March 2019 (10:00:50 CET)
Biofuels have become an integral part of everyday life in modern society. Bioethanol and fatty acid methyl esters are a common part of both the production of gasoline and diesel fuels. Also, pressure on replacing fossil fuels with bio-components is constantly growing. Waste vegetable fats can be replacing biodiesel. HVO seems to be a better alternative. This fuel has a higher oxidation stability for storage purposes, a lower temperature of loss of filterability for the winter time, a lower boiling point for cold starts and other. Viscosity, density, cold filter plugging point of fuel blend, and flash point were measured to confirm that a fuel from HVO is so close to a fuel standard that it is possible to use it in engines without modification. The objective of this article is to show the properties of different fuels with and without HVO admixtures and to prove the suitability of using HVO compared to FAME. HVO can also be prepared from waste materials and no major modifications of existing refinery facilities are required. No technology in either investment or engine adaptation of fuel oils is needed in fuel processing.
COMMUNICATION | doi:10.20944/preprints202003.0143.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: shrimp waste; astaxanthin; omega-3; limonene; bioeconomy
Online: 8 March 2020 (16:54:24 CET)
A shrimp oil rich in omega-3 lipids and carotenoids is obtained in remarkably high 5 wt% yield extending to pink shrimp processing waste (head and carapace) the circular economy approach to extract fish oil from fish processing by-products using d-limonene. Biobased limonene, a powerful antimicrobial and antioxidant agent, is an excellent solvent for both lipids and astaxanthin-based carotenoids preventing oxidative degradation during the extraction cycle including solvent and oil separation at 85°C. A new low cost route is established to extract valued marine oil from biowaste annually made available in over 2.2 million tonnes.
ARTICLE | doi:10.20944/preprints202310.0936.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: waste PET; recycle; water/oil separation; high value reuse
Online: 16 October 2023 (10:59:18 CEST)
As one of the important wastes, waste PET pollutes human living and natural environment seriously. PET is an important solid waste that needs to be recycled at present. The complete degradation of PET was realized at low temperature. The lipophilic hydrophobic membrane was formed on the surface of stainless steel mesh (SSM) by a simple dip coating method, and the oil-water separation material was successfully prepared. Due to the load of degradation products, the surface roughness of SSM increased from 19.09 μm increased to 62.33 μm. The surface changed from hydrophilic to hydrophobic, and the water contact angle increased to 123o. The oil-water separation flux of modified SSM is 9825 L/(m2·h) and the separation efficiency is 98.99%. The modified SSM has good reuse performance. This hydrophobic modification method can also be used to modify other porous substrates, such as activated carbon, filter paper, foam, and other materials. In this study, the porous substrate modified by the degradation product of waste PET was used to prepare oil-water separation materials, which not only solved the problem of white pollution, but also reduced the dependence on non renewable resources in the conventional preparation methods of oil-water separation materials. The research provided new raw materials and methods for the industrial production of oil-water separation materials, and had important application prospects.
ARTICLE | doi:10.20944/preprints201906.0132.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: scale; by-product; economical method; environment friendly; zero waste
Online: 14 June 2019 (10:09:59 CEST)
Mill scale is the by-product of iron and steel industry. It can be recycled via sinter plant or solid as sinter feed materials. 85 to 90% of the constituent particles are more than 0.008 inches. The iron content is near around 70 %, with a very small amount of alkaline compounds and non-ferrous metals. Mill scale is polluted and contaminated with lubricants, oils and greases from the equipment. In this experiment for recovering of oil from mill scale, it is treated with three different methods. Then all methods were compared according to the ability of oil elimination and iron recovered. After washing and boiling with surfactants, large amount of polluted waste water becomes a problem for environment so this wastewater was utilized for making of Microbial Fuel Cells (MFCs), production of electricity in MFC depends on the biodegradation of organic materials, so different waste were added in wastewater for making MFC. The remaining of MFC was converted in bioethanol, biodiesel and biofertilizer. So this research is economical and environmentally friendly and fulfilled the important aspect of green environment with zero waste. It will be a mile stone in the research of metallurgy, environmental engineering, recycling technology and zero waste management.
ARTICLE | doi:10.20944/preprints202306.1747.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: waste management; pest control; biopesticides
Online: 26 June 2023 (05:24:11 CEST)
Nano-emulsions of essential oils (EO) and their chemical constituents are promising raw materials for the ecological control of Tribolium castaneum. Curcuma longa Linn is a plant known for the properties of its rhizome which is used in food, health and hygiene products. Its leaves are by-products with no commercial value, but with unexplored bioactive volatile constituents. This study aims to evaluate the repellency of nano-emulsions containing the EO from leaves of C. longa or its three main chemical constituents against T. castaneum. The representative mixture of EO extracted in four different months showed p-cymene (26.0%), 1,8-cineole (15.1%) and terpinolene (15.5%) as major compounds. Nano-emulsions of EO (HLB 16.7), terpinolene (HLB 15.0), 1,8-cineole (HLB15.0) and p-cymene (HLB 15.0) were repellent at concentrations of 11 μg/cm2 (EO, terpinolene and p-cymene) and 1.1 μg/cm2 (1,8-cineole). The EO nano-emulsion droplet size increased linearly over time, remaining below 300 nm for 35 days and below 600 nm for 80 days. The EO nano-emulsion proved to be a green alternative to synthetic pesticides, as it was safe against the bioindicator Chlorella vulgaris. Terpinolene, 1,8-cineol and p-cymene were able to inhibit the enzyme telomerase from T. castaneum in an in silico assay, which may explain the repellency of these samples. This study provides ideas for the utilization of EO from leaves of C. longa as raw material of new environmentally friendly plant-derived nanobiopesticides.
ARTICLE | doi:10.20944/preprints202102.0142.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Anaerobic digestion; circular economy; biogas; fish waste; anchovy; limonene
Online: 4 February 2021 (15:03:46 CET)
Anchovies are amid the largest fish catch worldwide. The anchovy fillet industry generates a huge amount of biowaste (e.g. fish heads, bones, tails) that can be used for the extraction of several potentially valuable bioproducts including omega-3 lipids. Following the extraction of valued fish oil rich in omega-3, vitamin D3 and zeaxanthin from anchovy fillet leftovers using biobased limonene in a fully circular process, the solid residue was used as starting substrate for the production of biogas by anaerobic digestion. The results first reported in this study demonstrate good potential energy recovery of the anchovy sludge of about 280 mLCH4∙gVS-1. Due to unbalanced C/N ratio typical of marine biowaste, co-digestion with a carbon rich substrate is recommended.
ARTICLE | doi:10.20944/preprints201904.0020.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: Hydrotreating, mesoporous sulfide materials, waste Jatropha biomass, drop-in biofuels, upgrading technology
Online: 1 April 2019 (13:51:53 CEST)
The bio-oil was largely produced by thermal pyrolysis of Jatropha-derived biomass wastes (denoted as Jatropha bio-oil) using a Pilot Plant with a capacity of 20 kg h-1 at Thailand Institute of Scientific and Technological Research (TISTR), Thailand. Jatropha bio-oil is an unconventional type of bio-oil, which is mostly composed of fatty acids, fatty acid methyl esters, fatty acid amides and derivatives, and consequently it contained large amounts of heteroatoms (oxygen ~ 20 wt.%, nitrogen ~ 5 wt.%, sulfur ~ 1000 ppm.). The heteroatoms, nitrogen especially, are highly poisonous to the metal or sulfide catalysts for upgrading of Jatropha bio-oil. To overcome this technical problem, we reported a stepwise strategy for hydrotreating of 100 wt% Jatropha bio-oil over mesoporous sulfide catalysts of CoMo/γ-Al2O3 and NiMo/γ-Al2O3 to produce drop-in transport fuels, such as gasoline- and diesel-like fuels. This study is very different from our recent work on co-processing of Jatropha bio-oil (ca. 10 wt%) with petroleum distillates to produce a hydrotreated oil as a diesel-like fuel (Chen et al., Catalysts 2018, 8, 59; http://dx.doi.org/10.3390/catal8020059). Jatropha bio-oil was pre-treated through a slurry-type high pressure reactor under severe condition, resulting in a pre-treated Jatropha bio-oil with relatively low amounts of heteroatoms (oxygen < 20 wt.%, nitrogen < 2 wt.%, sulfur < 500 ppm.). The light and middle distillates of pre-hydrotreated Jatropha bio oil was then separated by distillation at temperature below 240 oC, and the temperature of 240-360 oC. Deep hydrotreating of light distillates over sulfide CoMo/γ-Al2O3 catalyst was performed on a batch-type high pressure reactor at 350 oC and 7 MPa of H2 gas for 5 h. The hydrotreated oil was a gasoline-like fuel, which contained 29.5 vol.% of n-paraffins, 14.4 vol.% of iso-paraffins, 4.5 vol.% of olefins, 21.4 vol. % of naphthene compounds and 29.6 wt.% of aromatic compounds, and little amounts of heteroatoms (nearly no oxygen and sulfur, and less than 50 ppm of nitrogen), corresponding to an octane number of 44, and it would be suitable for blending with petro-gasoline. The hydrotreating of middle distillates over sulfide NiMo/γ-Al2O3 catalyst using the same reaction condition produced a hydrotreating oil with diesel-like composition, low amounts of heteroatoms (no oxygen and less than 50 ppm of sulfur and nitrogen), and a cetane number of 60, which would be suitable for use in drop-in diesel fuel.
ARTICLE | doi:10.20944/preprints201812.0353.v1
Subject: Engineering, Energy And Fuel Technology Keywords: agroindustrial waste; alperujo and orujo; rotary dryer emissions; volatile organic compounds; biomass drying
Online: 29 December 2018 (02:39:58 CET)
In the industrial production of olive oil, both solid wastes and those produced from their incineration are a serious environmental problem since only 20% w/w of the fruit becomes oil and the rest is waste, mainly orujo and alperujo. A key aspect to transform these wastes into an important source of energy such as pellets is to recognize the most appropriate time of the year for waste drying, with the objective of minimizing the environmental impact of the volatile compounds contained in the waste. In this work, the emissions produced during thermal-mechanical drying were studied along a period of six months of waste storage in which alperujo and orujo were stored in open containers under uncontrolled environmental conditions. The studied emissions were produced when both wastes were dried in a pilot rotary drying trommel at 450ºC to reduce their initial humidity of around 70-80% w/w to 10-15% w/w. Results indicated that when the storage time of the wastes in uncontrolled environments increases, the emission of odorant compounds during drying also increases as a consequence of the biological and chemical processes occurring in the containers during waste storage. The main odorant VOCs were quantified monthly for six months at the outlet of the drying trommel. It was determined that the drying of this type of waste can be carried out properly until the third month of storage. Afterwards, the concentration of most VOCs produced widely exceeded the odor thresholds of selected compounds.
REVIEW | doi:10.20944/preprints202307.1813.v1
Subject: Engineering, Aerospace Engineering Keywords: UAV; aircraft airframe; agricultural waste; natural fiber composites; waste composites; pineapple; reusing waste; natural waste
Online: 26 July 2023 (13:26:44 CEST)
In the past few decades, the use of agricultural waste has been increasing due to the increasing demand for sustainable materials. This paper aims to review the significance of agricultural waste as a type of wealth and its potential as an alternative material in the composite field. It was found that many agricultural wastes had been utilized in various production of ecological products. The review discusses the physical, mechanical, and chemical properties of the natural fibers made from agricultural waste and the use of Pineapple Leaf Fiber Reinforced Composite to manufacture UAVs (Unmanned Aerial Vehicles). The extracted waste fibers’ physical, mechanical, and chemical properties show that these agricultural wastes can produce better advanced composite materials suitable for structural applications. The use of pineapple leaf fiber in Unmanned Aerial Vehicles manufacturing has the potential to revolutionize this industry and contribute to a more sustainable future.
ARTICLE | doi:10.20944/preprints202306.2092.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Electronic waste; Waste management; Copper recovery
Online: 29 June 2023 (10:13:34 CEST)
The exponential growth in the consumption of electronics, in combination with the reduction in their useful life, leads to a significant increase in the volume of electronic material discarded. Printed Circuit Boards (PCBs) are modules composed of ceramic, polymer and metallic materials of high economic value and with a great potential for damage to biotic and anthropic environments when inadequately discarded. The aims of this work was to study the main environmental impacts and the efficiency of mechanical operations in the electronic waste recycling process in optimizing the concentration of metallic copper. For this, the samples obtained were characterized according to their morphology and chemical composition, and subjected to physical and mechanical treatments: dismantling, grinding, separation by granulometry, density and magnetic property. The environment impacts were estimated by the Life Cycle Assessment of the pre-treatment processes, associated with copper extraction operations in WPCBs. According to the results obtained, it is possible to infer that the NM +1mm Concentrated product presents in its metallic composition around 78% of copper, which contributes to the efficiency of the hydrometallurgical extraction processes. It is noteworthy that the Concentrated class represents about 14% of copper (wt) taking into account the amount of 3.789 kg of PCB waste input material. The potential for reinsertion of the dust in the material recovery process is highlighted, given that the chemical composition of this particulate has a significant presence of metals. In general, it was found that due to the higher concentration (wt %) of the sample being allocated in the range of - 0.15mm + 0.05mm, the elements Fe (18.30%), Si (10.73%), Ca (9.21%) and Cu (8.89%) stand out regarding the participation of the elemental composition of this fraction and also regarding the general composition of the sample. Furthermore, the generation of dust during the fragmentation process, can be associated with occupational respiratory diseases when not managed. About the Life Cycle Assessment, in seven of the nine categories evaluated, crushing and screening activities accounted for more than 90% of the recorded impact values. In general, it is estimated that in the pre-treatment phase be generated 15.4 kg CO2 eq.
ARTICLE | doi:10.20944/preprints202106.0670.v2
Subject: Engineering, Chemical Engineering Keywords: Household waste management; Recyclables; Healthcare waste; COVID-19
Online: 26 October 2023 (09:46:26 CEST)
Solid waste management is challenging in many countries, especially developing economies. The impacts of the pandemic continue to be felt and have indicated secondary impacts on waste management. This work draws on data on household solid waste (HSW), healthcare waste (HCW), and recyclables collected in the Rio de Janeiro municipality, analyzed from January 2018 to December 2022. As expected, the collection of HCW in Rio de Janeiro municipality experienced a noticeable increase in 2020 and 2021, with an average of 46.9 tons and 54.3 tons collected, respectively. Notably, 2021 saw a significant 30% increase compared to 2019 (p-value<0.001). No significant difference was observed in recyclables collected from 2018 to 2021. The average recyclable amount was 3,638 and 3,747 tons per month in 2020 and 2021. In contrast, the monthly amount was equal to 4,819.5 tons in 2022, representing an increase higher than 32% compared to previous years (p-value<0.05). Our findings can be used to adapt and improve waste systems to cope with similar emergency scenarios in the future, serving as a template for municipalities with similar challenges.
