Refinar búsqueda
Resultados 771-780 de 6,558
Microalgae-based bioremediation of water contaminated by pesticides in peri-urban agricultural areas Texto completo
2020
García-Galán, María Jesús | Monllor-Alcaraz, Luis Simón | Postigo, Cristina | Uggetti, Enrica | López de Alda, Miren | Díez-Montero, Rubén | García, Joan
Microalgae-based bioremediation of water contaminated by pesticides in peri-urban agricultural areas Texto completo
2020
García-Galán, María Jesús | Monllor-Alcaraz, Luis Simón | Postigo, Cristina | Uggetti, Enrica | López de Alda, Miren | Díez-Montero, Rubén | García, Joan
The present study evaluated the capacity of a semi-closed, tubular horizontal photobioreactor (PBR) to remove pesticides from agricultural run-off. The study was carried out in summer (July) to study its efficiency under the best conditions (highest solar irradiation). A total of 51 pesticides, including 10 transformation products, were selected and investigated based on their consumption rate and environmental relevance. Sixteen of them were detected in the agricultural run-off, and the estimated removal efficiencies ranged from negative values, obtained for 3 compounds, namely terbutryn, diuron and imidacloprid, to 100%, achieved for 10 compounds. The acidic herbicide MCPA was removed by 88% in average, and the insecticides 2,4-D and diazinon showed variable removals, between 100% and negative values. The environmental risk associated to the compounds still present in the effluent of the PBR was evaluated using hazard quotients (HQs), calculated using the average and highest measured concentrations of the compounds. HQ values > 10 (meaning high risk) were obtained for imidacloprid (21), between 1 and 10 (meaning moderate risk) for 2,4-D (2.8), diazinon (4.6) and terbutryn (1.5), and <1 (meaning low risk) for the remaining compounds diuron, linuron and MCPA. The PBR treatment yielded variable removals depending on the compound, similarly to conventional wastewater treatment plants. This study provides new data on the capacity of microalgae-based treatment systems to eliminate a wide range of priority pesticides under real/environmental conditions.
Mostrar más [+] Menos [-]Microalgae-based bioremediation of water contaminated by pesticides in peri-urban agricultural areas Texto completo
2020
García-Galán, M. Jesús | Monllor-Alcaraz, Luis Simón | Postigo, Cristina | Uggetti, Enrica | López de Alda, Miren | García, Joan | Díez-Montero, Rubén | European Commission | Postigo, Cristina [0000-0002-7344-7044] | López De Alda, Miren [0000-0002-9347-2765]
It is possible to consult this version in open access at the following web address: arXiv:2011.11546 | The present study evaluated the capacity of a semi-closed, tubular horizontal photobioreactor (PBR) to remove pesticides from agricultural run-off. The study was carried out in July to study its efficiency under the best conditions (highest solar irradiation). A total of 51 pesticides, including 10 transformation products, were selected and investigated based on their consumption rate and environmental relevance. Sixteen of them were detected in the agricultural run-off, and the estimated removal efficiencies ranged from negative values, obtained for 3 compounds, namely terbutryn, diuron and imidacloprid, to 100%, achieved for 10 compounds. The acidic herbicide MCPA was removed by 88% in average, and the insecticides 2,4-D and diazinon showed variable removals, between 100% and negative values. The environmental risk associated to the compounds still present in the effluent of the PBR was evaluated using hazard quotients (HQs), calculated using the average and highest measured concentrations of the compounds. HQ values > 10 (meaning high risk) were obtained for imidacloprid (21), between 1 and 10 (meaning moderate risk) for 2,4-D (2.8), diazinon (4.6) and terbutryn (1.5), and <1 (meaning low risk) for the remaining compounds diuron, linuron and MCPA. The PBR treatment yielded variable removals depending on the compound, similarly to conventional wastewater treatment plants. This study provides new data on the capacity of microalgae-based treatment systems to eliminate a wide range of priority pesticides under real/environmental conditions. | This research was funded by European Union's Horizon 2020 research and innovation program within the framework of the INCOVER project (GA 689242) and WATERPROTECT project (727450); by the Spanish Ministry of Science, Innovation and Universities, the Research National Agency (AEI), and the European Regional Development Fund (FEDER) within the project AL4BIO (RTI2018-099495-B-C21), and by the Government of Catalonia (Consolidated Research Group 2017 SGR 01404-Water and Soil Quality Unit). M.J. García-Galán, E. Uggetti and R. Díez-Montero would like to thank the Spanish Ministry of Economy and Competitiveness for their research grants (IJCI-2017-34601, RYC2018-025514-I and FJCI-2016-30997, respectively). | Peer reviewed
