REVIEW | doi:10.20944/preprints201810.0178.v1
Subject: Biology, Plant Sciences Keywords: ornamental flowering plants; constructed wetlands; wastewater; pollutants
Online: 9 October 2018 (06:22:39 CEST)
The vegetation in constructed wetlands (CWs) plays an important role in wastewater treatment. Popularly, the common emergent plants in CWs have been vegetation of natural wetlands. However, there are ornamental flowering plants that have some physiological characteristics similar to the plants of natural wetlands that can stimulate the removal of pollutants in wastewater treatments; such importance in CWs is described here. A literature survey of 87 CWs from 21 countries showed that the four most commonly used flowering ornamental vegetation genera were Canna, Iris, Heliconia and Zantedeschia. In terms of geographical location, Canna spp. is commonly found in Asia, Zantedeschia spp. is frequent in Mexico (a country in North America), Iris is most commonly used in Asia, Europe and North America, and species of the Heliconia genus are commonly used in Asia and parts of the Americas (Mexico, Central and South America). This review also compares the use of ornamental plants versus natural wetland plants and systems without plants for removing pollutants (COD, BOD, nitrogen and phosphorous compounds). The removal efficiency was similar between flowering ornamental and natural wetland plants. However, pollutant removal was better when using ornamental plants than in unplanted CWs. The use of ornamental flowering plants in CWs is an excellent option, and efforts should be made to increase the adoption of these system types and use them in domiciliary, rural and urban areas.
CASE REPORT | doi:10.20944/preprints201608.0174.v1
Online: 18 August 2016 (10:36:09 CEST)
The ambient air quality data for particulate matter as well as criteria of gaseous pollutants were assembled during December 2013 to December 2015 from the Continuous Air Quality Monitoring Station (CAMS) located at Agrabad, Chittagong. The observation showed that during April- October, 24 hour average concentration of PM10 and PM2.5 were within the National Ambient Air Quality Standard (NAAQS) level but it increased occasionally by more than two and a half times during the whole non-monsoon period (November-March). The highest values found of PM2.5 were 321.1 µg/m3 in January, 2013 and 220.34 µg/m3 in December 2015. Whether, the highest alarming concentration of PM10 was reported as 474 µg/m3 in January 2007. The other gaseous pollutants such as SO2, NO2, O3, CO and Hydrocarbons remain well within the permissible limit except dry non-monsoon period. The yearly average increase of Air Quality Index (AQI) value indicates the growth rate of air pollution in Chittagong city. The main responsible pollutant for air pollution is found PM2.5.
ARTICLE | doi:10.20944/preprints202202.0129.v2
Subject: Chemistry, Applied Chemistry Keywords: biodegradation; pyrene; pollutants; bacteria; marine sponges; polluted seawater
Online: 22 April 2022 (03:32:48 CEST)
PAHs contaminants have toxic, carcinogenic, and even mutagenic properties. Screening bacteria from different sources capable of carrying out the biodegradation of PAHs is important for mapping and mobilization purposes and applying them to polluted hydrocarbon environments. The study aimed to compare the biodegradation power of two types of bacteria isolated from different sources against PAHs. The method applied is the interaction between bacterial suspen-sion and pyrene contaminated waste for 30 days. Biodegradation products in organic compounds were analyzed using GC/MS and FTIR. The analysis results found several indications of the performance of bacterial biodegradation, namely: the aggressiveness of biodegradation of Bl bacteria against pyrene was relatively more dominant than Sb bacteria. The percentage of to-tal bacterial biodegradation for product type Sb was (39.00 %), and that of the product of bacteri-al degradation type Bl (was 38.29 %). The biodegradation products of the test bacteria (Bl and Sb) were relatively similar to pyrene, in the form of alcohol and carboxylic acid organic com-pounds. It was concluded that there was no significant difference in biodegradation per-formance between Bl and Sb bacteria on for pyrene. Both types of bacterial isolates from differ-ent sources can carry out the function of biodegradation of pyrene.