Subject: Engineering, Civil Engineering Keywords: waste management; civil construction waste; sustainability
Online: 27 October 2019 (10:26:32 CET)
Given the importance of the development of urban infrastructure and environmental impacts produced by the civil construction waste (CCW), it is important to correct the handling of CCW with objective solutions that are more environmentally friendly. In that sense the present study aimed to determine indicators that make it possible to estimate the amount of CCW generated from construction sites in the city of Londrina, Parana State, Brazil. The generation of CCW was estimated in a general way, regarding the composition of its mixture, correlated to the gross areas of the buildings studied and their generated volumes of RCC. This generating rate was evaluated in a general way and specifies two types of sites: the new residential and new non-residential constructions. The data required for the development of these indicators was obtained through extensive survey and interviews carried out at the environment secretariat of the City Hall. The generating rate of CCW obtained for non-residential buildings was 0.2052m3/m2 or 170.44kg/m2, for new residential sites was 0.2054m3/m2 or 170.60kg/m2 and for new commercial or non-residential construction sites, it was 0.20453 m3/m2 or 169.85kg/m2. It was also possible to estimate the amount generated annually per inhabitant in the municipality, which is 0.60m3/inhabit.year or 498.55kg/inhabit.year.
ARTICLE | doi:10.20944/preprints202304.0726.v1
Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: agricultural waste; bio-waste; synergies; web platform; bioeconomy; industrial symbiosis; waste management
Online: 21 April 2023 (13:48:17 CEST)
Sustainable bio-economy is considered to be one of the most promising routes towards the transition to a circular and climate-neutral economy. The valorization industry of bio-waste and agri-food by-products represents a key player in bioeconomy. In this article the design and the development of a web platform aiming at promoting synergies enabling the agricultural waste valorization is presented. The platform consists of: (i) the AgriPLaCE Waste Management Database which provides the users with an extended list of potential utilization measures for a variety of agricultural waste streams (ii) the AgriPLaCE Synergies Tool which aims to create synergies between different actors involved in the value chain from agricultural waste production to waste treatment and new valuable products’ exploitation. At the initial stage, the conceptual design of both tools took place by conducting an in-depth analysis for the user needs and services alongside the system architecture. Following, the AgriPLaCE platform development stage took place, with the implementation of all the necessary subsystems. The results showed that multiple potential collaborations can arise by the use of the AgriPLaCE platform, while users can also deepen on alternative and emerging treatment technologies and valuable products that can derive from a wide range of agricultural waste streams.
ARTICLE | doi:10.20944/preprints202007.0118.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: sustainable procurement; waste policy; C&D waste regulation; overregulation; recycled waste materials
Online: 7 July 2020 (08:41:48 CEST)
Increased construction activities in Australia have led to the generation of a massive volume of construction and demolition (C&D) waste annually. Management of this volume of waste requires an effective waste framework. The literature reported that the current Australian waste framework does not meet expectations and needs immediate improvements. This study was therefore conducted to seek the key C&D stakeholders' opinion about various issues identified in this waste stream. The specific objectives of this study are identification of the main barriers to effective C&D waste management, the impact of current regulations and opportunities to enhance the current C&D waste management system. A survey was conducted in 2019 to capture the stakeholders' perception. 132 participants from various industries and government agencies based in various Australian jurisdictions took part in the survey. The key results showed that the main barriers towards an effective management system are "overregulation, tough acceptance criteria, and increased testing requirements", "lack of local market" and "culture, poor education and low acceptance". Furthermore, a low number of participants indicated that the current legislation encourages waste recovery activities. The main areas of improvements included "providing a guideline that determines the accepted level of contamination for reusing C&D waste”, "preparation of guidelines on requirements of using recycled C&D materials in different industries" and "setting target for reduction, reusing, and recycling C&D waste". The results can inform policy development and be used as evidence for a broader discussion to solve lasting issues in C&D waste management.
ARTICLE | doi:10.20944/preprints201808.0106.v1
Subject: Engineering, Civil Engineering Keywords: Municipal Solid Waste; Waste Management, Sustainable Technology, Recycling, Reuse, Waste to wealth
Online: 6 August 2018 (09:44:57 CEST)
The practice of collecting, treating and management of solid waste prior to disposal has become a necessity in developing and modern societies. Over the years, it is known that most wastes that are disposed have a second hand value. However, the construction cost for conventional Material Recovery Facility(s) (MRFs) has been a major barrier for implementation. These technologies require considerable technical expertise, which is often not available in developing nations to successfully operate the MRFs. Covenant University; a private mission institution through her waste to wealth scheme is focused on managing and processing used materials to reusable products. These include Pet bottles, Paper wastes, Food wastes from cafeteria, plastic food packs, nylon, tin cans and others. Specific areas chosen for the Survey include the residential areas for staff and students and the two cafeterias. The waste generated was characterized based on the waste stream so as to quantify the amount of recyclable waste generated and most occurring. The survey involved the use of structured questionnaires, on-site observations and measurements. The study reveals an average amount of recyclable waste generated per day in the institution as 13.46% pet bottles, 4.03% paper, 55.56% food waste, 12.64% plastic, 9.63% nylon and 4.68% tin cans. The study established that adequate waste characterization is a requirement for effective integrated solid waste management which would boost resource recovery, reuse and recycling.
REVIEW | doi:10.20944/preprints202309.0757.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: solid waste; solid waste management; Navrongo; Karlshrue
Online: 12 September 2023 (11:07:16 CEST)
Effective solid waste management is crucial for protecting public health and the environment. Global concentration on finding sustainable methods of handling waste continue to top the list of most governmental-related project checklists. This paper provides a case study on the management of municipal solid waste in the cities of Karlsruhe, Germany and Navrongo, Ghana as developed and developing countries respectively. This study aimed at comparing and drawing lessons from how these two different cities manage their solid waste. The waste management system in Karlsruhe prioritizes waste separation, recycling, and a pay-as-you-throw system has led to an efficient and sustainable waste management system that minimizes waste and protects the environment. Karlshrue's adoption of a continual developmental plan structure focused on integrated WM concepts is credited with safeguarding the long-term viability of waste management in the city. In contrast, Navrongo's waste management system faces several challenges, including inadequate resources and infrastructure, traditional waste disposal practices, and the lack of well-planned waste management strategies. To improve effective solid waste management systems in Ghana, a collaborative approach involving the government, local organizations, and the community is necessary. This can include investing in infrastructure, implementing waste separation and recycling programs, and educating the public on the benefits of sustainable waste management practices. Learning from successful models like Karlsruhe can help accelerate the development of sustainable waste management practices in Ghana, and ultimately protect public health and the environment.
REVIEW | doi:10.20944/preprints202309.0384.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Solid Waste; Waste Management; Environment; Human Health
Online: 7 September 2023 (03:06:49 CEST)
Solid waste has become a tenacious issue worldwide. It has been increasing exponentially due to urbanization and the increase in the population. Since the twentieth-century technological revolution, there have been significant changes in the composition of solid waste. It poses significant challenges for waste management systems worldwide. Waste management is the process of handling waste right from its creation to its final disposal, including transport, collection, treatment, and monitoring. The present solid waste management (SWM) system is affected by unfavorable institutional, economic, technical, legislative, and operational constraints. Poor waste management is affecting ecosystems and human health, damaging our finite natural resources, impeding human economic progress, and harming people's quality of life. Now, researchers are concerned about the environment's degradation, a decline in quality of life, and risks related to waste management grow as the volume of solid waste. So, they are focusing on sustainable waste management practices which will be crucial for creating a cleaner and healthier environment for future generations. This chapter focuses on the concept of solid waste, its types, management, and its effect on the health of humans and the environment.
ARTICLE | doi:10.20944/preprints202309.0169.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: VOCs; kitchen waste; waste storage; compost biochar
Online: 4 September 2023 (10:58:43 CEST)
It is expected that due to the new UE regulation focus on waste management, managing kitchen waste will become more important in the future, especially in households. It is, therefore, crucial to develop user-friendly and odor-free containers to store kitchen waste. The study aimed to test the effectiveness of compost biochar in reducing noxious odors and volatile organic compounds (VOCs) released during kitchen waste storage. Varying quantities of compost biochar (0%, 1%, 5%, and 10%) were added to food waste samples and incubated for seven days at 20℃. VOCs released were analyzed on days 1, 3, and 7 of the storage simulation process. The results indicated that adding 5-10% of composts’ biochar to kitchen waste significantly reduced emissions in 70% of detected VOCs compounds. Additionally, Compost's biochar can be used to eliminate potential odor components and specific dangerous VOCs such as ethylbenzene, o-xylene, acetic acid, and naphthalene. A new composts’ biochar with a unique composition was particularly effective in reducing VOCs and could be an excellent solution for eliminating odors in kitchen waste con-tainers.
ARTICLE | doi:10.20944/preprints202003.0006.v1
Subject: Engineering, Civil Engineering Keywords: plastic waste; concrete waste; recycling; heat pressing
Online: 1 March 2020 (03:24:14 CET)
Demolished concrete and plastic waste are two increasingly aggravating problems. In this study, a novel method was proposed to simultaneously recycle concrete and plastic wastes by compacting concrete and plastic powders together under pressure and temperature. The influence of compression pressure and temperature as well as the mixture proportion on the bending strength of specimens was investigated. The results showed that pressure and temperature had a positive effect on the specimen strength; however, the molding temperature should not exceed the melting temperature of plastic. The proportion of plastic had a minimal effect on the bending strength of the specimen when plastic accounted for 25%–75% of the overall mass of the test piece.
ARTICLE | doi:10.20944/preprints202104.0012.v1
Subject: Engineering, Automotive Engineering Keywords: GIS in solid waste collection; waste vehicle routing; ArcGIS Network Analyst; waste bin allocation; municipal solid waste management
Online: 1 April 2021 (11:04:58 CEST)
Vehicle routing is a critical factor in municipal solid waste (MSW) collection planning and operations. Poor routing can introduce inefficiencies and cause targeted levels of services or performance to be missed irrespective of the level of resource application. Trial and error approaches have been proven to be not the best in the planning and prediction of expected performance. This study explores various Geographic Information System (GIS) tools and analysis techniques, and how they can be applied to optimizing vehicle routes in light of challenging site conditions. Using Adentan West residential area, suburb of Accra Ghana as a case study, current performance of the trial and error method was measured and a GIS computer model was used to evaluate various optimization scenarios to determine the level of savings that can be made. Field measurements were taking with Global Positioning System (GPS) devices for waste collection activities in areas with varying characteristics and conditions, and data analysed for one selected vehicle operating four days per week. It was found that, for a scenario where only the bin collection order was optimized while route selection was restricted by the ArcGIS Network Analyst, 2.6% of travel distance and 2.21% of travel time were saved. For the second scenario where only the route selection was optimized while order of bin collection was restricted, 4.1% and 1.5% of travel distance and time respectively were saved. For a third scenario where both the order of collection and route selection were together optimized, 10.9% and 3.7% of travel distance and time respectively were saved. Lastly, by regrouping all the bins for daily collection, 4.5% and 1.2% of travel distance and time respectively were saved. The results demonstrated that there is always room for optimization of solid waste collection routing irrespective of site constraints and other challenges that the nature of bin distribution pose to drivers. In developing countries like Ghana, where there is high demand for services in the face of limited road network access, application of GIS in optimization of routes will guide providers in planning and subsequently make more savings in fuel consumption, vehicle maintenance and cost of man-hours.
REVIEW | doi:10.20944/preprints202205.0074.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Household waste; household waste management; sustainable city; integrated waste management model; Malaysia cities
Online: 6 May 2022 (10:27:56 CEST)
In recent years, Malaysia has faced environmental challenges caused by municipal solid waste, especially household waste, during the Covid-19 pandemic. Among all the household waste, plastic and paper are the most prominent waste that causes environmental hazards. Several recycling associations in Malaysia have carried out their practices for better waste sustainability and management to curb the increasing amount of household waste. However, the effectiveness is still vague in achieving smart and effective household waste management. Therefore, this paper aims to investigate Malaysia’s household waste management, mainly in three significant municipalities in Malaysia for Kuala Lumpur, Penang and Melaka, in becoming a resilient and sustainable city by addressing two main research questions 1) What are the key factors for ensuring the more success move for future household waste management in cities? and 2) How will the 3 municipalities address their waste issues based on the key factors from RQ1, respectively? This paper reviewed 13 waste management articles and explores the potential of the four factors of waste management from the perspective of technology and data, economy, social and governance. The discussed factors and models contributed to an integrated future-proofing framework that focuses on smart waste tracking, an gamified awareness education, and strict policies to control waste management are the way forward for the future of smart cities household waste management.
ARTICLE | doi:10.20944/preprints201809.0087.v1
Subject: Engineering, Civil Engineering Keywords: solid waste management; environmental pollution; agricultural waste; cassava waste; biogas generation; sustainable technology
Online: 5 September 2018 (05:32:59 CEST)
Agricultural product like cassava produces huge amounts of waste when processed to consumable goods. The waste generated is generally considered to contribute largely to environmental pollution. This study therefore investigates the waste management practice that is adopted by cassava processors in Ogun State, Nigeria. Five (5) Local Government Areas (LGAs) dominant in processing cassava were selected for the study on the basis of spatial location distribution; landmass and population. The survey involved the use of structured questionnaires administered to cassava processors of the selected LGAs. The Statistical Package for Social Sciences (SPSS) software application and descriptive statistics were used for data analysis. Results of the analysis show that majority (70%) of the cassava processors are females. Cassava peel constitutes 10% of the waste produced, of which 91% are heaped at refuse dump in most communities. Results also reveal that 86.3% of cassava residues are used for animal feeds. Other findings show that the peels when dried are used as bio-fuel for cooking and there is a significant potential for biogas production. From the data captured from respondent during the study, most processors are willing to pay for an improved waste management system. The study therefore suggests proper waste management of cassava waste to minimize environmental pollution.
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Food waste index; Household food waste; Waste characterisation; Waste sorting analysis; Avoidable food waste; Preparation residues; SDG Target 12.3; Methodology development; Assessment of current situation
Online: 15 July 2021 (15:38:01 CEST)
Target 12.3 of the United Nations Sustainable Development Goals (SDGs) calls for halving per capita global food waste at the retail and consumer levels, by 2030. The Food Waste Index is suggested as a methodology for grasping the situation. This paper focuses on the consumer level (household food waste). We argue that in order for generating useful information for devising and implementing effective measures for reducing food waste, it should be measured at Level 3 of the Food Waste Index, based on sorting analysis of generated waste, making a distinction between avoidable and non-avoidable food waste. Furthermore, a breakdown by sub-categories that reflect the flow of food in the household could help identify target behaviours. We have developed a categorisation scheme that is internationally agreeable and adoptable, and 1) generates useful information for policy-making and for tackling with reduction of food waste, 2) makes clear the concept of avoidable food waste, and 3) is practical and does not overcomplicate the work of grasping the situation of food wastage. Results of workshops regarding this scheme suggest that the scheme satisfies the criteria. This scheme has been applied to a few sorting analyses of household food waste in Japan, and their results are compared.
