CASE REPORT | doi:10.20944/preprints201806.0465.v1
Online: 28 June 2018 (11:12:33 CEST)
A E. Crassipes is considered a problem in different aquatic ecosystems, due to its abundance could become a solution to design and build economic and efficient treatment plants, and especially for the production of biofuels such as bioethanol. The objective of this research is to design and implement a sustainable development process between phytoremediation and bioethanol production with E. crassipes, evaluating the incidence of chromium adhered to the biomass of this plant in the production of bioethanol. Materials and methods: A system was installed to evaluate the phytoremediation with E crassipes with water loaded with chromium, determining the effectiveness of this plant to remove this heavy metal even if it is alive in a body of water. After this process, we proceeded to bring the biomass loaded with chromium to bioreactors to evaluate the production of bioethanol, assessing three types of biomass, one without chromium adhered and the other two with chromium adhered to its plant structure. There was an impact of the ethanol production of the E crassipes due to the presence of chromium, but this production can be taken into account for the assembly of an integral system of phytoremediation and bioethanol production, making the most of this biomass.
ARTICLE | doi:10.20944/preprints202102.0290.v1
Subject: Biology, Anatomy & Morphology Keywords: abiotic stress; strawberry; companion plants; phytoremediation
Online: 11 February 2021 (19:00:26 CET)
Strawberry is a saline sensitive plant adversely affected under slightly or moderately saline conditions. Growth and biochemical parameters of strawberry plants grown under NaCl (0-, 30-, 60-, and 90 mmol L-1) conditions with or without a halophytic companion plant (Portulaca oleracea L.) were investigated in a pot experiment. Salt stress negatively affected the growth, physiological (stomatal conductance, electrolyte leakage, total soluble solids) and biochemical parameters such as chlorophyll contents (chl-a and chl-b), proline, hydrogen peroxide, malondialdehyde, catalase, and peroxidase enzyme activities, lycopene, vitamin C contents along with the mineral uptake of strawberry plants. The companionship of P. oleacea increased fresh weight, dry weight, and fruit average weight and total fruit yield of strawberry plants along with the improvement of physiological and biochemical parameters. This study showed that cultivating of P. oleracea with strawberry plants under salt stress conditions effectively increased strawberry fruit yield and quality. We, therefore, that approaches towards the use of P. oleracea could be an environmentally friendly method that should be commonly practised where salinity is of great concern.
ARTICLE | doi:10.20944/preprints202006.0108.v1
Subject: Chemistry, Organic Chemistry Keywords: Chlorella vulgaris; biodiesel; phytoremediation; molecular networking; pigments
Online: 7 June 2020 (16:36:23 CEST)
The commercial cultivation of microalgae began in the 1960s and Chlorella was one of the first target organisms. The species has long been considered a potential source of renewable energy, an alternative for phytoremediation, and more recently, as a growth and immune stimulant. However, Chlorella vulgaris, which is one of the most studied microalga, has never been comprehensively profiled chemically. In the present study, comprehensive profiling of the Chlorella vulgaris metabolome grown under normal culture conditions was carried out, employing tandem LC-MS/MS to profile the ethanolic extract and GC-MS for fatty acid analysis. The fatty acid profile of C. vulgaris was shown to be rich in omega-6, -7, -9, and -13 fatty acids, with omega-6 being the highest, representing more than sixty percent (>60%) of the total fatty acids. This is a clear indication that this species of Chlorella could serve as a good source of nutrition when incorporated in diets. The profile also showed that the main fatty acid composition was that of C16-C18 (>92%), suggesting that it might be a potential candidate for biodiesel production. LC-MS/MS analysis revealed carotenoid constituents comprising violaxanthin, neoxanthin, lutein, β-carotene, vulgaxanthin I, astaxanthin, and antheraxanthin, along with other pigments such as the chlorophylls. In addition to these, amino acids, vitamins, and simple sugars were also profiled, and through mass spectrometry-based molecular networking, 48 phospholipids were putatively identified.