ARTICLE | doi:10.20944/preprints202108.0113.v1
Subject: Earth Sciences, Atmospheric Science Keywords: computational fluid dynamics; OpenFOAM; docked vessel; gas pollutants
Online: 4 August 2021 (13:12:08 CEST)
Docked ships are a source of contamination for the city while they keep their engine working. Plumes emissions from large boats can carry a number of pollutants to the nearby cities causing a detrimental effect on the life quality and health of local citizens and ecosystems. A computational fluid dynamics model of the harbour area of Tromsø has been built in order to model the deposition of CO2 gas emitted by docked vessels within the city. The ground level distribution of the emitted gas has been obtained and the influence of the wind speed and direction, vessel chimney height, ambient temperature and exhaust gas temperature has been studied. The deposition range is found to be the largest when the wind speed is low. At high wind speeds, the deposition of pollutants along the wind direction is enhanced and spots of high pollutant concentration can be created. The simulation model is intended for the detailed study of the contamination in cities near the coast or an industrial pollutant source of any type of gas pollutants and can easily be extended for the study of particulate matter.
REVIEW | doi:10.20944/preprints202102.0337.v1
Subject: Materials Science, Biomaterials Keywords: Nanomaterials; Rare earth metals; Wastewater treatment; CNT; Pollutants
Online: 16 February 2021 (14:12:17 CET)
Today major environmental issue facing the universe is Industrial wastewater. They are present in the form of various pollutants like organic/inorganic, heavy metals, and non-disintegrating materials at an enormous amount. As of now, eliminating these pollutants from wastewater from industries in a viable manner has become a significant issue. Productive refinement methodologies are required to eliminate those toxins before removal. Furthermore, nanomaterials are innovationally powerful to purification of water by utilizing inexpensive nanofiltration and nano adsorbent. Heavy metal ions removal in an efficient way from the environment is the first and foremost problem from a biological and ecological perspective, and numerous research practices have been dedicated to the removal of harmful metal particles, involved both in the underground and surface wastewater. This article mainly focuses on the nanomaterials utilization of various contaminating materials removal from industrial wastewater with an exceptional spotlight on rare earth components and nanofiber and nanocomposite films. The objective is to offer references an outline in the field of developing nanomaterials utilization for harmful pollutants removal from industrial wastewater for industrializers and analysts.
ARTICLE | doi:10.20944/preprints201811.0306.v1
Subject: Earth Sciences, Environmental Sciences Keywords: coal; BTEX; hazardous air pollutants; domestic fuel burning
Online: 13 November 2018 (09:59:45 CET)
A D-grade type coal was burned under simulated domestic practices in a controlled laboratory set-up, in order to characterize emissions of volatile organic compounds (VOCs); viz. benzene, toluene, ethylbenzene and xylenes (BTEX). Near-field concentrations were collected in a shack-like structure constructed using corrugated iron, simulating a traditional house found in informal settlements in South Africa. Measurements were carried out using the Synspec Spectras GC955 real-time monitor over a three-hour burn cycle. The 3-hour average concentrations (in µg/m3) of benzene, toluene, ethylbenzene, p-xylene and o-xylene were 919 ± 44, 2051 ± 91, 3838 ±19, 4245 41 and 3576 ± 49, respectively. The cancer risk for adult males and females in a typical SA household exposure scenario, was found to be 1.1 -1.2 and 110-120 folds higher than the US EPA designated risk severity indicator (1E-6), respectively. All four TEX compounds recorded the Hazard Quotient (HQ) of less than 1, indicating a low risk of developing related non-carcinogenic health effects. The HQ for TEX ranged from 0.001– 0.05, with toluene concentrations being the lowest and ethylbenzene the highest. This study has demonstrated that domestic coal burning may be a significant source of BTEX emission exposure.
REVIEW | doi:10.20944/preprints201703.0014.v2
Subject: Earth Sciences, Environmental Sciences Keywords: PM10; TSP; pollutants; element markers; epidemiological; dispersion modeling
Online: 13 March 2017 (08:49:10 CET)
No doubt pollution is a global problem which must be holistically tackled. In doing this, adequate knowledge of the sources of pollution is important, therefore the aim of this paper is to review source apportionment with reference to top-down and bottom-up methods. In this paper, dispersion modeling, emissions inventory, and sampling methods were discussed. Also, analytical methods involved in top-down source apportionment were mentioned. The two techniques are needed to evaluate pollutants and their sources. Based on these two approaches, pollution control strategy would be developed and decisions can be made in deciding the right approach to solve or reduce the pollution problems.