ARTICLE | doi:10.20944/preprints202308.0503.v1
Subject: Business, Economics And Management, Business And Management Keywords: economic growth; environment; municipal waste; waste management; Bulgaria
Online: 7 August 2023 (10:47:59 CEST)
This paper examines the relationship between GDP per capita and waste generated in European Union countries, highlighting the importance of this relationship for understanding the environmental consequences of economic growth and formulating waste management policies. The analysis findings demonstrate that, in most cases, higher GDP is associated with higher amounts of waste, although there are exceptions to this trend. A smaller number of countries are also found where no such relationship exists. These are primarily high-income countries in the lower part of the EKC or countries in transition. Cluster analysis reveals regional differences in the relationship between GDP and waste that the economic factors and the level of development in the regions concerned can explain. Bulgaria is among the European countries with the lowest economic growth associated with a large amount of waste. The analysis, therefore, focuses on Bulgaria. The impact of GDP per capita, Human Development Index and Population Density on municipal waste in Bulgaria is studied. The aim is to identify significant relationships and dependencies between these factors and the amount of waste. Based on the results of multiple regression analysis and the findings from municipal waste management data in Bulgaria, specific actions are proposed for municipal waste management in the country. Recommendations are made for developing sustainable waste management policies and sharing best practices between regions.
REVIEW | doi:10.20944/preprints202307.0264.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Jackfruit waste; Zero waste; Bioconversion; Bioenergy; Phenolic; Biochemical
Online: 5 July 2023 (04:47:43 CEST)
Valorization of food and fruit wastes has the potential for the production of sustainable energy and biochemicals. Approximately 70% of the weight of the original jackfruit (Artocarpus heterophyllus L.) fruit is lost during processing as waste in the form of peeled skin and core, both of which have not been utilized and, thus contribute to disposal as well as pollution issues. The major components, cellulose, and hemicellulose, can be biologically transformed easily into bioenergy sources like ethanol, methanol, and butanol; valuable phenolics and biotechnological products like pectin, citric acid, bromelain, ferulic acid, and vanillin; and many other products. These residues can also be utilized as essential sources for the biological transformation process leading to the production of numerous products with added value, such as phenolic antioxidants, phenolic flavor compounds, and organic acids. Thus, the value addition of jackfruit waste can support the sustainable solution towards food and nutritional security. In this way, zero waste can be achieved through novel biorefineries which are critically highlighted in this paper. Furthermore, novel technologies for the conversion of jackfruit wastes are summarized with recent findings.
ARTICLE | doi:10.20944/preprints202304.0066.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Waste Classification, Deep Learning, Waste Management, Computer Vision
Online: 5 April 2023 (15:25:05 CEST)
Computer vision methods have shown to be effective in classifying garbage into recycling categories for waste processing, existing methods are costly, imprecise, and unclear. To tackle this issue, we introduce MWaste, a mobile application that uses computer vision and deep learning techniques to classify waste materials as trash, plastic, paper, metal, glass or cardboard. Its effectiveness was tested on various neural network architectures and real world images, achieving an average precision of 92% on the test set. This app can help combat climate change by enabling efficient waste processing and reducing the generation of greenhouse gases caused by incorrect waste disposal.
REVIEW | doi:10.20944/preprints202210.0476.v1
Subject: Social Sciences, Sociology Keywords: COVID-19; Waste management; Recycling; Sustainability; Waste shock
Online: 31 October 2022 (09:54:27 CET)
Recycling and waste management have garnered immense popularity in recent years, but few studies have been carried out regarding these systems. Therefore, an in-depth literature review was done in order to highlight the different sectors of the recycling system that need to be reformed. Hence this study examined recycling and waste management systems within three categories–medical, municipal, and plastic–that were carried out pre and post COVID by reviewing previous studies, technical reports, and annual reports. This was done by visiting numerous academic search engines alongside online resources that were utilized to assemble literature related to waste and recycling systems. Continuing a recurring idea was that no matter the type of waste, further research regarding all waste should be carried out. Additionally, since recycling and waste management are a vital part of our society, and seeing how unpredictable events such as the pandemic may be, it is paramount that that research is done not only on how the pandemic has affected systems now, but also how we can learn from current issues to utilize them for future “waste shocks”.
ARTICLE | doi:10.20944/preprints202011.0190.v1
Subject: Engineering, Automotive Engineering Keywords: zero waste; plastic waste; circular economy; recycling performance
Online: 4 November 2020 (10:45:14 CET)
Despite the increase in popularity of Zero Waste (ZW) concept, the successful implementation of this concept in waste management is still facing many challenges. The plastic recycling rate in Australia is currently only about 9.4%, which could leave up to 90.6% of plastic consumption being sent to landfills. The state of Victoria (in Australia) has proposed an ambitious plan to upgrade its waste and recycling system and to divert about 80% of waste from landfills by 2030. The aim of this research is to study Victoria’s current waste management plan and to develop a simulation model to assess the feasibility of it achieving zero plastic waste by 2035. In this direction, a fundamental knowledge of global ZW implementation needs to be acquired in order to understand the challenges, obstacles, and uncertainties in achieving ZW target. A simulation model is established using a method called double baselines. This method was developed as an improvisation to address the limitation of data availability for the model development. The model will run on 4 scenarios including one from Victoria’s current plan. Outcomes from the model are produced in comparative charts covering 6 key considerations including the rates of plastic consumption, waste to landfill, diversion, recycling, relative accumulative cost and effort. The findings of this study pointed out that Victoria’s current plan are feasible for its goal and presented with opportunities for improvement especially towards zero plastic waste. Besides, study results also reveal that the Victoria’s current plan to achieve 80% diversion rate by 2030 is possible but the zero plastic waste target by 2035 is less likely to happen.
ARTICLE | doi:10.20944/preprints202309.1549.v1
Subject: Chemistry And Materials Science, Ceramics And Composites Keywords: waste recycling; brick waste; geopolymers; tuff waste; alkali activation; historical buildings restoration; circular materials
Online: 22 September 2023 (10:22:52 CEST)
Nowadays the preservation and restoration of historical building needs to be faced in accordance with a novel sensibility regarding environment to preserve the future generations. In this context, the scientific community is focusing on novel and sustainable materials and techniques allowing durability and mechanical performances and at the same time compatibility with the existing heritage. Alkali activated materials represent a great challenge to produce new materials starting from the existing ones with reducing consumption, emission of greenhouse gases and environmental impact. This study deals with the valorization of waste materials coming from demolition and construction activities in the manufacture of geocomposites suitable for restoration and conservation of historical heritage. In particular, waste from tuff sawing and brick grinding were used as raw materials, then the geopolymeric samples produced were characterized from physical-chemical and mechanical point of view in order to investigate their performance and evaluate their suitability as materials for historical buildings recovery. Brick waste based geocomposites resulted to be more compact than the tuff-based ones as showed by the higher density values and the lower values of open porosity and water absorption and as further confirmed by the trend of the mechanical performance. Moreover, experimental data showed that physical and mechanical properties of both bricks and tuff waste-based geocomposites, even with different waste content, are compatible with existing building materials and to all the traditional repairing products.
ARTICLE | doi:10.20944/preprints202307.1727.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Governance Assessment Tool (GAT); waste management; community-based solid waste management (CBSWM); waste bank
Online: 26 July 2023 (03:26:42 CEST)
Indonesia's government anticipates waste problems by managing them through a large number of waste reduction programs. From a governance perspective in Indonesia, it is known that actors from diverse governmental levels and across sectors are involved in waste management, and their involvement largely depends on their institutional goals and problems. Hence, they are expected to coherently collaborate together by developing and implementing sustainable instruments and resources for improving waste management problems. However, it is necessary to understand how supportive and restrictive the governance of waste reduction programs is to encourage successful trash reduction. This study is designed to evaluate and examine the application of Community-Based Solid Waste Management (CBSWM) in Makassar. In this research, The Governance Assessment Tool (GAT) was applied to analyze the governance context of the waste reduction programs in Makassar qualitatively. From the assessment, contexts can be described as either supportive or restrictive of the processes of implementing public policies on waste management. As a result of such an assessment, this study shed light on some opportunities to improve the governance of waste management implementation's impact on reducing waste in Makassar, South Sulawesi, Indonesia. The conclusion of this study depicts that the most important actors are affiliated with the local government and the community. Moreover, this study shows that the assessment of contextual governance is predominantly restrictive.
ARTICLE | doi:10.20944/preprints202207.0277.v1
Subject: Engineering, Energy And Fuel Technology Keywords: organic waste; waste to energy; waste to carbon; solid fuel; hydrochar; temperature; hydrothermal treatment
Online: 19 July 2022 (05:21:12 CEST)
Economic development and population growth lead to increased production of chicken manure (CM), which is a problematic organic waste for its amount, environmental threats, and moisture content. There are different ways of CM, namely anaerobic digestion, composting, combustion, and direct land spreading. Hydrothermal carbonization (HTC) is another emerging way, however. In this study, the HTC of CM was performed to produce energy-rich material called hydrochar (HC). The effects of HTC temperature (180, 240, 300 C) and process time (30, 90, 180 min) were summarized. Proximate and ultimate analysis, as well as heating values (HHV, LHV), have been performed both on raw CM and derived HC. Additionally, the process performance has been examined. The obtained results show that HTC is a feasible method for CM disposal and valorization. Although process time did not influence considerably fuel properties of CM, higher temperature led to significantly higher HHV, reaching 23,880.6734.56 Jg-1 at 300 C and 180 min with an improvement of 8,329 Jg-1 compared with raw CM (15,551.67 Jg-1). The process conducted at 240 C in 30 min has been specified as the most favorable, due to the highest energy gain of HC and relatively low energy consumption.
ARTICLE | doi:10.20944/preprints202305.1824.v1
Subject: Engineering, Energy And Fuel Technology Keywords: waste combustion; grate combustion; fluidized bed combustion; energy from waste; desalination from waste; district cooling from waste; multi criteria decision analysis
Online: 26 May 2023 (03:16:45 CEST)
Liability to prevent consequences of an unhealthy situation due to accumulating toxic and hazardous emissions caused by open dumping of municipal solid waste with increasing urbanization has necessitated a renewed thinking on waste disposal. Grate fired incineration systems were adopted by urban managements in past and present but with criticisms due to formation of air borne emissions. Improved combustion methods like fluidized bed are now propagated because of current requirements like efficient energy recovery potential, stricter emission norms, adaptability with urban growth, adaptability to co-firing with other waste like biomass, edible oil wastes or industrial effluent and integration with conventional energy generation. Such a comprehensive and futuristic approach is more sustainable for the community. Multi-criteria decision-making tool is used to identify the best technology option among grate combustion and fluidized bed combustion for disposing and energy recovery from waste. Ten different collection and disposal options involving two combustion methods, namely, grate combustion and fluidized bed method are considered. Utilization of the energy is done for three end uses, namely, power generation, water distillation and district cooling. Two different regions in Saudi Arabia are considered for this study under two types of scenario, namely with recycling and without recycling. The different options are prioritized based on their overall ranking using five major performance factors.
ARTICLE | doi:10.20944/preprints202306.1586.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: solid waste management; waste treatment; environmental risk assessment; municipal waste; indoor air quality; gas emissions
Online: 22 June 2023 (09:41:30 CEST)
To date, only a few studies focused on carbon monoxide (CO) production during waste composting; all targeted on CO inside piles. Here, the CO net emissions from compost piles and the assessment of worker’s occupational risk of exposure to CO at large-scale composting plants are shown for the first time. CO net emissions were measured at two plants processing green waste, sewage sludge, or undersize fraction of municipal solid waste. Effects of the location of piles (hermetised hall vs. open yard) and turning (before vs. after) were studied. Higher CO net emission rates were observed from piles located in a closed hall. The average CO flux before turning was 23.25 and 0.60 mg‧m-2‧h-1 for hermetised and open piles, respectively, while after – 69.38 and 5.11 mg‧m-2‧h-1. The maximum CO net emissions occurred after the compost was turned (1.7x to 13.7x higher than before turning). The top sections of hermetised piles had greater CO emissions compared to sides. Additionally, 5% of measurement points of hermetised piles switched to ‘CO sinks’. The 1-h concentration in hermetised composting hall can reach max. ~50 mg CO∙m-3 before turning, and >115 mg CO∙m-3 after, exceeding the WHO thresholds for a 1-h and 15-min exposures, respectively.
ARTICLE | doi:10.20944/preprints202208.0401.v1
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: e-waste; e-waste mechanical pretreatment; disintegration; e-waste milling; printed circuit boards; precious metals
Online: 23 August 2022 (17:24:51 CEST)
Various metals and semiconductors containing Printed Circuit Boards (PCBs) are abundant in any electronic device equipped with controlling and computing features. These devices inevitably constitute E-waste after the end of service life. The typical construction of PCBs includes mechanically and chemically resistive materials, which significantly reduce the reaction rate or even avoid accessing chemical reagents (dissolvents) to target metals. Additionally, the presence of relatively reactive polymers and compounds from PCBs requires high energy consumption and reactive supply due to the formation of undesirable and sometimes environmentally hazardous reaction products. Preliminarily milling PCBs into powder is a promising method for increasing the reaction rate and avoiding liquid and gaseous emissions. Unfortunately, current state-of-the-art milling methods also lead to the presence of significantly more reactive polymers still adhered to milled target metal particles. This paper aims to find a novel single and two-stage disintegration-milling approach that can provide the formation of metal-rich particle size fractions. The morphology, particle fraction sizes, bulk density, and metal content in produced particles were measured and compared. Research results show the highest bulk density (up to 6.8 g·cm-3) and total metal content (up to 95.2 wt. %) in finest sieved fractions after the single-step milling of PCBs. Therefore, the concentrations of about half tested metallic elements are higher in the single milled specimen and with lower adhered plastics concentrations, as compared to double milled specimens.
ARTICLE | doi:10.20944/preprints202002.0312.v1
Subject: Engineering, Civil Engineering Keywords: recycling; concrete waste; wooden waste; heating compaction; bending strength
Online: 23 February 2020 (09:28:21 CET)
A large amount of concrete waste is generated around the world and its recycling is an urgent issue. In this research, a new approach to recycle concrete waste with wooden waste was studied. Concrete and wooden wastes were crushed, mixed, and heat compacted to produce plates with different water contents and mix proportions at various temperatures, pressures, and durations of compaction. The bending strength of the plates was measured after compaction. The result indicated that with an increase in the percentage of wooden waste in the mixture, pressure, or temperature improved the bending strength. The increase in water content reduced the bending strength. Most of the products exhibited higher bending strength than that of ordinary concrete.