ARTICLE | doi:10.20944/preprints201810.0007.v1
Subject: Engineering, Other Keywords: benzotriazole; biofilter; bioretention; green infrastructure; phytoremediation; sorption; stormwater
Online: 1 October 2018 (11:55:42 CEST)
Urban stormwater runoff is a significant source of pollutants into surface water bodies. One such pollutant, 1H-benzotriazole, is a persistent, recalcitrant trace organic contaminant commonly used as a corrosion inhibitor in airplane deicing processes, automobile liquids, and engine coolants. This study explored the removal of 1H-benzotriazole from stormwater using bench-scale biofilter mesocosms planted with California native sedge, Carex praegracilis, over a series of three storm events and monitoring period. Benzotriazole metabolites glycosylated benzotriazole and benzotriazole alanine were detected and benzotriazole and glycosylated benzotriazole partitioning in the system were quantified. With a treatment length of seven days, 97.1% of benzotriazole was removed from stormwater effluent from vegetated biofilter mesocosms. Significant concentrations of benzotriazole and glycosylated benzotriazole were observed in the C. praegracilis leaf and root tissue. Additionally, a significant missing sink of benzotriazole developed in the vegetated biofilter mesocosms. This study suggests that vegetation may increase the operating lifespan of bioretention basins by enhancing degradation of dissolved trace organic contaminants, thus increasing the sorption capacity of the geomedia.
ARTICLE | doi:10.20944/preprints201612.0014.v1
Subject: Earth Sciences, Environmental Sciences Keywords: sustainable technology; phytoremediation; germination; Bouteloua dactyloides; Cynodon dactylon
Online: 2 December 2016 (08:55:14 CET)
Mining wastes generate a high environmental impact, and population exposure to metals and metalloids. Phytoremediation is a technology that uses plants to remediate polluted sites, one of its limitations is seed germination in soil with high content of metals and metalloids. B. dactyloides is a native specie from semiarid regions, while C. dactylon is an introduced specie, both are tolerant to drought and low temperatures. Owing, the objective of this research was to evaluate the germination of both species, exposed to a multi-polluted soil with As, Cd, Pb and Zn of a mining site, pondering different pH conditions (from 5.0 to 9.0). The study considered 4 repetitions by type of seed and soil pH. B. dactyloides showed higher germination percentage (83%) with pH 7.8; while the greater germination of C. dactylon was 34 % at pH 6.0. In the soil at pH 5, the germination in both species was not reached, owing that metals are more bioavailable in an acid environment. C. dactylon is less tolerant to As, Cd, Pb and Zn, so it is considered not effective for phytoremediation process. B. dactyloides has a high phytoremediation potential for multi-polluted sites, but further experiments are needed.
ARTICLE | doi:10.20944/preprints202112.0152.v1
Subject: Engineering, Civil Engineering Keywords: air pollution; particulate matter; WAI; urban trees; children health; phytoremediation
Online: 9 December 2021 (12:00:05 CET)
Air pollution is now considered to be the world’s largest environmental health threat accounting for millions of deaths globally each year. The social group that is particularly exposed to the harmful effects of air pollution is the children. A daily route to school can constitute an important component of children’s physical activity, but air pollution can pose a threat to their health. Numerous studies have proved high loads of PM can be effectively reduced by vegetation. Little is however known, whether vegetation can also reduce PM during the leaf dormancy period. In this study, we investigated the role of trees in PM removal on children’s routes to schools during winter. We investigated walking routes to selected schools in Warsaw, by examining the adjacent vegetation and PM2.5 and PM10 concentrations and the presence of local black-smoke-belching stoves. We found that proximity to local CHP emitters had the strongest impact on pollution on the way to schools, while not finding a significant relationship between dense greenery and PM loads. Even more, the highest density of vegetation along walking routes tended to stimulate higher PM concentrations. The results obtained show the poor performance of tree canopy in reducing PM loads during winter.