ARTICLE | doi:10.20944/preprints202204.0205.v1
Subject: Chemistry, Other Keywords: pollutants; microplastics; heavy metals; PAH; pesticide residues; medical waste
Online: 21 April 2022 (10:53:10 CEST)
A quality marine ecosystem if it is free from GTP contaminants. Accuracy and caution are needed in the exploitation of marine resources as marine tourism destinations so that in the future, there will be no ecological hazards that cause chain effects, not only on aquatic ecosystems but also on humans. This article identifies exposure to GTP (MP, PAH, PR, HM, MW) in marine ecosystems in the MTA area and BCI waters. The combination of qualitative and quantitative analysis methods uses a combination of analytical instruments and mathematical formulas. The search results show the average total abundance of MP in seawater and fish samples (5.47 units/m3) and (7.03 units/m3), respectively, while in sediment and sponge samples (8.18 units/m3) and (8.32 units/m3). Based on the analysis of the polymer structure, it was identified that the dominant light group MP (PE, PP and PS), followed by PA and PC. Several PAH pollutants were identified in the samples, especially NL types found in all samples, followed by PN and AZ. BCI sea waters are suspected to be exposed to MW and PR. Pollutants of Pb+2 and Cu+2 around BCI were successfully calculated with average concentrations in seawater 0.164 mg/L and 0.294 mg/L, respectively, while in fish, 1.8110 µg/g and 2,452 µg/g, respectively. Based on these findings, the BCI area is not recommended as a marine tourism destination.
ARTICLE | doi:10.20944/preprints202109.0066.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: dyslipidemia; fetal programing; lipid metabolism; NAFLD; persistent organic pollutants
Online: 3 September 2021 (13:56:53 CEST)
Animal studies have shown that developmental exposures to polybrominated diphenyl ethers (PBDE) permanently affect blood/liver balance of lipids. No human study has evaluated associations between in utero exposures to persistent organic pollutants (POPs) and later life lipid metabolism. In this pilot, maternal plasma levels of PBDEs (BDE-47, BDE-99, BDE-100, and BDE-153) and polychlorinated biphenyls (PCB-138, PCB-153, and PCB-180) were determined at delivery in participants of GESTation and Environment (GESTE) cohort. Total cholesterol (TCh), triglycerides (TG), low and high density lipoproteins (LDL-C and HDL-C), total lipids (TL), and PBDEs were determined in serum of 147 children at ages 6-7. General linear regression was used to estimate the relationship between maternal POPs and child lipid levels with adjustment for potential confounders, and adjustment for childhood POPs. In utero BDE-99 was associated with lower childhood levels of TG (p=0.003), and non-significantly with HDL-C (p=0.06) and TL (p=0.07). Maternal PCB-138 was associated with lower childhood levels of TG (p=0.04), LDL-C (p=0.04), and TL (p=0.02). Our data indicate that in-utero exposures to POPs may be associated with long-lasting decrease in circulating lipids in children, suggesting increased lipid accumulation in the liver, a mechanism involved in NAFLD development, consistent with previously reported animal data.
ARTICLE | doi:10.20944/preprints201910.0043.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: telemedicine; carbon dioxide; air pollutants; vehicle emissions; primary care
Online: 4 October 2019 (10:25:37 CEST)
This retrospective study evaluates the effect of a telemedicine program developed in the central Catalan region in lowering the environmental footprint by reducing the emission of atmospheric pollutants thanks to a reduction in the number of hospital visits involving journeys by road. Between January 2018 and June 2019 a total of 12,322 referrals were made to telemedicine services in the primary care centers, avoiding a total of 9,034 face-to-face visits. In total, the distance saved was 192,682 km, with a total travel time savings of 3,779 hours and a total fuel reduction of 11,754 liters with an associated cost of €15,664. This represents an average reduction of 3,248.3 g of carbon dioxide, 4.05 g of carbon monoxide, 4.86 g of nitric oxide and 3.2 g of sulphur dioxide. This study confirms that telemedicine reduces the environmental impact of atmospheric pollutants emitted by vehicles, reducing the number of journeys made for face-to-face visits and can contribute to environmental sustainability.