ARTICLE | doi:10.20944/preprints202311.1266.v1
Subject: Engineering, Architecture, Building And Construction Keywords: refurbishment plasterboard waste; demolition plasterboard waste; gypsum waste recycling; acid leaching purification; wastewater treatment and valorization
Online: 21 November 2023 (09:35:46 CET)
Industries are required to utilize treatment technologies to reduce contaminants in wastewater prior discharge and valorize by-products to increase sustainability and competitiveness. Most acid leaching gypsum purification studies have obviated the treatment of the highly acidic wastewater produced. In this work, acidic wastewater from acid leaching purification of post-consumer gypsum was treated to recover a valuable solid product and reusable water. The main aims of this work were to determine the impact of recirculating acidic and treated wastewaters on the efficiency of the acid leaching purification process and to valorize the impurities in the wastewater. Samples were characterized through X-ray fluorescence and X-ray diffraction. SimaPro 9.5 and ReCiPe 2016 midpoint method were used for the life cycle assessment of three wastewater management approaches. The reuse of the acidic wastewater did not improve the chemical purity of gypsum. Soluble impurities were precipitated at pH 10.5 as a magnesium-rich gypsum that could be commercialized as fertilizer or soil ameliorant. The alkaline treated water was reused for 6 acid leaching purification cycles without impacting the efficiency of the purification process. An acid leaching-neutralization-filtration-precipitation approach demonstrated superior overall environmental performance. Barriers and enabling measures for the implementation of an in-house wastewater treatment were identified.
ARTICLE | doi:10.20944/preprints202012.0294.v1
Subject: Engineering, Automotive Engineering Keywords: construction and demolition waste; renovation; demolition; waste disposal; pre-renovation audit; waste audit; construction; comparison; costs
Online: 11 December 2020 (16:20:49 CET)
The issue of sustainability has long been the subject of interest of the architecture engineering and construction sector. All three aspects of sustainability - economic, environmental and social - can be affected through appropriate construction waste management. Construction and demolition waste (CDW) is one of the largest worldwide waste streams, therefore it is given great attention by all stakeholders (investors, contractors, authorities, etc.). Researches have shown that one of the main barriers to insufficiency CDW recovery is inadequate policies and legal frameworks to manage CDW. It is also one of the EU's environmental priorities. Aim of the article is to confirm the economic potential of construction and demolition waste audit processing through case study. A pre-demolition waste audit has been processed for unused building of shopping center in the town Snina in Slovakia. Subsequently, a comparison of economic parameters (waste disposal costs and transport costs) of recommended CDW management was performed. This comparison confirmed the economic benefits of environmentally friendly construction waste management methods according to the waste audit results, which will also increase the sustainability of construction projects. In addition, the cost parameters of selected waste disposal methods could be another dimension of building information modelling.
REVIEW | doi:10.20944/preprints202311.1728.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Enzymes; Biomass; Waste Management; Waste Treatment; Microorganisms; Applications of Enzymes
Online: 28 November 2023 (09:23:07 CET)
Enzymes are biological molecules produced by living entities for carrying out biological processes. The application of enzymes for waste treatment has been gaining pace commercially to solve concerns related to agricultural residues, wastewater, replacement of synthetic processes with natural ones, etc. The application of enzymes for waste management has been an environmentally reliable and sustainable process. Treatment of waste with enzymes such as xylanase, proteases, hydrolases, cellulose, peroxidases, chitinases, laccases, etc. has been studied to be effective. These enzymes act upon the waste products and transform them into biodegradable forms that can be recycled, reused and converted to value-added products. They have wide applications and utility as it has been an effective approach, economically cheaper and sustainable techniques. Application of such enzymes for waste management would be beneficial for reducing the quantity of waste, diminishing the negative effects of waste and pollution on the environment, and would be beneficial in bio-converting the waste products into alternate sources of energy. The current chapter focuses on different types of enzymes, their applications for waste management, and their limitations. This chapter also emphasizes the usage of some prominent microorganisms, their secreted enzymes and their proposed mechanisms of action involved with the degradation of the waste products.
ARTICLE | doi:10.20944/preprints202307.0317.v1
Subject: Engineering, Other Keywords: waste management; cigarette butts; tobacco products; waste collection; cigarette recycling
Online: 5 July 2023 (11:51:18 CEST)
Cigarette butts (CBs) are the most diffuse waste in the world, often abandoned in the environment without proper disposal. They are dangerous because of the numerous harmful chemicals poten-tially released in the environment. There are, in literature, several technological options for CB recycling, but some critical concerns could affect their effectiveness due to the quality and quantity of CB litter collected in the proper way. The present paper focuses on policy framework social behavior, waste collection and transport and technological processes. The Extended Producer Responsibility scheme for CBs is proposed at European level as an action to tackle CB litter and encourage sustainable product development. The CB waste collection and transport is a key step for bringing CB to the recycling process. The main concern is the small quantity of CBs collected: 0.06 % of the municipal waste and 0.18 % of the unsorted waste in the administrative area of Pe-rugia. Another crucial issue is the need for behavioral interventions to increase education and awareness of smoker citizens, addressing the discrepancy between smokers’ behaviors and beliefs.
REVIEW | doi:10.20944/preprints202302.0481.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Biomass valorization; Biotechnological techniques; Food waste; Fruit processing; Waste-utilization
Online: 28 February 2023 (01:59:39 CET)
Fruits are commonly used, fresh or processed, to prepare different industrial products with superior nutritional and health-promoting properties. Currently, the demand for processed fruit products has motivated the rapid growth of the fruit processing industries, persuading them to produce an enormous amount of by-products with less utilization. Furthermore, people's shifting dietary habits and lack of awareness of nutritional properties result in an avoidable load of fruit by-products. The knowledge of the value of by-products urges exploration with proper documentation, emphasizing the health benefits of some such products. Hence, this review is prepared by carefully analyzing the recent literature on industrial applications of fruit by-products and their nutritional and health-promoting properties. The use of fruit by-products in food industries for various purposes has been reported in the past and has been reviewed and described here. Fruit by-products are a good source of nutrients and bioactive components, including polyphenols, dietary fibers, and vitamins, implying that they could have an important role for novel, value-added functional food properties. Furthermore, fruit by-products are used as the substrate for the production of organic acids, essential oils, enzymes, fuel, biodegradable packaging materials, and preservatives.
ARTICLE | doi:10.20944/preprints202203.0092.v1
Subject: Engineering, Architecture, Building And Construction Keywords: Circular Economy; Built Environment; Reuse; Upcycling; Industrial Waste; Urban Waste
Online: 7 March 2022 (09:14:42 CET)
The growing concern about climate change and the recognition of the planet’s limits led society to look for alternatives that promote the balance between the natural and the built environment. The circular economy emerges as an alternative to the linear economic model, inspired by natural metabolisms, by circulating resources in continuous loops, where their intrinsic value is maintained and improved. This research proposes a closed-loop strategy in the built environment by studying innovative constructive solutions that aim to find use, value, and inspiration in what is considered waste. A literature review is conducted on the circular design strategies, re-use and recycle typologies, and waste transformation processes. Then, the development of a methodology for qualitative evaluation and selection of re-used and upcycled construction materials from post-consumer waste and by-products is presented and then applied to thirty-five cases of constructive solutions from plastic, wood, paper, steel, aluminium, and agricultural waste. The research reports that the developed framework is adequate. The analysed alternative materials have good environmental performance and can be used as building materials despite their functional limitations, reflecting the enormous potential of waste as a resource for the construction industry.
ARTICLE | doi:10.20944/preprints202009.0304.v2
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: COVID-19; waste generation; waste collection; gap assessment; emergency plans
Online: 23 June 2021 (11:39:27 CEST)
The nationwide lockdown imposed to control the spread of novel coronavirus induced dramatic alterations in different sectors of the Nepalese governance, including Solid Waste Management (SWM) practices. The study identifies SW collection gaps in seven major cities of Nepal and highlights the municipal and public households on SW management practices before and during the lockdown to emphasize the linkage between COVID-19 and SWM. It includes information on solid waste status, collection frequency and coverage, workers safety practices, types of vehicles operated for collection and alternative methods adopted by households to manage SW during the lockdown. For this, 1329 households survey and key informant interviews were conducted in seven cities of Nepal during the lockdown. It was found that although the coverage of the collection service was similar during the pandemic, there was a drastic decrease in the collection frequency leading to a collection gap of around 570 tons/day. More than 50% of the surveyed households adopted no proper alternative measures as they claimed that they stored solid waste with proper management so that municipal authorities can take it. The study reveals poor occupational health and safety practices among the solid waste workers due to the unavailability of safety gears and equipment despite being aware of the modes of transmission of the virus. The pandemic exacerbated the challenges of smooth SWM as it is an essential and needy service. This study highlights the need for a timely strategic management framework to be developed by the government to continue the smooth SWM practices during the lockdown.
CONCEPT PAPER | doi:10.20944/preprints202005.0024.v1
Subject: Engineering, Civil Engineering Keywords: recycling; circularity; concrete waste; wood waste; botanical concrete; heat pressing
Online: 3 May 2020 (06:20:37 CEST)
Botanical recycled concrete, or concrete bonded with wood, is formed by heat pressing the mixture of concrete and wooden waste. Botanical recycled concrete is a relatively new material and the relationship between production condition and its real-world performance is not clear yet. This experimental study investigated the influence of several production condition factors on the density and bending strength of botanical recycled concrete. As a result, temperature and mass ratio of concrete powder to wood flour presented significant effects on the density of this botanical recycled concrete. The increase in production temperature resulted in a remarkable increment in density and bending strength. This is probably due to increased wood flowability and accelerated compaction and bonding formation. The fineness of wood flour had a significant effect on improving bending strength. This is attributed to a larger contact surface between the wood substance and concrete particles.
ARTICLE | doi:10.20944/preprints201905.0183.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Anaerobic digestion; biogas; green energy; municipal solid waste; organic waste
Online: 15 May 2019 (10:33:58 CEST)
Global waste generation keeps increasing over the year and requires innovative solutions to minimize their impacts on environmental quality and public health. Predicted 2.2 billion tonnes per year of global municipal waste generation in the year 2025 which 1.6 fold is higher than in 2012. Hence, a strategic plan must be ascertained to overcome the future challenges of MSW locally and globally. Universiti Putra Malaysia (UPM) coined an initiative to demonstrate a showcase pilot plant for green energy production from MSW. Therefore, the data was obtained from the survey and actual sampling within the UPM compound to estimate the MSW generated and it's potentially used for green energy production. It is estimated that 5.0 – 7.0 tonne per day of MSW generated which about 30 - 35% is an organic fraction. Upon separation, the organic fractions were digested into biogas through anaerobic. At the maximum conversion of organic fraction, about 775 kWh of electricity may able to generate from the waste. In this study, the complete biorefinery setup and utilize organic components from the MSW generated in UPM was proposed that the biogas subsequently will be used to produce green energy in the form of electricity or cooking fuel.
CONCEPT PAPER | doi:10.20944/preprints202301.0444.v1
Subject: Physical Sciences, Radiation And Radiography Keywords: radioactive waste; radioactive waste processing; radioactive waste disposal; trinitite; radioactive gemstones; radioactive corundum; radioactive sapphire; radioactive ruby
Online: 25 January 2023 (04:14:53 CET)
The possibility of making precious stones from radioactive waste is being considered. Vitrified and cemented radioactive waste (RW) is considered as an artificial rock belonging to aluminosilicates and calcites. Two methods are proposed for the manufacture of radioactive gemstones from RW and their subsequent storage with the possibility of sale, resale, inheritance, and so on. That is, RW is considered as real estate in which capital can be invested. After decontamination in hundreds and thousands of years, it will be of scientific, historical, jewelry interest.
REVIEW | doi:10.20944/preprints202205.0009.v1
Subject: Engineering, Chemical Engineering Keywords: mineral waste; bio-base waste; natural fiber; biomass; sulfur waste; copper flotation; fly ash; biochar; sustainable construction
Online: 4 May 2022 (13:12:11 CEST)
The new climate law introduces a policy of sustainable construction, the assumption of which is the reduction of CO2 by the construction industry and the use of environmentally friendly materials, such as agricultural, mineral, and recycled waste, while limiting the consumption of natural resources. The article is a literature review that analyzes selected waste materials from various sectors of the economy that can be used as additives or partial substitutes for natural resources in the production of cement and in and cement building materials, the production of which reduces CO2 emissions, producing materials with high mechanical strength and environmentally friendly.
Subject: Business, Economics And Management, Economics Keywords: waste management; circular economy; sustainability; mechanical biological treatment; waste-to-energy; waste tax; green economy; landfills; composting
Online: 7 March 2020 (15:29:01 CET)
An adequate number of waste management facilities is the key element to meet circular economy goals. Using empirical data taken from official sources the research framework bases on an econometric model to compare the elasticity of cost on quantity of different alternatives such as waste-to-energy facilities, mechanical biological facilities and landfills impact on waste management cost. Results suggest that both waste-to-energy facilities (-0.278%) and landfills (-0.38%) concur to lower the cost while the higher the percentage of waste sent to mechanical biological treatment facilities, the higher the cost (0.788%). This figure deserves to be examined in more details as such facilities represent an intermediary step in the chain which efficiency depends on the industrial organization of the chain.
ARTICLE | doi:10.20944/preprints201707.0069.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: waste management; waste minimization; recycling; rural district municipalities; community residents; households; satisfaction levels; willingness to recycle; waste separation; municipal solid waste; benefits and barriers
Online: 25 July 2017 (05:14:07 CEST)
Whereas waste management research has focused on mostly urban municipalities in South Africa, not much is known about the current performance of waste management services from the perspective of community residents in rural municipalities. This study reports on the status and effectiveness of waste management practices from the perspective of community residents in the Umkhanyakude and Zululand Districts in the rural areas of the KwaZulu-Natal province of South Africa. Making use of structured questionnaires, primary data was obtained by interviewing 333 respondents representing households in the study area. Results have revealed several shortfalls in the provision of municipal waste management services, except for solid waste removal from households (66%), and management of landfill sites (41%). The degree of dissatisfaction for waste management services rendered was very high (97.3%). Furthermore, the majority (61.4%) of respondents were not willing to participate in waste segregation due to lack of appropriate knowledge and infrastructure. The study also pinpointed some benefits associated with waste minimization, as well as barriers constraining effective waste recycling. Based on these findings, there is a dire need for transforming current waste management practices toward increased recycling rates by creating more environmental awareness and a supporting infrastructure.
ARTICLE | doi:10.20944/preprints202307.0882.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: food waste; food waste disposers; catering wastewater; COVID-19 pandemic lockdowns; pollution loads; catering food waste energy potential
Online: 13 July 2023 (12:30:06 CEST)
The use of food waste disposers in gastronomical facilities influence the municipal wastewater composition. Ground food waste poses problems in the operation of the sewerage network and generates high electric energy consumption in wastewater treatment plants (WWTP). The study aimed to determine, for five towns with a PE of 4,000 to 220,000, the volumes of catering waste discharged to the WWTPs. The towns differed in the number of inhabitants, beds in hotel and catering places. The calculations were made based on data received from the operators of WWTP. The pollutant concentrations in 2019, were compared with data from the "pandemic" year - 2020. The loads of catering waste entering the sewerage system in 2019 ranged from 32.7 to 1062 tons. In town with the largest tourist base, the BOD value in 2020 accounted for 62.3% of 2019 value. In the largest town, the annual energy consumption for food waste treatment could be up to 2,539,770 kWh. If the waste was fermented, it could be obtained up to 1,376,650 m3 of methane. There is a strong need for implementing a collection system for food waste from catering facilities and its fermentation to produce methane, which can be used for energy purposes.