Mostrar más [+] Menos [-]Microalgae-based bioremediation of water contaminated by pesticides in peri-urban agricultural areas Texto completo
2020
García Galán, María Jesús | Monllor Alcaraz, Luis Simon | Postigo Rebollo, Cristina | Uggetti, Enrica | López de Alda Villaizan, Miren | García Serrano, Joan | Díez Montero, Rubén | Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental | Universitat Politècnica de Catalunya. GEMMA - Grup d'Enginyeria i Microbiologia del Medi Ambient
The present study evaluated the capacity of a semi-closed, tubular horizontal photobioreactor (PBR) to remove pesticides from agricultural run-off. The study was carried out in summer (July) to study its efficiency under the best conditions (highest solar irradiation). A total of 51 pesticides, including 10 transformation products, were selected and investigated based on their consumption rate and environmental relevance. Sixteen of them were detected in the agricultural run-off, and the estimated removal efficiencies ranged from negative values, obtained for 3 compounds, namely terbutryn, diuron and imidacloprid, to 100%, achieved for 10 compounds. The acidic herbicide MCPA was removed by 88% in average, and the insecticides 2,4-D and diazinon showed variable removals, between 100% and negative values. The environmental risk associated to the compounds still present in the effluent of the PBR was evaluated using hazard quotients (HQs), calculated using the average and highest measured concentrations of the compounds. HQ values > 10 (meaning high risk) were obtained for imidacloprid (21), between 1 and 10 (meaning moderate risk) for 2,4-D (2.8), diazinon (4.6) and terbutryn (1.5), and <1 (meaning low risk) for the remaining compounds diuron, linuron and MCPA. The PBR treatment yielded variable removals depending on the compound, similarly to conventional wastewater treatment plants. This study provides new data on the capacity of microalgae-based treatment systems to eliminate a wide range of priority pesticides under real/environmental conditions. | This research was funded by European Union's Horizon 2020 research and innovation program within the framework of the INCOVER project (GA 689242) and WATERPROTECT project (727450); by the Spanish Ministry of Science, Innovation and Universities, the Research National Agency (AEI), and the European Regional Development Fund (FEDER) within the project AL4BIO (RTI2018-099495-B-C21), and by the Government of Catalonia (Consolidated Research Group 2017 SGR 01404-Water and Soil Quality Unit). M.J. García-Galán, E. Uggetti and R. Díez-Montero would like to thank the Spanish Ministry of Economy and Competitiveness for their research grants (IJCI-2017-34601, RYC2018-025514-I and FJCI-2016-30997, respectively). | Peer Reviewed | Postprint (author's final draft)
Mostrar más [+] Menos [-]Comparison of arsenic fractions and health risks in PM2.5 before and after coal-gas replacement Texto completo
2020
Xie, Jiao-Jiao | Yuan, Chun-Gang | Xie, Jin | Niu, Xiao-Dong | Zhang, Xu-Rui | Zhang, Ke-Gang | Xu, Pei-Yao | Ma, Xiao-Ying | Lv, Xiang-Bing
Coal-Gas replacement project has been implemented to decrease haze pollution in China in recent years. Airborne arsenic (As) mostly originates from coal burning processes. It is noteworthy to compare the distribution of arsenic fraction in PM₂.₅ before and after coal-gas replacement. Eighty PM₂.₅ samples were collected in Baoding in December 2016 (coal dominated year) and December 2017 (gas dominated year) at different functional areas including residential area (RA), industrial area (IA), suburb (SB), roadside (ST) and Botanical Garden Park (BG). The fraction, bioavailability and health risk of As in the PM₂.₅ samples were investigated and compared between these two years. Arsenic was mainly distributed in the non-specifically sorbed fraction (F1) and the residual fraction (F5). However, the proportion of F1 to the total As in 2017 was higher than that in 2016, while the proportion of As in the amorphous and poorly-crystalline hydrous oxides of Fe and Al fraction (F3) in 2017 was lower. The distributions of fraction and bioavailability showed temporal and spatial characteristics. The total concentration and bioavailability of As in SB and IA were significantly higher than those in RA, ST and BG. The BF (Bioavailability Factor) values of As ranged from 0.30 to 0.61. Health risk assessment indicated that the hazard quotient (HQ) and carcinogenic risk (CR) of As in PM₂.₅ significantly decreased after coal-gas replacement.