Subject: Chemistry, Chemical Engineering Keywords: hypercrosslinked polymer; p-hydroxy-phthalic acid; pollutants; adsorption; biodegradation
Online: 17 September 2019 (11:36:51 CEST)
Adsorption is an effective strategy for the removal of pollutants from the wastewater. Herein, a 2-hydroxyterephthalic acid (HTC) modified hypercrosslinked polymer (HTC-HCP) is successfully synthesized via Friedel-Crafts reactions, and used as an adsorbent for the different types of pollutants including organic contaminants and heavy metal ions from wastewater. Excellent adsorption capacities are observed for amines (aniline, p-methylaniline (p-MA), p-chloroaniline (p-CA), and p-aminobenzoic acid (p-ABA)), phenols (phenol, p-chlorophenol (4-CP) Bisphenol A (BPA), 1-Naphthol (1-NP)), dyes (rhodamine B (RhB) and methyl orange (MO)), and metal ions (Pb2+, Hg2+, and Cd2+). The resulting polymers exhibited excellent adsorption performance towards these pollutants. Especially, the removal rate of aniline is above 95% in the concentration of 2.5 mg/L in 40 min at 25 °C. The interaction mechanism has been investigated, and confirmed by FTIR and the theoretical calculation results. It is due to surface complexation and chemisorption between adsorbent and adsorbate. The polymer exhibits good performance such as high adsorption capacity, high separation efficiency, biodegradable properties, and easy regeneration, suggesting that its potential technological applications for the removal of organic compounds and heavy metal ions from actual industrial effluent.
REVIEW | doi:10.20944/preprints201807.0370.v1
Subject: Biology, Other Keywords: organic farming; persistent organic pollutants; crops; peasant farmers; education
Online: 20 July 2018 (04:09:42 CEST)
Organic farming products are fast gaining acceptance from consumers all over the world due to the perceived belief that they are safe for human consumption. In recent years, there has been an increase in the levels of persistent organic and inorganic pollutants in the environment. These pollutants may be found in materials such as sewage sludge, treated wastewater, farmyard manure (human and animal feaces and urine) that are used for organic farming. The present review examined through literature the presence of these emerging pollutants in crops that are cultivated from farming activities practicing organic farming. The review highlighted and documented various pollutants that may be found in crops due to non-compliance with legislation establishing organic farming. The need to develop a robust method for identifying safe products from organic farming was highlighted. The impact of non-compliance and lack of proper education on the peasant farmers practicing backyard farming was also enumerated.
ARTICLE | doi:10.20944/preprints201703.0032.v1
Subject: Chemistry, Applied Chemistry Keywords: organic pollutants; enzymatic remediation; sulforhodamine B; soybean peroxidase; chloroperoxidase
Online: 6 March 2017 (07:45:32 CET)
Enzymatic degradation of organic pollutants is a new and promising remediation approach. Peroxidases are one of the most commonly used classes of enzymes to degrade organic pollutants. However, it is generally assumed that all peroxidases behave similarly and produce similar degradation products. In this study, we conducted detailed studies of the degradation of a model aromatic pollutant, Sulforhodamine B dye (SRB dye), using two peroxidases—soybean peroxidase (SBP) and chloroperoxidase (CPO). Our results show that these two related enzymes had different optimum conditions (pH, temperature, H2O2 concentration...etc.) for efficiently degrading SRB dye. High-performance liquid chromatography and LC-mass spectrometry analyses confirmed that both SBP and CPO transformed the SRB dye into low molecular weight intermediates. While most of the intermediates produced by the two enzymes were the same, the CPO treatment produced at least one different intermediate. Furthermore, toxicological evaluation using lettuce (Lactuca sativa) seeds demonstrated that the SBP-based treatment was able to eliminate the phytotoxicity of SRB dye, but the CPO-based treatment did not. Our results show, for the first time, that while both of these related enzymes can be used to efficiently degrade organic pollutants, they have different optimum reaction conditions and may not be equally efficient in detoxification of organic pollutants.