ARTICLE | doi:10.20944/preprints202310.1675.v1
Subject: Public Health And Healthcare, Health Policy And Services Keywords: Infectious waste management; Healthcare waste; Hospital; color coding; segregation; Public Health
Online: 26 October 2023 (03:28:53 CEST)
Any Hospital’s primary goal is to restore human health and save lives through health services provided to patients, but at the same time, hazardous wastes are produced. Inconsistent management of unsafe wastes might cause adverse effects and other issues to workers, the environment and public health. Segregation is considered the critical stage for a successful Healthcare Waste Management. Mixing hazardous waste with non-hazardous waste will be avoided by correctly applying practices at the segregation stage. This study aimed to assess personnel’s knowledge about Infectious Medical Waste and segregation practices used at six wards in Nicosia General Hospital. An analytical cross-sectional study was conducted, and data were collected through a structured self-administered questionnaire. The Statistical Package of Social Science (SPPS) version 25 was used with a minimum statistical significance α=0.05. The study population was nurses, nurse assistants, ward assistants and cleaners working at the study wards. Out of 191 questionnaires, 82 were received, with a response rate of 42.93%. Most participants were female (72%) and nurses (85,4%). Participants had medium to good knowledge about Infectious Medical Waste management and good knowledge regarding segregation practices applied in their ward. Segregation was not carried out as it should have since most participants stated that Infectious Medical Wastes were mixed with non-hazardous waste. Correct answers given by the participants regarding color-coding of different Healthcare Waste categories was 67.5%, and only four answered correctly to all questions. Although participants knew segregation practices and the colour-coding process applied for Healthcare Waste, they didn’t use them satisfactorily. They applied methods regarding segregation without specific training, knowledge and guidance. Due to the issue's importance, training programs must be implemented and performed.
ARTICLE | doi:10.20944/preprints202310.0628.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Solid waste management; waste classification; capacitive sensor; Machine Learning; ecological point.
Online: 10 October 2023 (10:57:35 CEST)
The management and classification of solid waste is one of the most important challenges around the world, in order to sustain economic growth and preserve the environment. The objective is to propose the use of Smart Ecological Points as a strategy to address the problem related to the solid waste management system at the source, which has become one of the biggest problems globally and Colombia is no exception. The article describes the current state of the problem in the country and in turn, presents the possibility of developing a prototype corresponding to a low-cost Smart Ecological Point supported by the use of an experimental capacitive sensor and Machine Learning algorithms, which will reduce the time necessary for the classification of recyclable and non recyclable waste, minimizing the health risks and increasing the percentage of waste that can be reused, by reducing the probability of being contaminated at the source, an aspect that is very common when done manually. According to the results obtained, it was evident that the proposed prototype made an adequate classification of waste, generating the possibility of being manufactured with existing technology in the environment, in order to promote adequate waste classification at the source.
ARTICLE | doi:10.20944/preprints202205.0198.v1
Subject: Physical Sciences, Radiation And Radiography Keywords: radioactive waste; radioactive waste recycling; industrial slag; industrial ash; aerospace industry
Online: 16 May 2022 (07:50:42 CEST)
The article discusses an alternative way of recycling radioactive waste (RW), presented in the form of radioactive building materials - concrete and reinforced concrete structures and metal fittings, with the further use of materials, obtained during recycling, in the space industry. That is, it is supposed to send radioactive waste into space not as a passive ballast, but as a payload that will operate in space under conditions of increased radiation.
ARTICLE | doi:10.20944/preprints202203.0159.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: insecticidal wastes; waste disposal; incineration; waste pit; environment; testing facility; climate
Online: 11 March 2022 (03:53:00 CET)
Insecticide testing facilities that evaluate a variety of vector control products may generate large amount of hazardous wastes from routine operations. These wastes originate from degraded technical grade materials, sprayed substrates, redundant stock or working insecticidal solutions. The washing of Long-Lasting Insecticidal Nets (LLINs) during preparation for laboratory and experimental hut trials also contribute to waste water with insecticide content. Human and environmental exposure to insecticidal waste can occur during transport, categorization, storage and disposal in resulting in environmental pollution and potential health effects. Various national and international guidelines have been devised for safe disposal and should be strictly followed to avoid adverse effects on humans or environment. The current paper describes a case study from insecticide test facility in north-eastern Tanzania in management of insecticidal waste.
ARTICLE | doi:10.20944/preprints202107.0427.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Solid waste management; LED lamp; characterization protocol; recycling; LED waste management
Online: 20 July 2021 (09:25:18 CEST)
Solid-state lighting has been replacing conventional lighting in the market, raising concerns for implementing an efficient end-of-life management system. Since LED waste streams have not been quite dominant, characterization studies (product-level characteristics, component-wise information, bill of materials, diversity, and differences) are inconsistent and having substantial gaps. This study investigates the end-of-life LED lamp literature, focusing on the bill-of-materials, and reveals that the characterization procedure suffers from a severe lack of sample representativeness. Consequently, characterization results are widely varied and not generalizable. Moreover, most of the studies did not inform and document the detailed sample characteristics, precluding the possibility of identifying reasons for variation. Combining available information from the recent studies, we present a mass distribution at the component level, exemplifying the prospect for meeting EU regulatory limit and the need for more insight at the lamp and component level. To fill the disconnection between lamp level characteristics and component and material content, we propose a characterization protocol that carefully documents lamp, component, and material level information by establishing a lamp-component–material composition nexus. The protocol may help researchers, policymakers, and industrial stakeholders conduct a systematic characterization, analyze complexities and prepare for a sustainable solution.
REVIEW | doi:10.20944/preprints202311.0935.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: manufacturing waste; sustainable energy generation; circular economy; future trends in waste utilization
Online: 14 November 2023 (13:35:42 CET)
The paper presents a thorough examination of the burgeoning field of utilizing manufacturing waste for sustainable energy generation, aligning with the global imperative for resource efficiency and clean energy solutions. With the manufacturing sector being a significant contributor to waste generation, this study explores innovative approaches to transform waste materials into valuable resources, thereby mitigating environmental impacts and contributing to a circular economy. This work critically reviews current trends, emphasizing technological advancements, policy interventions, and market dynamics shaping the manufacturing waste utilization landscape. Noteworthy developments, such as advanced sorting technologies and the integration of digital solutions, are discussed in detail, showcasing their role in enhancing the efficiency of waste management processes. The study outlines future trends in the field, anticipating a shift towards closed-loop systems guided by circular economy principles. This comprehensive review aims to contribute to the discourse on sustainable waste management and energy generation by providing a holistic perspective on the field's current state and offering insights into the future trajectories that will propel manufacturing waste toward a more sustainable and circular future. The synthesis of technological innovation, collaborative efforts, and evolving regulatory frameworks presents a compelling case for the continued exploration of manufacturing waste as a valuable resource in the pursuit of a more sustainable and energy-efficient world.
ARTICLE | doi:10.20944/preprints202310.0661.v1
Subject: Engineering, Civil Engineering Keywords: waste management; demolition waste generation; machine learning; artificial neural network; SHAP analysis
Online: 11 October 2023 (14:28:25 CEST)
In South Korea, demolition waste (DW) management has become increasingly significant owing to the rising number of old buildings. Effective DW management requires an efficient approach that accurately quantifies and predicts the generation of DW (DWG) of various types, which necessitates access to the required information or technology capable of achieving this. Hence, we developed an artificial intelligence-based model that predicts the generation of ten DW types, specifically from buildings in redevelopment areas. We used an artificial neural network algorithm with < 10 neurons in the hidden layer to derive individual input variables and optimal hyperparameters for each DW type. All DWG prediction models achieved an average validation and test prediction performance (R²) of 0.970 and 0.952, respectively, with their ratios of percent deviation ≥ 2.5, ver-ifying them as excellent models. Moreover, a Shapley additive explanations analysis revealed that DWG was most impacted by the floor area for all the DW types, with a positive correlation with DWG. Conversely, other factors showed either a positive or negative correlation with DWG de-pending on the DW type. The study findings will enable demolition companies and local gov-ernments in making informed decisions for efficient DW management and resource allocation by accurately predicting the generation of various types of DW.
ARTICLE | doi:10.20944/preprints202110.0454.v2
Subject: Engineering, Automotive Engineering Keywords: food waste recovery; maggot production; environmental protection; animal feed; solid waste management
Online: 24 January 2022 (14:16:03 CET)
Waste recovery is an important aspect towards human and environmental health protection. Unfortunately, proper food waste management is among the serious challenges in the field of solid waste management worldwide. Therefore, it is of great importance to conduct studies towards achieving efficient and cost-effective approaches for food waste management. This study investigated the potential of recovering food waste through maggots’ production as animal feed. The influence of fly attractant application on maggot production was also investigated. The study also investigated the potential of maggot production for waste recovery and reduction. Four different types of food waste (starch food leftovers, rotten bananas and peels, rotten pineapple and peels, and rotten oranges) were used in the investigation process. From the results, it was observed that the application of fly attractants had a significant effect on the production of maggots as determined by the weights after harvesting. Average weight of 94 g/kg of maggot was achieved from banana materials with an application of fly attractant during the 8th day of the cultivation; which is equivalent to a 32.4% increase from the same day when the material was cultured without applying fly attractant. Also, from the starch materials, about 77 g/kg of maggot weight was achieved; which is a 54.6% increase from the same day and the same material but without application of fly attractant. Moreover, the relative dry weight reduction in the trials varied from 52.5% to 82.4%.
ARTICLE | doi:10.20944/preprints201910.0203.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: actual recycling rate; material flow analysis; municipal solid waste; waste treatment charge
Online: 17 October 2019 (15:02:13 CEST)
The recycling, incineration, and final disposal rate of municipal solid waste (MSW) are calculated based on the total amount of waste input to each facility in many countries. These statistic data have serious limitation in setting the national goal and policy for effective waste management because it is not considering the amount of foreign objectives in the process of each life-cycle stage. This case study is to estimate the actual rates of recycling, incineration, and final disposal by material flow analysis (MFA) after the collection of MSW in Korea. The actual rates of recycling, incineration and final disposal for MSW in 2016 were 49.9%, 32.9% and 23.1% respectively, indicating that the recycling rate was lower by 10.1%, while the incineration and final disposal rates were raised by 7.6% and 8.4% respectively, compared with the statistics for current MSW. In addition, the changed actual rates of recycling, incineration treatment, and final landfill, and variation of waste treatment charge according to treated amounts per treatment method was analyzed. This results of this study will contribute to establish national level of plan on effective waste management.
ARTICLE | doi:10.20944/preprints202312.0143.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: SDG12.3; food waste; food waste recycling law; recycling as feed; food waste reduction promotion act; Japan
Online: 4 December 2023 (07:53:53 CET)
SDG target 12.3 calls for halving food waste at retail, food service, and household by 2030. The food waste index for this purpose includes parts attached to food that are usually removed intentionally ("unavoidable food waste") and allows counting the conversion to animal feed and utilisation as biomaterial as means of reduction. In Japan, the "Food Waste Recycling Law" which has been in effect since 2001, promotes the recycling of food waste generated from businesses, designating feed conversion as top priority. On the other hand, based on the more recent "Food Loss Reduction Promotion Act" of 2019, the government is currently promoting the reduction of avoidable food waste, as to meet the SDG target. Based on statistical sources and interviews with Ministry officers, this paper explains the history and achievements of Japan's 23-year policy based on the Food Recycling Law, as well as the tension between the two legislations.
ARTICLE | doi:10.20944/preprints201904.0153.v1
Subject: Engineering, Energy And Fuel Technology Keywords: nuclear waste isolation; horizontal disposal drillholes; directional drilling; engineered barrier system, spent nuclear fuel, waste repository, geologic disposal; high level waste
Online: 13 April 2019 (05:11:28 CEST)
Spent nuclear fuel and high-level radioactive waste can be disposed in deep horizontal drillholes in sedimentary, metamorphic, or igneous rocks. Horizontal drillhole disposal has safety, operational, and economic benefits: The repository is deep in the brine-saturated zone far below aquifers in a reducing environment of formations that can be shown to have been isolated from the surface for millions of years; its depth provides safety against inadvertent intrusion, earth¬quakes, and near-surface perturbations; it can be placed close to the reactors and interim storage facilities, minimizing transportation; disposal costs per ton of waste can be kept substantially lower than for mined repositories by its smaller size, reduced infrastructure needs, and staged imple¬mentation; and, if desired, the waste could be retrieved using “fishing” technology. In the proposed disposal concept, corrosion-resistant canisters containing unmodified fuel assemblies from commercial reactors would be placed end-to-end in up to 50 cm diameter horizontal drill¬holes, a configuration that reduces mechanical stresses and keeps the temperatures below the boiling point of the brine. Other high-level wastes, such as capsules containing 137Cs and 90Sr, can be disposed in small-diameter drillholes. We provide an overview of this novel disposal concept and its technology, discuss some of its safety aspects, and compare it to mined repositories and the deep vertical borehole disposal concept.
ARTICLE | doi:10.20944/preprints202307.1529.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: wool waste; wool keratin; deep eutectic solvent; electrospinning; gel-based nanofibers; waste valorization
Online: 24 July 2023 (03:07:39 CEST)
Millions of tons of wool waste are produced yearly by textile industries, which may become a serious environmental hazard in the near future. Given this concern, it is crucial to explore strategies to reduce the amount of wool waste generated worldwide and adopt more sustainable practices for dissolving and regenerating wool keratin (WK) from textile waste. Most traditional methods involve the use of expensive, toxic, harmful, and poorly biodegradable compounds. To overcome these limitations and facilitate the reuse of wool waste through a cascade valorization strategy, researchers have started testing the use of deep eutectic solvents (DES) as a more sus-tainable and eco-friendlier alternative for WK dissolution and regeneration. In this study, the potential of two different DES mixtures, Choline chloride (ChCl): Urea and L-Cysteine (L-Cys): Lactic acid (LA), was explored for dissolving wool waste. Subsequently, the obtained gels based on DES-WK were blended with polyvinyl alcohol (PVA) in different ratios to produce nanofibers using the electrospinning technique. The effect of pH and the properties of the electrospinning solutions, namely electrical conductivity and viscosity, on the morphology of the gel solutions were evaluated. Moreover, the morphological features of the produced gel-based electrospun PVA/DES-WK nanofibrous membranes were analyzed using scanning electron mi-croscopy (SEM). Additionally, the PVA/L-Cys: LA DES-WK, which proved to be the most effective DES mixture for fabricating WK gel-based nanofibers, were characterized through Fourier transform infrared spectroscopy (FTIR) and tensile tests. Furthermore, their antioxidant and an-timicrobial abilities were evaluated. The results obtained revealed that this approach to valorize textile waste offers a unique avenue for the development of sustainable functional materials with potential applications in various biomedical and industrial fields.