ARTICLE | doi:10.20944/preprints202211.0375.v1
Subject: Biology, Ecology Keywords: Cr stress; rhizosphere bacterial community; Iris tectorum; 16S rRNA sequencing technology; Phytoremediation
Online: 21 November 2022 (06:27:02 CET)
With the rapid development of industry, Cr has become one of the major heavy metal pollutants in soil, which has caused serious effects on the soil's ecological environment. However, the effects of Cr stress on bacterial communities in plant rhizosphere soils remain unclear. In this study, I. tectorum was selected as the research object, and 16S rRNA high-throughput sequencing technology was used to analyze the effects of Cr stress on the structure and diversity of the bacterial community in the rhizosphere soil of I. tectorum. The results showed that I. tectorum had strong tolerance and enrichment to Cr. However, under Cr stress, the diversity and abundance index of rhizosphere bacteria decreased by 8.5% and 6.8% on average, and the Sobs index decreased by 7.6%. Moreover, the bacterial community changed by 20.1% due to the addition of Cr, further leading to a 15.9% decrease in the common species of the bacterial community, among which Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteriota accounted for more than 74.8% of the total sequence. According to the symbiosis network diagram, it was found that under a two-cultivated pattern, the synergizing effect between dominant bacteria was significantly enhanced, and the soil microenvironment was improved. Redundancy analysis showed that C, N, and P nutrient elements and Cr contents in uncontaminated and contaminated soils were the primary driving factors for the succession of I. tectorum rhizosphere bacterial community, and the response was stronger after Cr(Ⅵ) was added. In conclusion, the results of this study will provide insights into the response of rhizosphere bacterial communities to heavy metal Cr and the interactions between wetland plants and rhizosphere bacteria in wetland phytoremediation.Keywords: Cr stress; rhizosphere bacterial community; Iris tectorum; 16S rRNA sequencing technology; Phytoremediation
ARTICLE | doi:10.20944/preprints202012.0816.v1
Subject: Engineering, Automotive Engineering Keywords: heavy metals; industrial wastewater; natural wetlands; phytoremediation; Wadi Zomer restoration; water quality
Online: 31 December 2020 (13:46:33 CET)
This paper investigated the effectiveness of natural wetlands (Phragmites australis) along Wadi Zomer in reducing the organic and inorganic pollution loads from diverse industrial discharges including occasional emergency discharges from Nablus West Sewage Treatment Plant (NWSTP), Palestine. We monitored physical and chemical parameters at four selective sampling stations (S1-S4) along Wadi Zomer with a length of 5 km downstream of NWSTP to assess the purification capacity of Wadi Zomer treatment wetlands (water, sediment, and vegetation) with Phragmites australis in pollution loads reduction. The results showed that S2 (0+0.5 km) and S3 (0+3.0 km) reflected an increase in pollution loads due to illicit industrial discharge and sewer overflow discharge from NWSTP during emergency conditions. BOD values varied significantly along the sampling sites from 6.64 mg/l (S1) to 437.10 mg/l (S3). The BOD at S1 and S2 in water samples were below the Palestinian Water Standard (PWS) compared to S3 and S4 with 437.1 and 333.9 mg/l, respectively. Water samples from all sites (S1-S4) showed a decreasing tendency in heavy metals concentrations (Fe>Cu>Zn>Cr >Ni) and were below the PWS limits, sediment samples followed the same decrease pattern for Zn, Cr, and Ni content with Wadi Zomer flow course. The concentration of Fe (6687 mg/kg) and Cu (1384.7 mg/kg) were highest in the sediment samples (S1-S4); this might be due to non-point sources of pollution. The research demonstrated that phytoremediation is a sustainable nature-based technology for the restoration of heavily polluted surface water bodies in Palestine.