REVIEW | doi:10.20944/preprints202206.0014.v1
Subject: Life Sciences, Other Keywords: pharmaceutical toxicants; recalcitrant pollutants; co-metabolic pathways; biostimulation; bioaug-mentation
Online: 1 June 2022 (10:29:47 CEST)
Pharmaceutically active compounds and organic pollutants are becoming a major environmental dispute possessing serious threat to the water bodies and terrestrial ecosystem. Microorganisms are capable of the self-purification process, and hence the microbial degradation is considered a lucrative method to counteract the therapeutic and recalcitrant pollutants. Pharmaceutical toxicants in aquatic system can be treated by conventional wastewater treatment, but slow sludge settling, presence of mixture of pharmaceuticals and recalcitrant compounds often pose a potential ecological risk. Some microbial strains are very effective in reducing the chemical oxygen demand (COD), biological oxygen demand (BOD), total dissolved solids (TDS), and turbidity in pharmaceutical industrial wastewater treatment. The natural microbial community has a significant role in the ecological processes of pharmaceutical and organic compounds, including non-steroidal anti-inflammatory drugs, analgesics, blood lipid regulators and other micropollutants. Specific bacterial isolates can act as biodegraders, and fungal treatment could offer protection to the ecosystem. These microorganisms use the pollutants as their sole carbon source and transform the contaminants by co-metabolic pathways. Natural attenuation by native microorganisms, biostimulation and bioaugmentation are the processes employed to degrade the target contaminant. Microorganisms may also be genetically engineered to improve the neutralization efficiency, which would assist in the mineralization of the pollutants. Thus, employing microorganisms to detoxify the pollutants probably enhances the sustainable potential biodegradability, improves water quality standards and ensures eco-friendly alternative bioremediation strategy.
ARTICLE | doi:10.20944/preprints202201.0355.v1
Subject: Chemistry, Applied Chemistry Keywords: Wastewater treatment; Nitrogen-containing pollutants; Nitrate photoreduction; SCR; Photocatalysis; Titania.
Online: 24 January 2022 (12:46:10 CET)
Bare titania and metal promoted TiO2 catalysts were employed in the treatment of nitrates, which are ubiquitous pollutants of wastewater. The results show that the process can be carried out under visible light (from white light LED lamp) and, in the best case, 23.5% conversion of nitrate was obtained over 4 hours with full selectivity towards N2 by employing 0.1 mol% Ag/TiO2 prepared by flame spray pyrolysis. Moreover, the performance was worse when testing the same catalysts with tap water (11.3% conversion), due to the more complex composition of the matrix. At last, it was found that the photoreduction of nitrate can be effectively performed in combina-tion with the photo-oxidation of ammonium without loss in the activity, opening to the possi-bility to treat highly polluted wastewater with a single process. The latter treatment employs the two contaminants simultaneously as electron and holes scavengers, with very good selectiv-ity, in a completely new process that we may call Photo-Selective Catalytic Reduction (Pho-to-SCR).
ARTICLE | doi:10.20944/preprints202112.0006.v1
Subject: Engineering, Other Keywords: Agricultural Tractor; Diesel Emission; Air Pollutants; Emission Inventory; Geographic Information System
Online: 1 December 2021 (10:36:45 CET)
Due to the shortage of agricultural labor forces and rapid aging of farmers, the utilization of tractors is becoming popular and essential in Korea. Tractors can be classified into two types, a walking tractor called as a power tiller and a riding tractor. In this study, agricultural tractors including walking and riding types were categorized into 4 levels by rated output power. And diesel emission inventory of tractors was established and analyzed using 2011 and 2019 survey data in Korea. Emission inventory including CO, NOx, SOx, TSP(PM10), PM2.5, VOCs and NH3 were established using Tier 3 methodology. The total amount of emission using agricultural tractors was decreased about 13% from 2011 to 2019. The number of walking tractors were decreased by about 19% in 8 years, on the other hand that of riding tractors were increased by about 12%. However, the emission reduction is about 48% for walking tractors and the emission increment is about 5% for riding tractors. Thus, the total emission from agricultural tractors was decreased by about 16% in those periods. It is due to the decrease of 21% and 15% in the hours of use of walking and riding tractors, respectively, in 2019. Walking tractors mainly emit air pollutants from spraying and transporting. Riding tractors mainly 61% of total air pollutants emits from soil preparation and transporting operations. Geographic information system (GIS) was used to spatially assign air pollutants variables into 17 provinces and metropolitan cities in Korea. High emission generating regions and changes of emissions during 8 years were clearly seen in GIS analysis. High air pollutant emitting regions are mainly located in the western and southern regions of Korea, which have plenty of arable areas compared to other regions in Korea.