ARTICLE | doi:10.20944/preprints202003.0264.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: recycling; composting; waste-to-energy; incineration; municipal solid waste; circular economy; green jobs
Online: 17 March 2020 (03:46:53 CET)
Sharing the same raw material, recycling and composting are in direct conflict with incineration of municipal solid waste in combined heath and power plants. Indeed, waste-to-energy plants in regions with high recycling rates import urban waste from other countries to use otherwise unused capacity, and raise revenues. Using the case of Italy’s second largest and economically most developed region, I discuss the economic viability of municipal solid waste incineration to produce electricity and heath in the context of the increasing role of electricity production from renewable energy sources as well as of the emerging mass-scale uptake of bioplastics. Four lessons and three guidelines aimed to local authorities and policy makers emerge from the present study.
ARTICLE | doi:10.20944/preprints201806.0214.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: Lean, Just in Time, Pull System, Waste Management, Sustainable improvement, Waste flow Mapping.
Online: 13 June 2018 (14:33:00 CEST)
Lean is one of the systematic approach to achieve higher value for organizations through eliminate non-value-added activities. It is an integrated set of tools, techniques, and principles designed to optimize cost, quality and delivery while improving safety. In Vietnam, industry waste management and treatment has become serious issue. The aim of this research is to present the effective of Lean application for industrial wastes collecting and delivery improvement. Through a case study, this paper showed the way of Lean tools and principles applied for wastes management and treatment such as Value Stream Mapping, Pull system, Visual Control, and Andon.... to get benefit on both economic and environment. In addition, the results introduced a good experience for Vietnamese enterprises in cost saving and sustainable development in waste management.
ARTICLE | doi:10.20944/preprints202206.0430.v3
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: cat; Tehran; weight loss; food access; waste reduction
Online: 13 October 2022 (11:34:42 CEST)
This study aimed to investigate the effect of reducing the amount of organic waste on the weight of cats in Tehran. The weight of 4192 cats was measured from spring 2016 to the end of winter 2020. They were classified into 6 age groups, 2 gender groups, and 13 geographical areas. Their weight was measured for 48 months (16 seasons). The statistical parameters analysis showed no weight loss in 2017, but since 2018, cats have been losing weight every year. They had lost about 178g of their weight in 2018. The sharpest annual decrease was observed in 2019 when about 301g of weight loss was recorded. In the winter of 2020, 115g of weight loss took place. In the spring of 2017, no weight change was observed, but in the spring of 2018, the cats lost 155g of their weight. Their weight loss intensified in the spring of 2019 and about 299g of weight loss was observed. In the summer of 2017, as in the spring of the same year, no weight loss was recorded, but for the summer of 2018, the weight loss was evident and about 205g of the weight of the cats had been reduced. The weight loss in the summer of 2019 not only continued but intensified and about 304g of weight loss was recorded for cats. Weight change was not observed in the fall of 2017 as in the spring and summer of the same year. In the fall of 2018, weight loss was recorded for cats. They had lost about 324g of their weight in the fall of 2018. Also, they experienced a weight loss of about 218g in the fall of 2019. During the spring, summer, and autumn of 2017, no weight loss was observed in the cats for the winter of 2018, but in the winter of 2019, the cats faced the most severe weight loss (seasonally). They lost about 401g of weight in the winter of 2019. Of course, in the winter of 2020, about 186g of weight loss was observed in cats. The results showed that female cats did not lose weight in 2017 but experienced weight loss in 2018 with a weight loss of 181g. The weight loss of females intensified in 2019 and 294g of weight loss was recorded. Female cats lost 186g of their weight in the winter of 2020. Male cats did not lose weight like female cats in 2017. But in 2018, a weight loss of 166g was observed in male cats. The weight loss of male cats continued in 2019 and 311g of weight loss was recorded for them. However, in 2020, unlike females, weight loss was not observed in male cats. It can be said that both sexes lost more weight in the winter of 2019 than in other seasons. In 2017, weight loss was observed only for the region of 10, and in the same year, weight gain was recorded for the region of 15. But in 2018, except for regions 3, 4, 15, and 19, weight loss was observed in other regions. In 2019, the weight loss of cats spread and weight loss was observed in all regions except the region of 12. In winter 2020, weight loss was recorded only in the region of 4. In the end, it can be concluded that the weight of cats has decreased since the spring of 2018 because the beginning of the decrease in the amount of organic waste has been recorded since the winter of 2018. So, there is a direct relationship between the weight of cats and the amount of organic waste (access to food). The amount of garbage has been decreasing since the winter of 2018, and the average weight of cats has also been decreasing since the spring of 2018 due to the decrease in access to food.
REVIEW | doi:10.20944/preprints202207.0010.v1
Subject: Engineering, Architecture, Building And Construction Keywords: mining; tailings; waste; recycling; restoration
Online: 1 July 2022 (09:00:31 CEST)
Mining is an important industry that provides products and services through infrastructure systems worldwide. However, the global development promotes the steady growth and accelerated demand for minerals, resulting in the accumulation of hazardous waste in land, sea and air environments and, consequently a series of environmental and health problems. Restoration techniques from mining tailing have become increasingly discussed among scholars due to their potential to offer benefits over reducing tailings levels, thereby reducing environmental pressure for the correct management and adding value to previously discarded waste. This review paper critically explores available literature on the main techniques of mining tailing recycling, and discusses leading recycling technologies, including the advantages and drawbacks, as well as future perspectives. The findings of this review contribute as a reference for scholars as well as support for decisionmakers concerning the related environmental issues.
ARTICLE | doi:10.20944/preprints202112.0099.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: forest experience; open dump; waste
Online: 7 December 2021 (11:30:56 CET)
Forest recreation can be successfully used for the psychological relaxation of respondents and can be used as a remedy for common problems with stress. The special form of forest recreation intended for restoration is forest bathing. These activities might be distracted by some factors, such as viewing buildings in the forest or using a computer in nature, which interrupt psychological relaxation. One factor that might interrupt psychological relaxation is the occurrence of an open dump in the forest during an outdoor experience. To test the hypothesis that an open dump might decrease psychological relaxation, a case study was planned that used a randomized, controlled crossover design. For this purpose, two groups of healthy young adults viewed a control forest or a forest with an open dump in reverse order and filled in psychological questionnaires after each stimulus. A pretest was used. Participants wore oblique eye patches to stop their visual stimulation before the experimental stimulation, and the physical environment was monitored. The results were analyzed using the two-way repeated measures ANOVA. The measured negative psychological indicators significantly increased after viewing the forest with waste, and the five indicators of the Profile of Mood States increased: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Fatigue, and Confusion. In addition, the negative aspect of the Positive and Negative Affect Schedule increased in comparison to the control and pretest. The measured positive indicators significantly decreased after viewing the forest with waste, the positive aspect of the Positive and Negative Affect Schedule decreased, and the Restorative Outcome Scale and Subjective Vitality scores decreased (in comparison to the control and pretest). The occurrence of an open dump in the forest might interrupt a normal restorative experience in the forest by reducing psychological relaxation. Nevertheless, the mechanism of these relevancies is not known, and thus, it will be further investigated. In addition, in a future study, the size of the impact of these open dumps on normal everyday experiences should be investigated. It is proposed that different mechanisms might be responsible for these reactions; however, the aim of this manuscript is to only measure this reaction. The identified psychological reasons for these mechanisms can be assessed in further studies.
ARTICLE | doi:10.20944/preprints202110.0044.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Hydrogel; Keratin; Chicken feather waste
Online: 4 October 2021 (10:49:24 CEST)
The aim of this research study was to develop hydrogels samples for using in potential biomedical applications. Hydrogels consisting of different volumes of keratin, polyvinyl alcohol (PVA), Polyvinylpyrrolidone (PVP), and starch. The keratin is derived from the chicken was the primary material on the hydrogels due to attractively for the potential wound healing application. The hydrogel samples were made by using the freeze‑thawing method, and they were examined using the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), porosity amusement, swelling ratio and keratin release kinetic models that analyzed using (zero-order, first-order Higuchi and Korsmeyer-Peppas models). These results were indicated that feather keratin could use with formulated hydrogels suitably for controlled keratin release studies .
CONCEPT PAPER | doi:10.20944/preprints202105.0740.v1
Subject: Engineering, Architecture, Building And Construction Keywords: Food waste, recycling, construction materials
Online: 31 May 2021 (11:01:15 CEST)
Highlights: A new material with a bending strength higher than that of concrete was developed using vegetable or fruit waste. The new material maintains the color, taste, and flavor of the original vegetable or fruit. Without water resistant treatment, the material is edible and can be conditioned with seasonings
COMMUNICATION | doi:10.20944/preprints202102.0556.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Waste; environment; reuse; recycle; product
Online: 24 February 2021 (16:41:43 CET)
Solid waste management is a global issue that affects every individual living in the world directly or indirectly. Failing to manage the waste properly will cause harm on public health, our natural environment, and even our happiness and prosperity. When asked about the reason behind the failure of third time plastic ban in Bhutan, one of the Bhutanese said it’s because of the lack of cooperation from public to support the move of government. Clean Bhutan, a non-governmental organization (NGO) that aims Zero Waste Bhutan by 2030, has collected around 5,900 metric tons of waste from December 2014 to February 2018. This project will create some awareness regarding the management of waste at individual level when people come in contact with the family of the researcher. It also talks abot how waste management and biodiversity conservation can go side by side.
ARTICLE | doi:10.20944/preprints201807.0259.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: work accidents; drivers; waste; Finland
Online: 16 July 2018 (07:54:19 CEST)
Resilience embodies the personal qualities that enable one to thrive in the face of adversity. A previous Italian study showed that injured workers had a lower level of resilience than non-injured workers. The aim of this paper is to examine the relationship between occupational injuries and psychological resilience. The subjects were 197 drivers from two Finnish waste transport companies. As a part of larger questionnaire, they fulfilled the Connor-Davidson Resilience Scale, which consisted of 25 items. Drivers reported their occupational injuries during the last three years. The drivers involved in occupational injuries had higher score (average 69.3) on Connor-Davidson Resilience Scale than drivers avoided injuries (67.7). According to Student’s t-test the difference between groups was highly significant (t = 40.44, df = 196, p<0.001). The result of this study was contradictory to earlier Italian study. One explanation may be that the Italian study was done with traumatic context with seriously injured patients. Waste transport drivers were rather young and fit males, who had suffered only minor injuries.
ARTICLE | doi:10.20944/preprints202311.1836.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Hemp; agro-waste; deep eutectic solvents; electrospinning; gel-based blends; waste valorization; nanocomposite gels
Online: 29 November 2023 (09:47:16 CET)
Natural fibers have attracted increasing interest as an alternative to produce environmentally friendly and sustainable materials. Particularly, hemp fibers have revealed to be widely used in various industrial applications due to their extremely unique properties. However, hemp can generate a large amount of agro-waste, and results in an attractive source of biopolymers for the development of low-cost materials in alternative to the raw materials and conventional petroleum-based plastics. In addition, deep eutectic solvents (DESs), a new type of truly green solvents, have been tested to remove gums, lignin, and other non-cellulosic components from hemp fibers. Reusing these components dissolved into the DESs to fabricate new materials directly by electrospinning is a very attractive but still unexplored endeavor. Thus, this innovative research to venture new upcycling pathways is focused on the fabrication of composite nanofibers by electrospinning of a gel-based blend of Poly(vinyl alcohol) (PVA) and hemp agro-waste (HW) dissolved into choline chloride (ChCl) : Glycerol (1:2) and ChCl : Urea (1:2) DES mixtures. The results obtained revealed that the produced nanofibers displayed uniform appearance with diameters ranging from 257.72 ± 65.63 nm to 380.78 ± 133.98 nm. In addition, the mechanical properties of the electro-spun composite nanofibers produced from the gel-based blends of HW dissolved in DESs and PVA (HW-DESs_PVA) were found to be superior, resulting in an enhanced tensile strength and Young’s modulus. Furthermore, the incorporation of HW into the nanofibers was able to provide bioactive antioxidant and antibacterial properties. Overall, this study demonstrated a promising, more sustainable, and eco-friendly way to produce electrospun composite nanofibers using HW in a circular economy perspective.
ARTICLE | doi:10.20944/preprints202311.0347.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: classification; machine learning; deep learning; convolution neural networks; dataset; landfill waste; waste management; sustainability
Online: 7 November 2023 (02:50:04 CET)
The accurate classification of landfill waste diversion plays a critical role in efficient waste management practices. Traditional approaches, such as visual inspection, weighing and volume measurement, and manual sorting, have been widely used but suffer from subjectivity, scalability, and labour requirements. In contrast, machine learning approaches, particularly Convolutional Neural Networks (CNN), have emerged as powerful deep learning models for waste detection and classification. This paper analyses VGG-16, InceptionResNetV2, DenseNet121, Inception V3, and MobileNetV2 models to classify real-life waste when trained on pristine and unadulterated materials, versus samples collected at a landfill site. When training on DiversionNet, the unadulterated material dataset with labels required for landfill modelling, classification accuracy was limited to 49.69% in the real environment. Using real-world samples in the newly formed RealWaste dataset showed that practical applications for deep learning in waste classification is possible, with Inception V3 reaching 89.19% classification accuracy on the full spectrum of labels required for accurate modelling.
ARTICLE | doi:10.20944/preprints202307.1602.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Thermal plasma; mass separation; Nuclear waste treatment; High-level radioactive waste treatment; material processing
Online: 25 July 2023 (03:22:56 CEST)
Solid spent nuclear fuel from nuclear power plants has 3.4% fission products (80-160amu), contributing to over 99.8% radioactivity. On the other hand, liquid high-level radioactive waste (HLRW) from spent fuel reprocessing has 98.9% bulk elements (0-60amu) with 0.1% radioactivity. A separation mechanism on the mass categories as groups presents unique opportunities in managing HLRW for the long term with a considerable cost reduction. This paper proposes a thermal plasma-based separation system incorporating atmospheric pressure plasma torches for HLRW mass separation into low-resolution mass groups. Several engineering issues, such as waste preparation, waste injection into the plasma and waste collecting after mass separation, need to be addressed. Using COMSOL Multiphysics simulation, the generic system can be studied using noble gas mass separation and further analyze the mass filter capabilities. This paper provides the history of plasma-based mass separation. Functional modelling of a thermal plasma mass separation system is proposed under atmospheric pressure. Finally, aspects of mass separation simulation using noble gas Argon and Helium inside the plasma mass separation system were studied in COMSOL Multiphysics.
ARTICLE | doi:10.20944/preprints201907.0325.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: biomethane; d-limonene; flavanones; food waste; green extraction; hydrodynamic cavitation; orange waste; pectin; polyphenols
Online: 29 July 2019 (04:04:30 CEST)
Waste orange peel represents a heavy burden for the orange juice industry, estimated in several million tons per year worldwide; nevertheless, this by-product is endowed with valuable bioactive compounds, such as pectin, polyphenols and terpenes. The potential value of the waste orange peel has stimulated the search for extraction processes, alternative or complementary to landfilling or to the integral energy conversion. This study introduces controlled hydrodynamic cavitation processes, as a new route to the integral valorization of this by-product, based on simple equipment, speed, effectiveness and efficiency, scalability, and compliance with green extraction principles. Waste orange peel, in batches of several kg, was processed in more than 100 L of water, absent any other raw materials, in a device comprising a Venturi-shaped cavitation reactor. The extractions of pectin, endowed with a very low degree of esterification, polyphenols (flavanones and hydroxycinnamic acid derivatives), and terpenes (mainly d-limonene) were effective and fast (high yield, few min of process time), as well as the biomethane generation potential of the process residues was effectively exploited. The achieved results proved the viability of the proposed route to the integral valorization of waste orange peel, though wide margins exist for further improvements.