ARTICLE | doi:10.20944/preprints202107.0344.v1
Subject: Biology, Anatomy & Morphology Keywords: Phytoremediation; Petroleum hydrocarbon-degrading bacteria; Salix; Eleocharis; Alkanes; Polycyclic aromatic hydrocarbons; Plant growth promoting rhizobacteria
Online: 15 July 2021 (09:27:25 CEST)
Phytoremediation, a method of phytomanagement using the plant holobiont to clean up polluted soils, is particularly effective for degrading organic pollutants, such as alkanes and polycyclic aromatic hydrocarbons (PAHS). However, the respective contributions of host plants and their associated microbiota within the holobiont to the efficiency of phytoremediation is poorly understood. Identification of plant-associated bacteria capable of efficiently utilizing these compounds as carbon source while stimulating plant-growth, is a keystone for phytomanagement engineering in order to improve the efficiency of pollutant removal. In this study, we sampled the rhizosphere and the surrounding bulk soil of Salix purpurea and Eleocharis obusta from the site of a former petrochemical plant in Varennes, QC, Canada. Our objectives were to: (i) isolate and identify indigenous bacteria inhabiting these biotopes; (ii) assess the ability of isolated bacteria to utilize alkanes (dodecane and hexadecane) and PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and (iii) determine the plant growth-promoting (PGP) potential of the isolates using five key traits. A total of 438 morphologically different bacterial isolates were obtained, purified, preserved and identified through PCR and 16S rRNA gene sequencing. Identified isolates represent 62 genera, including taxa such as Acinetobacter, Arthrobacter, Bacillus, Enterobacter, Nocardia, Pseudomonas, Rhodococcus, Streptomyces and Variovorax. Approximately, 32% of bacterial isolates, including Arthrobacter, Pseudomonas, Streptomyces, Enterobacter, Nocardia, Acinetobacter and Microbacterium, were able to utilize all five different hydrocarbons compounds. Additionally, 5% of tested isolates belonging to genera Pseudomonas, Acinetobacter, Serratia, Klebsiella, Microbacterium, Bacillus and Stenotrophomonas possessed all five of the tested PGP functional traits. This culture collection of diverse, petroleum-hydrocarbon degrading bacteria, with multiple PGP traits, represents a valuable resource for future use in environmental bio- and phyto-technology applications, including phytoremediation of petroleum hydrocarbons contaminated soils and phytomanagement of anthropized areas.
Subject: Biology, Anatomy & Morphology Keywords: Chlorophyll fluorescence; clary sage; nutrient uptake; oxidative stress; photosynthesis; phytoremediation; phytostabilization; photosynthetic pigments; phenolic content; Zn toxicity
Online: 2 December 2020 (15:36:30 CET)
The responses of the aromatic and medicinal plant Salvia sclarea (clary sage) to 900 µM Zn exposure for 8 days in a hydroponic culture were investigated. The tolerance mechanisms under excess Zn exposure were assessed by changes in nutrient uptake, photosynthetic characteristics and leaf structure. The uptake and the distribution of Zn, as well as some essential nutrient elements such as: Ca, Mg, Fe, Mn and Cu, were examined by inductively coupled plasma mass spectrometry (ICP-MS). The results revealed that Salvia sclarea is a Zn accumulator plant that tolerates significantly high toxic levels of Zn in the leaves by increasing the leaf content of Fe, Ca and Mn ions to protect the photosynthetic function and even stimulate photosystem I (PSI) and photosystem II (PSII) activities. Additionally, the leaf photosynthetic pigments and the total phenolic and anthocyanin content were also studied. Data showed that the exposure to excess Zn significantly increases the synthesis of phenolic compounds in the leaves which plays an important role in the Zn detoxification and protection against oxidative stress. Lipid peroxidation and electrolyte leakage in leaves used as clear indicators for heavy metal damage were slightly increased. All these data highlight that Salvia sclarea is an economically interesting plant for phytoextraction and/or phytostabilization of Zn contaminated soils.