REVIEW | doi:10.20944/preprints201909.0020.v1
Subject: Chemistry, Analytical Chemistry Keywords: chemical pollutants; chemometrics; constructed wetlands; hydroponics; macrophytes; models; toxicity; water pollution
Online: 2 September 2019 (09:45:46 CEST)
Heavy metals and organic pollutants are ubiquitous environmental pollutants affecting the quality of soil, water and air. Over the past 5 decades, many strategies have been developed for the remediation of polluted water. Strategies involving aquatic plant use are preferable to conventional methods. In this study, an attempt was made to provide a brief review on recent progresses in research and practical applications of phytoremediation for water resources with the following objectives: (1) to discuss the toxicity of toxic chemicals pollution in water to plant, animals and human health (2) to summarise the physicochemical factors affecting removal of toxic chemicals such as heavy metals and organic contaminants in aqueous solutions by aquatic plants; (3) to summarise and compare the removal rates of heavy metals and organic contaminants in aqueous solutions by diverse aquatic plants; and (4) to summarise chemometric models for testing aquatic plant performance. More than 20 aquatic plants specie have been used extensively while duckweed (L. minor), water hyacinth (Eichhornia crassipes), water lettuce (P. stratiotes) are the most common. Overall, chemometrics for performance assessment reported include: Growth rate (GR), Growth rate inhibition (% Inhibition), Metal uptake (MU), translocation/transfer factor (TF), bioconcentration factor (BCF), Percent metal uptake (% MU), Removal capacity (RC) and Tolerance index (TI) while absorption rate have been studied using the sorption kinetics and isotherms models such as pseudo-first-order (PFO), pseudo-second-order (PSO), Freundlich, Langmuir and Temkin. Using modeling and interpretation of adsorption isotherms for performance assessment is particularly good and increases level of accuracy obtained from adsorption processes of contaminant on plant. Conclusion was drawn by highlighting the gap in knowledge and suggesting key future areas of research for scientists and policymakers.
COMMUNICATION | doi:10.20944/preprints201611.0127.v1
Subject: Earth Sciences, Environmental Sciences Keywords: persistent organic pollutants, bioavailability, Diffusive Gradient Thin film (DGT), passive probe, degradation
Online: 25 November 2016 (09:59:08 CET)
The present study describes the activities performed to test a new method for measuring the mobility of polycyclic aromatic hydrocarbons (PAHs) in the solid phase of sediments within the context of environmental pollution risk assessment. The method is based on the design of a new configuration (new materials) of the commercial passive sampler Chemcatcher as probe for predicting the bioavailability of persistent organic pollutants in marine sediments (or in water saturated soils).
ARTICLE | doi:10.20944/preprints201808.0176.v1
Subject: Earth Sciences, Environmental Sciences Keywords: persistent pollutants; risk assessment; arctic; glacial melt; climate change; human health; alaska; alpine glacier; Alaska Range
Online: 9 August 2018 (00:40:50 CEST)
To assess the presence of organochlorine pollutants (OCP) in Alaskan sub-Arctic latitudes, we analyzed ice core and meltwater samples from Jarvis Glacier, a polythermal glacier in Interior Alaska. Jarvis Glacier is receding as atmospheric warming continues throughout the region, increasing opportunity for OCP transport both englacially and into the proglacial watershed. Across all meltwater and ice core samples we identify the pesticides DDT, DDE and DDD, α- HCH and ϒ-HCH. OCP concentrations in ice core samples were highest at the 7-14 m depth (0.51 ng/L of DDT) and decreased gradually approaching the bedrock at 79m. Meltwater concentrations from the proglacial creek slightly exceeded concentrations found in the ice core, potentially indicating aggregate OCP glacial loss, with peak OCP concentration (1.12 ng/L of DDD) taken in July and potentially associated to peak melt. Ongoing use of DDT to fight Malaria in Asia, and the extended atmospheric range of HCH may account for concentrations in near-surface ice, correlating with use and atmospheric transport. The opportunity for biota bioaccumulation of OCPs, or human uptake of OCPs from glacial meltwater, may increase as glacial melt continues.