ARTICLE | doi:10.20944/preprints201807.0172.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Urban wastes; hospitality sector; waste generation rates; artificial neural network prediction; sustainable waste management.
Online: 10 July 2018 (11:45:39 CEST)
This study was undertaken to forecast waste generation rates of accommodation sector of North Cyprus as a case. Three predictor models including multiple linear regression (MLR), artificial neural networks (ANNs) and central composite design (CCD) were applied to predict the waste generation rate during the lean and peak seasons. ANN showed highest prediction performance, specifically, lowest values of the standard error of prediction (SEP = 2.153), mean absolute error (MAE=1.378) and highest R2 value (0.998) confirmed the accuracy of the model. The analysed wastes were categorised into recyclable, general waste and food residues. The authors estimated the total waste generated during the lean season as 2010.5 kg/day, in which large-sized hotel accounted for largest fraction (66.7%), followed by the medium hotels (19.4%) and guesthouse accounted for smallest part (2.6%). During the peak season, about 49.6% increases in the waste generation rates were obtained. Interestingly, 45% of the wastes were generated by the British tourists while the least waste was generated by African tourists (7.5%). The ANN predicted that the small and large hotels would produce 5.45 and 22.24 tons of waste by the year 2020, respectively. The findings herein are promising and useful in establishing a sustainable waste management system.
ARTICLE | doi:10.20944/preprints201611.0025.v1
Subject: Engineering, Control And Systems Engineering Keywords: waste management; economic instruments; pay-as-you-throw; municipal solid waste; recycling; environmental management
Online: 3 November 2016 (10:28:43 CET)
The “Pay-as-you-throw” scheme, PAYT, is an economic instrument of waste management that implements the “polluter pays” principle by charging inhabitants of municipalities according to the amount of residual, organic and bulky waste they send for third-party waste management. When combined with well-developed infrastructure to collect the different waste fractions (residual waste, paper and cardboard, plastics, bio waste, green cuttings, many recyclables) as well as with a good level of citizen’s awareness, its performance has frequently been linked to high collection rates of recyclables. However, the establishment and operation of PAYT systems can require significant resource inputs from municipalities. In this paper, PAYT is analysed through a case study from the German County of Aschaffenburg, covering nearly 20 years of implementation across 173,000 inhabitants. Key performance indicators applied include temporal trends in the county’s recyclables collection rate, waste treatment fees for residents and municipal waste management costs, benchmarked against German municipalities not implementing PAYT.
ARTICLE | doi:10.20944/preprints202307.1407.v1
Subject: Engineering, Mechanical Engineering Keywords: Agricultural waste utilization; Waste reuse, recycling, and recovery; Recycling and reuse of waste plastic film; Fluid-solid coupling simulation; bonding V2 model; agglomerate disaggregation
Online: 20 July 2023 (10:11:20 CEST)
A tumbler screen type residual film–impurity mixture wind separator as a key equipment for secondary utilization of farmland residual film. During the working process, the proportion of impurities in the separated waste mulch film intermittently increases, resulting in poor working stability of the device, which may hamper long-term operation. In this study, the material inside the separation unit was continuously monitored, and the main factor affecting separator per-formance was determined to be the challenges in the effective depolymerization of some residual film–impurity mixtures. The principles of agglomeration and depolymerization of the residual film–impurity mixtures were analyzed using computational fluid dynamics (CFD) and discrete element method (DEM) flow-solid coupling simulation methods. The key factor affecting the disaggregation of the mixture was the collision force between the residual film–impurity mixture and the trommel screen. The collision force was maximum when the residual film–impurity mixture first collided with the trommel screen when it was fed into the separation device. As determined by force analyses, the key factors affecting the collision force of the process were the material feeding amount and the structure of the inlet. Furthermore, simulations were carried out for different inlet structure forms; the evaluation index was the maximum collision force of the residual film–impurity mixture agglomerate on the trommel screen. The best disaggregation effect was obtained with a square feed inlet and at a feeding rate of 202 kg/h. A prototype was built using these specifications for verification. The average value of the ratio of impurities in the re-sidual film was 6.966%, the coefficient of variation was 7.38%, and the dispersion of statistical results was small. The ratio of impurities in the residual film was kept constant during the con-tinuous operation of the wind separator. Thus, this study analyzed the agglomerate disaggregation process and provided theoretical insights for deter-mining the optimal structures of the inlets of various cleaning devices and the feeding volumes.
ARTICLE | doi:10.20944/preprints202310.1180.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: Source-separated kitchen waste; Simultaneous saccharification and fermentation; Bioethanol yield; Pilot-Scale; Fresh food waste
Online: 22 October 2023 (09:05:10 CEST)
By the end of 2023, biowaste must be completely separated or recycled at source based on the EU legislation. Separate biowaste collection and valorisation towards biofuels could play an essential role in the biobased circular economy. In this context, the principal goal of this paper was to demonstrate in pilot scale the technological solution of bioethanol production via the utilisation of urban source-separated biowaste within the city context of Athens, Greece. More specifically, the main aim was the demonstration of a pilot system in continuous operation (over 10 operating cycles) with real feedstock – wet separately collected biowaste. From the 11 pilot trials performed with wet feedstock, the mean starch and cellulose degradation of the pilot trials amounted up to 80.69±16.27% and 79.41±10.37% respectively, while the bioethanol yield was 74.05±6.82%. The latter was comparable to that of more intensive pretreatment methods. Homogenization and shredding that was applied in this study, stand as promising and cost-effective pretreatment methods for bioethanol production from wet feedstock. Further research is needed to optimize conditions and evaluate scalability. Nevertheless, pilot scale testing is a crucial step in the development and deployment of this technology since it serves as a bridge between laboratory research and full-scale implementation, offering a practical and controlled environment to validate and optimize the technology while minimizing risks and uncertainties.
ARTICLE | doi:10.20944/preprints202005.0418.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: geological risk; pre-Neogene basement; radioactive waste; waste disposal; Northern Croatia; Probability of Success (PoS)
Online: 26 May 2020 (04:11:18 CEST)
The basic principles of geological risk calculation through Probability of Success (PoS) are mostly applied for numerical estimation of additional hydrocarbon existence in proven reservoirs or potential hydrocarbon discoveries in selected geological regional subsurface volume. It can be tailored and validated for a comprehensive input dataset collected in the selected petroleum province, adapted by dividing up geological events into several probability categories and classes. The most applied categories are (existence of) reservoir rocks, traps and isolators, source rocks, migration pathways and preservation conditions for hydrocarbons The methodology results in unique probability values as multiplication of independent statistical events, which can also be applied in the assessment of a potential hydrocarbon discovery of desired minimal volume and its value in any virtual currency like risk-neutral dollars. Such methodology has been extensively developed in the last decades in the Croatian subsurface, mostly in the Croatian part of the Pannonian Basin System (CPBS). Through the adaptation of geological categories, it was also applied in hybrid, i.e., stochastical, models developed in the CPBS (Drava Depression). Stochastically estimation of porosity was already applied. As the robustness of this methodology is very high, it was also modified to estimate the influence of water-flooding in increasing oil recovery in some proven Neogene sandstone reservoirs in the CPBS (Sava Depression). This new modification is being presented to be applied to geological risk calculation, intending to assess the safety of geological environment in deep wells, where depleted radioactive fuel would be disposed, a subject of great importance. The case study encompassed the magmatic and metamorphic rocks in the pre-Neogene basement of the CPBS. For disposal purpose, these are regionally lithologies considered as to be the safest ones considering petrophysical values, water saturation, recent weathering and tectonic activity.
ARTICLE | doi:10.20944/preprints202312.0298.v1
Subject: Architecture, Building And Construction, Engineering Keywords: alkali activation; geopolymers; glass waste; recycling
Online: 6 December 2023 (03:19:49 CET)
The recycling of common soda-lime glass (SLG) is far from being complete, since the material may contain small polymeric, metallic and ceramic contaminations. This has a negative impact on the quality of new glass articles prepared via re-melting. Alternatively, the full reuse of contaminated cullets could be achieved by low-temperature consolidation into geopolymer-like materials. SLG powders, used either as received or pre-washed in acid solution, were added to a sodium aluminate solution at the room temperature for 3 h, under low-speed mechanical stirring. Microporous semi-crystalline monoliths were formed by the casting of suspensions in plastic molds and cured at 75°C overnight. The monoliths featured hydrosodalite as the main crystalline phase for as received SLG and LTA zeolite in the case of pre-washed SLG. The mechanical properties compared well with those of cementitious materials. Moreover, by addition of coarse glass particles as fillers, the methodology successfully yielded Venetian terrazzo-like samples, which could lead to significant material and energy savings in their manufacture. The proposed approach could also be extended to other difficult-to-reuse glass formulations and provide attractive and versatile up-cycled materials.
REVIEW | doi:10.20944/preprints202310.0873.v1
Subject: Engineering, Civil Engineering Keywords: waste concrete; recycled aggregate; enhance; review
Online: 13 October 2023 (09:49:35 CEST)
The performance of recycled aggregate concrete deteriorates due to the defects of adhesive mortar, pores and cracks on the surface of recycled aggregate. It is of great engineering significance to modify the reclaimed aggregate to improve its performance and adaptability. In this paper, the physical and chemical properties of waste concrete recycled aggregate are reviewed. Then, the existing modification methods and technologies of recycled aggregate, including physical, chemical and biological methods, are reviewed. Finally, the existing problems of the current modification technology are summarized, and the future research direction is proposed. It is expected to provide a new idea and method for the modification of waste concrete recycled aggregate.
ARTICLE | doi:10.20944/preprints202310.0422.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: compost; organic fertilizer; sweet corn; waste
Online: 8 October 2023 (04:32:46 CEST)
Organic fertilizers are fertilizers made from organic materials which are partly or wholly derived from waste materials, the function of these fertilizers is to improve the physical, biological, and chemical properties of the soil, these fertilizers are processed through the composting process, these fertilizers are very much needed because they are difficult to obtain at a high price. expensive. This study aims to obtain data on the growth and yield of sweet corn, due to the use of agricultural waste as organic fertilizer. The research method was experimentally consisting of 5 treatments and 5 replications; ie P0 = Without organic fertilizer (control) P1 = Dosage of organic fertilizer 2.5 tons/ha, P2 = Dosage of organic fertilizer 5 tons/ha P3 = Dosage of organic fertilizer 7.5 tons/ha, P4 = Dosage of organic fertilizer 10 tons /ha using a Randomized Block Design (RBD) The results showed that organic fertilizer had a significant effect on plant height aged 30, 40 and 50 DAP, had a very significant effect on cob length at a dose of 10 t.ha-1 and, had no significant effect on cob weight, will still have a high weight of 350 g.cob-1 From this description it can be concluded that organic compost can be used as a substitute for chemical fertilizers which provides an increase in the growth and production of sweet corn plants at the use of 10 tons/ha.
REVIEW | doi:10.20944/preprints202308.1142.v1
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: sustainable solid waste management; recycling; composting
Online: 16 August 2023 (08:09:27 CEST)
This scoping review examines global strategies and enterprises for sustainable solid waste management, with a focus on alternative landfilling approaches. The study collected and analyzed a significant number of documents from different regions, revealing Asia as the major contributor (for the collected documents) (48.7%), followed by North America (24.3%) and Europe (15.8%). Recycling emerged as the most effective alternative waste treatment method, representing 52.3% of the documented approaches, with industrial recycling (22.6%) and residential/non-residential recycling (20.2%) as prominent categories. Food waste was a significant concern across regions, constituting 21.4% of the collected documents. Composting was widely adopted (15.4%) due to its simplicity and benefits for gardening and soil improvement. Other methods like biogas extraction, reusing, raising awareness, incinerating, redistributing, reducing, and fermentation accounted for 13.1% cumulatively. The study highlights the need for tailored waste management solutions based on regional challenges and successful practices. Promoting recycling infrastructure, composting, and waste reduction approaches are crucial to achieving sustainable waste management aligned with SDGs. Collaboration and knowledge-sharing between regions are essential to improve inefficient waste management mechanisms. Integrating the findings into policymaking and industry practices can lead to a more sustainable future with reduced environmental impact.
REVIEW | doi:10.20944/preprints202308.0916.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: chitin; fishery waste; microorganism; oligomers; polysaccharides
Online: 11 August 2023 (10:11:49 CEST)
COS production is carried out enzymatically using chitosanase, but this process is expensive. Production costs can be reduced by using crude enzyme chitosanase, and the resulting COS has depolymerization < 20 and molecular weight < 3900 Da. Sources of crude enzyme chitosanase come from the soil, sediment, and fishery waste. Chitosanase is produced from bacteria and molds isolated from the source or direct isolation process for extracellular enzymes, especially from fishery waste. Microorganisms in the soil produce chitosanase as a biocontrol and self-defense agent. Bacteria and molds have been isolated, including Bacillus cereus, Bacillus mycoides, Paenibacillus sp., and Penicillium janthinellum. Fishery waste, especially parts of the digestive tract, is a source of chitosanase because of its relation to its nature and food, such as small fish, frogs, and several types of crustaceans. In addition, fishery waste can be used as a carbon and nitrogen source (C/N) in microorganism culture media. The chitin content becomes a stimulant for the synthesis of chitosanase by microorganisms. Crude enzyme chitosanase has an active site that hydrolyzes chitosan by breaking glycosidic bonds and producing glucosamine units (GlcN) and N-acetyl glucosamine (GlcNAc). This mechanism can take place through two events, namely inverting and retaining. Crude enzyme chitosanase can break glycosidic bonds, especially with the same groups, for example, bonds between glucosamine or N-acetyl glucosamine. The COS produced is of the partially acetylated COS (paCOS) type, which still contains an acetyl group. The degree of deacetylation is a significant factor in the resulting COS product, COS with the fully deacetylated COS (fdCOS) type of chitosan with a high degree of deacetylation. Other factors to consider are the raw material of chitosan, the incubation time, the screening process, and the production of microorganism cultures.
ARTICLE | doi:10.20944/preprints202307.1466.v1
Subject: Engineering, Mechanical Engineering Keywords: Web-Based Application; Waste Management; Laravel
Online: 21 July 2023 (05:23:06 CEST)
Waste management is a significant issue that Indonesia must face. The presence of waste will always exist as long as life continues. One of the main challenges in waste management is the proper separation of organic and inorganic waste. As a solution to address this issue, the Ministry of Environment has made efforts to develop Waste Banks. However, it also creates new problems related to manual data collection, lack of monitoring by the community in implementing waste management activities, and a lack of specific reports regarding waste management conducted by officers. We propose the creation of a website using the Agile Development SDLC method. This website involve several steps and incorporate functions for data digitalization and expedited data collection, such as the addition of QR Code functionality, Monthly Reporting Function, and enhanced data security. The method used in this research is Agile Development. The application has been developed with a user-friendly interface and the latest web development technologies to ensure smooth performance. Overall, the web-based application for organic and inorganic waste using Laravel is an important step to promoting sustainable waste management practices.