ARTICLE | doi:10.20944/preprints202106.0353.v1
Subject: Engineering, Automotive Engineering Keywords: Hazardous air pollutants; Medium-duty diesel trucks; Driving cycles; Non-methane volatile compound; Aldehydes; Polycyclic aromatic hydrocarbons
Online: 14 June 2021 (11:38:40 CEST)
Studies on the characteristics of hazardous air pollutants (HAPs) in the emissions of medium-duty diesel trucks are significantly insufficient compared to that on heavy-duty trucks. This study investigates the characteristics of regulated pollutants and HAPs such as volatile organic compounds (VOCs), aldehydes, and polycyclic aromatic hydrocarbons (PAHs), and estimates non-methane hydrocarbon (NMHC) speciation in the emissions of medium-duty diesel trucks. Ten medium-duty diesel trucks conforming to Euros 5 and 6 were tested for worldwide harmonized light duty driving test cycle (WLTC), new European driving cycle (NEDC), constant volume sampler (CVS)-75, and National Institute of Environmental Research (NIER)-9 using a chassis dynamometer. CO and NMHC emissions were the highest in the NEDC because of its longer low-speed driving time. NOx emissions were the highest in WLTC owing to the influence of thermal NOx in the high-speed phase. Alkanes dominated non-methane volatile compound (NMVOC) emissions owing to the low reaction of the diesel oxidation catalyst. After-treatment system, driving, and engine conditions influenced the individual components of NMVOC emissions. Formaldehyde emissions were the highest among aldehydes irrespective of driving cycles. By sampling the particle-phase of PAHs, we detected benzo(k)fluoranthene and benzo(a)pyrene and estimated the concentrations of the gas-phase PAHs with models to obtain the total PAH concentrations. The toxic equivalency quantities of benzo(k)fluoranthene and benzo(a)pyrene from NIER-9 (cold) for both Euro 5 and Euro 6 vehicles were more than five times higher than that of NIER (hot) and NEDC. In the case of NMHC speciation, formaldehyde emissions were the highest in all the driving cycles. Formaldehyde and benzene must be controlled in the emissions of medium-duty diesel trucks to reduce their health threats. The results of this study will aid in establishing a national emission inventory system for HAPs of mobile sources in Korea.
Subject: Keywords: air pollutants/exposomics; autoimmunity; autophagy; cancers; COPD; environmental diseases; eQTL; infection; inflammatory; polymorphism; prognosis; risk; susceptibility; theragnosis
Online: 4 June 2020 (06:20:15 CEST)
The rising incidence of complex illnesses and their costs have revolutionized basic research, patient management, and societal needs. Between 70 to 90% of the risk of developing a disease is due to the air we breathe, the water we drink, and the surroundings in which we work and live. Visibly polluted, infectious or not, the fact remains that we are more than ever exposed to environmental risks. Air pollution is the fourth most prevalent deadly risk factor worldwide and by far the leading risk factor for hundreds of diseases, including respiratory infections, inflammatory illness, and cancer. Thus, an unhealthy environment can be considered as a pandemic, affecting 280 million people and claiming 12 million deaths every year. Although critical for identifying of the people at risk, the causal environment components (pollutants and/or the microbiome), and the affected physiological mechanisms are not well understood. Herein, we consider the dysregulation of macroautophagy (hereafter referred to as ‘autophagy’), as the mechanism at the heart of an immediate response to environmental stress. We discuss the missing link between the autophagy gene variations, and the exposome in the susceptibility, prognosis, and management of complex diseases when embracing personalized medicine.
ARTICLE | doi:10.20944/preprints201909.0281.v1
Subject: Chemistry, Analytical Chemistry Keywords: polymer-derived contaminants; pvc fires; fire emissions analysis; polymer leachate characterization; gc-ms and ftir analysis of gaseous pollutants
Online: 25 September 2019 (09:12:03 CEST)
In order to assess the human exposure risks from the release of contaminants from water pipes made of polyvinyl chloride (PVC), experiments were carried out by subjecting the PVC pipe material to burning and leaching conditions followed by analysis of the emission and leachate samples. The emissions of burning pipes were analyzed by both infrared spectrometry and gas chromatography-mass spectrometry (GC-MS). The emission results indicate the presence of chlorinated components including chlorine dioxide, methyl chloride, methylene chloride, allyl chloride, vinyl chloride, ethyl chloride, 1-chlorobutane, tetrachloroethylene, chlorobenzene, and hydrogen chloride were detected in the emissions of burning PVC pipes. Furthermore, the concentrations of benzene, 1,3-butadiene, methyl methacrylate, carbon monoxide, acrolein, and formaldehyde were found at levels capable of affecting human health adversely. The analysis of PVC pipe leachates using GC-MS shows that there are 40-60 tentatively identified compounds, mostly long-chain hydrocarbons such as tetradecane, hexadecane, octadecane, and docosane, were released when the burned PVC materials were soaked in deionized water for one week. Quantitative analysis shows that 2-butoxyethanol, 2-ethyl-1-hexanol, and diethyl phthalate were found in the burned PVC polymer at the average levels of 2.7, 14.0, and 3.1 micrograms per gram (g/g) of pipe material. This study has significant implications for understanding the benzene contamination of drinking water in the aftermath of wildfires that burned polymer pipes in California.
ARTICLE | doi:10.20944/preprints201703.0176.v2
Subject: Chemistry, Analytical Chemistry Keywords: Fabric Phase Sorptive Extraction (FPSE); Polycyclic Aromatic Hydrocarbons (PAHs); Persistent pollutants; Green Analytical Chemistry (GAC); Environmental water; Sorptive microextraction
Online: 19 April 2017 (19:27:27 CEST)
Fabric phase sorptive extraction (FPSE) combines the advanced material properties of sol–gel derived microextraction sorbents and the flexible and permeable fabric support to create a robust, simple and green sample preparation device. It simultaneously improves the extraction sensitivity, and the speed of the extraction by incorporating high volume of sponge-like porous sol–gel hybrid inorganic–organic sorbents into permeable fabric substrates that is capable of extracting target analytes directly from simple to complex aqueous sample matrices. For the first time, this technique was applied to the trace level determination of selected polycyclic aromatic hydrocarbons (PAHs) in environmental water samples using a non-polar sol–gel C18 coated FPSE media. Several extraction parameters were optimized to improve extraction efficiency and to achieve high detection sensitivity. Validation tests of spiked samples showed good linearity for four selected PAHs (R2 = 0.9983–0.9997) over a wide range of concentrations (0.010-10 ng/mL). Limits of detection (LODs) and quantification (LOQs) were measured at pg/mL levels, 0.1–1 pg/mL and 0.3–3 pg/mL, respectively. Inter- and intra-day precision tests showed variations of 1.1–4.1% for four selected PAHs. Average absolute recovery values were in the range of 88.1–90.5% surpassed the recovery prediction model, with relative standard deviations below 5%. The developed FPSE-HPLC-FLD protocol was finally applied to analyze 8 environmental water samples. Out of four selected PAHs, fluoranthene (Flu) and phenanthrene (Phen) were the most frequently detected in four samples, at concentration levels of 5.6–7.7 ng/mL and 4.1-11 ng/mL, respectively followed by anthracene (Anth) and pyrene (Pyr) in two samples. The newly developed FPSE-HPLC-FLD protocol is simple, green, fast and economical, with adequate sensitivity for trace levels of four selected PAHs and seems to be promising in routine monitoring of water quality and safety.