ARTICLE | doi:10.20944/preprints202306.0761.v1
Subject: Engineering, Civil Engineering Keywords: Hazelnut shell; Agricultural waste; Concrete properties
Online: 12 June 2023 (04:52:51 CEST)
Concrete production requires a significant amount of natural resources, with aggregates comprising between 55% and 80% of the total volume. However, over-exploitation of natural aggregates has led to the exploration of alternative materials for use in concrete production. In this study, crushed hazelnut shells were investigated as a partial replacement for fine aggregate, addressing the problem of natural resource depletion and offering a second use for this important agricultural waste product available in Chile. Hazelnut shells were incorporated in percentages of 2.5%, 5%, and 10% by weight of sand for water-cement ratios of 0.4 and 0.5. The compressive strengths at 7 and 28 days and bending tensile strengths at 28 days were determined, alongside physical properties such as workability, temperature, air content, fresh density, and hardened density of the concrete. Our findings show that replacing 2.5% of the fine aggregate with hazelnut shells led to higher compressive strength at 28 days, exceeding the strength of the standard specimens by 9.5%, whereas replacing 5% of the fine aggregate led to the highest bending tensile strength, exceeding the resistance of the standard specimens by 3.5%. Moreover, the 0.4 w/c ratio consistently led to better results for both compressive and bending tensile resistances, with fewer and lower reductions in mechanical resistances compared to the standard mixture. Our results suggest that concrete mixes with hazelnut shells as a replacement for fine aggregate at a percentage of up to 2.5% can be used in constructive systems with compression strengths lower than 17 MPa, and mixtures with up to 10% hazelnut shell replacement can be used in structures with tensile bending stress requirements lower than 6 MPa. Overall, the use of hazelnut shells as a partial replacement for fine aggregate in concrete production presents an environmentally-friendly and cost-effective solution for the construction industry.
ARTICLE | doi:10.20944/preprints202305.0240.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Kitchen waste; Enzyme; Enzymatic hydrolysis; Biofertilizer
Online: 4 May 2023 (08:51:19 CEST)
The study addresses the management of kitchen waste by transforming it into biofertilizer formulations utilizing an effective in-house developed multi-enzyme preparation. A separate hydrolysis and fermentation bioprocessing approach which in particular relates to the application of a separate enzyme preparation from Aspergillus niger P-19 to separately hydrolyze kitchen waste, followed by the growth of Klebsiella pneumoniae AP-407 in the liquid hydrolysate as well with simultaneous production of carrier-based biofertilizer. In liquid and carrier-based biofertilizers, the viable cell count reaches 3.00 × 1012 CFU/ml and 3.00 × 1012 CFU/g, respectively. The current study adopts a novel process technique for the manufacturing of both carrier and liquid biofertilizers, adopting a zero-waste approach to the management of kitchen waste.
ARTICLE | doi:10.20944/preprints202207.0173.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Cement; Co-process; Waste; Incineration; Landfill
Online: 12 July 2022 (04:32:38 CEST)
Recently, the amount of waste generated has been rapidly increasing, there have been difficulties disposing of waste in Korea. As a solution to this, treating waste using a cement kiln has suggested, but the environmental and economic effects have not been specifically studied. In this study, the effects of alternative resources, and reducing the social costs(Installation and Operation) associated with waste treatment facilities were analyzed. Through a co-processing method, a reduction of approximately 53kg of CO2 can be realized during the production of one ton of cement, and cost savings of about 3,815 milion USD. Another effect is an extension of the expiration date for landfills by 7.55 years.
ARTICLE | doi:10.20944/preprints202206.0362.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: catalytic converters; waste gases; phosphating; oxidation
Online: 27 June 2022 (10:49:57 CEST)
Iron and chromium based alloys have found wide application in various fields of science and technology. Primary carrier based on Fe-Cr-Al alloy is used in block catalysts for high-temperature hydrocarbon conversion, in production of block metal catalysts for neutralization of toxic gases released during operation of internal combustion engines, as well as those present in smoke emissions from enterprises. Influence of thermal action on Fe-Cr-Al alloy foil and stability of secondary carrier on its surface was studied. Elemental composition of the surface layer of X15U5 alloy foil does not remain constant during heating and depends on the thermal treatment mode. Some of the elements come to surface and elemental composition of surface layer can differ significantly from that observed in the bulk of foil sample. This implies the possibility of changing the adhesive and adsorption properties of the foil surface, as well as the need to take this fact into account when supporting a secondary carrier and active phase to the foil. Applied technique of phosphating and supporting a secondary carrier to the foil surface makes it possible to obtain a sufficiently stable coating. There is no shedding of the secondary carrier from foil surface during high-temperature treatment in air.
ARTICLE | doi:10.20944/preprints202204.0282.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: bacteria; compost; organic waste; decomposition; inoculum
Online: 28 April 2022 (10:26:35 CEST)
Composting is one of the most economical and environmentally safe methods of recycling organic waste. Soil microorganisms play a significant role in decomposition and the availability of plant nutrients. This study was designed to prepare a suitable microbial inoculum and its evaluation on composting heap to decrease the time of waste degradation. The bacteria were isolated and molecular characterized from the soil near composting area by using 16S ribotyping technique. The identified strains of bacillus cereus used as an inoculum gives better results to expedite the degradation of organic waste. The prepared bacterial inoculum with molasses was also compared with commercial inoculum by optimizing physical and chemical parameters (temperature, oxygen, C: N, pH, and moisture content) of composting heap. Monthly reading of these parameters was taken from experimental and control treatments. The highest decomposition rate of organic waste was recorded in treatment A (experimental heap) where molasses and bacterial inoculum were added and less decomposition was observed in treatment D (experimental heap) where no inoculum and molasses were added. It was concluded from the studies that the prepared bacterial inoculum with two strains of Bacillus was effective and prepared mature compost in 2.5 months by increasing decomposition efficiency of organic waste. Furthermore, the prepared compost was also sustainable in its physical and chemical characteristic.
ARTICLE | doi:10.20944/preprints202110.0009.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Collagen; Environment; Fish Waste; Cytotoxic; Fermentation
Online: 1 October 2021 (11:37:42 CEST)
More than 800 million tons of fish are utilizing in a year and 25-30% become waste. The waste amount is beneficial source for extraction of collagen. But procedure of extraction is still to be optimized. The current study was designed to extract collagen from fish through fish waste fermentation under various conditions. For collagen extraction we did lactic acid fermentation in which yogurt and Dough bacteria was added with fish sample and placed it in incubator at 30ºC for one month. In yogurt and dough culture have at least 10 type of lactic acid bacterial species. After every week we check PH of each sample and take soup of that sample. After centrifugation of that sample’s TCA (Trichloroacetic acid) precipitation was done of yogurt and dough sample and kept at -20ºC. then did SDS-PAGE) using 6% resolving and 5% stacking gel of already stored sample. Then HaCaT cells (1 × 104 cells/well) were cultured in 96-well flat-bottom culture plates and treated with appropriate doses of FFCP (fermented fish collagen peptide) for 24 and 48 hours.The SDS-PAGE revealed that the collagen protein of fish had doublet pattern for α1 and α2 chains at corresponding to 145 kDa and 132 kDa respectively. The density for α1 twice as compared to α2. Our result agrees that The fish collagen consists mostly of α-chain as well as little amount of inter and intra molecular cross-linked components of α-chains; b (dimmer) and c (trimer). Different biochemical tests were done for identification of lactic acid bacteria catalase positive, citrate positive, urease negative. Our fermented fish collagen and peptides mixture were test for cellular cytotoxicity and proliferative effect on HaCaT cells. Current result shows that fermented extracted collagen are nontoxic and induce the proliferation of HaCaT cells. Current study is supported by various studies that revealed the medical application of fish extracted collagen as underline.
SHORT NOTE | doi:10.20944/preprints202106.0117.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: COVID-19; Medical Waste; Sustainability; Environment.
Online: 3 June 2021 (13:22:55 CEST)
The situation in the world of pandemics is rapidly changing, and the second wave of COVID-19 has put a lot of pressure on the government and private sector, which are primarily responsible for controlling the situation. COVID-19 positive cases have increased in recent months relative to last year, and the number of patients admitted to hospitals has also increased, despite the fact that few of them were denied admission due to shortage of beds. Normal people who experience any symptoms immediately isolate themselves and begin taking the COVID medications prescribed by medical personnel and their team. During these times, all domestic people tossed the wrappers and boxes of medicines into the regular trash can, and the waste was handed over to the waste collector, who treated it like any other domestic waste and disposed of it using open dumping or other methods. The goal of this perspective is to suggest the collections of these types of waste from domestics, and protect the natural resources like water, soil, and even living beings like animals from pollution (from the effect of SARS-CoV-2). The main challenge for environmental waste management agencies is determining who has COVID positive and which houses generate these types of waste; thus, proposed strategy may be beneficial to the long-term sustainability of natural resources and animals.
ARTICLE | doi:10.20944/preprints202012.0197.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Bioadsorbents; biodiesel; waste cooking oil; purification
Online: 8 December 2020 (10:03:26 CET)
The dry washing method is an alternative to replace water washing, thereby reducing the negative impacts of contamination. However, commercial adsorbents come from industrial processes that, due to their composition, may not be such a sustainable resource in the global biodiesel production process. In this study, the use of organic residues, such as sawdust, coconut fiber, nutshell, rice husk and water hyacinth fiber, were proposed as bioadsorbents for the purification of biodiesel from waste cooking oil (WCO). Quality parameters such as the acid value, water content, and free and total glycerin content were evaluated and compared with those of commercial resins such as Magnesol® and Amberlite™. Promising results were obtained using sawdust during the purification process, achieving a 31.6% reduction in the acid value compared to that of unpurified biodiesel, the reduction was 31.3% more efficient than Amberlite™. Sawdust adsorbed free glycerin at 55.8%, being more efficient than Amberlite™. The total glycerin values were similar between commercial resins and sawdust. A water content values were similar than Amberlite™ and better than that with Magnesol®, at 4.3% and 39.81%, respectively. These results show that sawdust can be used as an alternative bioadsorbent in a dry purification method for biodiesel being a residue with less environmental impact.
BRIEF REPORT | doi:10.20944/preprints202011.0320.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Bio hydrogen; photo-fermentation; agro-waste
Online: 10 November 2020 (15:05:24 CET)
This study evaluates the production of biohydrogen from agro industrial waste. The worldwide energy demand is increasing exponentially and the reserves of fossil fuels are depleting, the combustion of fossil fuels has the effect on environment because of CO2 emission. Hydrogen generation market size is forecast to cross 180 billion by 2024, according to a new research report by global market. For the production of biohydrogen. we had chosen groundnut shell as our source, using Tween80 as a surfactant we had undergone pre-treatment studies for (10min,20min,30min,40min,50min) we had estimated the content of cellulose, protein, carbohydrates at (1%,2%,3%,4%,5%) and obtained the optimum value in the form of graph. The production of hydrogen is done by using the rumen fluid of the cow and the quantity of the hydrogen produced by this process is identified by using the analytical instrument Gas Chromatography.
BRIEF REPORT | doi:10.20944/preprints202005.0355.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: microplastics; analysis; waste treatment; food; diet
Online: 23 May 2020 (04:58:22 CEST)
This preprint is focused in the presence of plastics and microplastics in food. We will discuss how many we eat, and how they arrive to the food, and why. We will treat many other things, such as the waste treatment in Europe and in Spain, with updated data; how much plastic waste is generated; what are microplastics and how they are analyzed, I will tell about the experience we have at the University of Alicante (UA); how they can be removed and we will estimate how many we eat over the course of a year.
ARTICLE | doi:10.20944/preprints202001.0057.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: biosorption; copper; algae; tailings; mine waste
Online: 8 January 2020 (03:06:34 CET)
Mining is one of the main economic activities of several developing countries as Chile. Due to the progressive fall of the ore grades and the increasingly refractory composition of minerals, concentrating plants have increased that has led to an increase in the generation of tailings. Tailings, especially those obtained in the past, have remaining copper and other valuable species in quantities that can potentially be recovered, such as gold, silver, vanadium and rare earth elements. This transforms this abundant waste into a potential source of precious or strategic metals for secondary mining. One of the techniques of solid-liquid separation that allows the processing of solutions with low concentrations of metals corresponds to the adsorption, and more recently the biosorption, which is based on the use of biological matrices that do not constitute an environmental liability after application. Biosorption occurs as a consequence of the wide variety of active functional groups present in the different types of biomass. Bacterial, fungal, plant and algal biomasses have been described as biosorbents, mainly for the treatment of diluted and simple solutions. This work aims to recover copper from leached tailings using biomass of the red algae Gracilaria chilensis as a biosorbent. The tailing samples were taken from an abandoned deposit in the north of Chile and after an acid leaching copper was biosorbed, for which the kinetics of adsorption and the equilibrium isotherms were studied, applying the Freundlich and Langmuir models. Operational parameters such as adsorbent dose, pH and initial metal concentration were studied.
ARTICLE | doi:10.20944/preprints201609.0012.v2
Subject: Environmental And Earth Sciences, Waste Management And Disposal Keywords: constraints; factors; household; solid waste management
Online: 9 September 2016 (07:42:15 CEST)
Solid waste management in Accra is a major challenge to the Metropolitan Authorities and inhabitants. The rapidly increasing population coupled with poor capacity of the municipal and private waste management companies to management waste effectively has created issues of environmental concern. Due to poor waste managements systems, most household dispose waste indiscriminately leading to floods and health issues. The study showed that about 60% of household waste is organic materials which has the potential to be converted to compost for agriculture purpose. Meanwhile plastics and rubbers which litters the environment as well as blocking major storm drains and gutters hence creating huge environmental hazard is made of 11% of the total component of most household waste generated daily. The study also revealed that among the methods of disposing waste, dumping waste in skip containers located at authorized places was the preferred means of disposing waste by household though others also dispose waste by other means such as burying and burning. Inadequate skip containers per population of household in an area coupled with irregularity of tracks picking these containers makes skip containers dumping site ugly scene, hence creating health issues. Among the constraints that impact negatively on sustainable waste management in Accra Metropolis, economic constraints was perceived as the main challenge which affect efficient waste management. Currently the country is going through serious economic challenges so government does not release money timely to fund projects which waste management is key. Most donor partners that use to support the government with funds have either reduced or redrawn their services as they have no confidence in the state of Ghana economy. Aside the constrains, the study also indicated that factors such as poor public attitude towards waste management, poor enforcement of sanitation by-laws, inadequate and untimely release of government funds were also seen as the main factors affecting waste management.