Mostrar más [+] Menos [-]High-effectively degrade the di-(2-ethylhexyl) phthalate via biochemical system: Resistant bacterial flora and persulfate oxidation activated by BC@Fe3O4 Texto completo
2020
Xie, Yanluo | Liu, Huakang | Li, Hao | Tang, Hao | Peng, He | Xu, Heng
Di-(2-ethylhexyl) phthalate (DEHP) has been classified as a priority pollutant which increased the healthy risk to human and animals dramatically. Hence, a novel biochemical system combined by DEHP-resistant bacterial flora (B) and a green oxidant of persulfate (PS) activated by Nano-Fe₃O₄ was applied to degrade DEHP in contaminated soil. In this study, the resistant bacterial flora was screened from activated sludge and immobilized by sodium alginate (SAB). Nano-Fe₃O₄ was coated on biochar (BC@Fe₃O₄) to prevent agglomerating in soil. X-ray diffraction (XRD) and scanning electron microscope (SEM) were utilized to characterize BC@Fe₃O₄. Results demonstrated that the treatment of biochemical system (SAB + BC@Fe₃O₄ + PS) presented the maximum degradation rate about 92.56% within 24 days of incubation and improved soil microecology. The 16S rDNA sequences analysis of soil microorganisms showed a significantly different abundance and a similar diversity among different treatments. Kyoto Encyclopedia of Genes and Genomes (KEGG) functional genes difference analysis showed that some metabolic pathways, such as metabolism of cofactors and vitamins, energy metabolism, cell growth and death, replication and repair, were associated with the biodegradation of DEHP. Besides, DEHP was converted to MEHP and PA by biodegradation, while DEHP was converted to DBP and PA by persulfate and BC@Fe₃O₄, and then ultimately degraded to CO₂ and H₂O.
Mostrar más [+] Menos [-]Spread of chloramphenicol and tetracycline resistance genes by plasmid mobilization in agricultural soil Texto completo
2020
Lu, Wenwei | Wang, Min | Wu, Jianqiang | Jiang, Qiuyan | Jin, Jieren | Jin, Qing | Yang, Wenwu | Chen, Jun | Wang, Yujing | Xiao, Ming
Spread of antibiotic resistance genes (ARGs) poses a worldwide threat to public health and food safety. However, ARG spread by plasmid mobilization, a broad host range transfer system, in agricultural soil has received little attention. Here, we investigated the spread of chloramphenicol resistance gene (CRG) and tetracycline resistance gene (TRG) in agricultural soil by mobilization of pSUP106 under different conditions, including different concentrations of nutrients, temperatures, soil depths, rhizosphere soils, and soil types. The number of resistant bacteria isolated in non-sterilized soil from the experiments was approximately 10⁴ to 10⁷ per gram of soil, belonging to 5–10 species from four genera, including nonpathogen, opportunistic pathogen, pathogen bacteria, and gram-positive and gram-negative bacteria, depending on the experiment conditions. In sterilized soil, higher levels of nutrients and higher temperatures promoted plasmid mobilization and ARG expression. Topsoil and deep soil might not support the spread of antibiotic resistance, while ARG dissemination by plasmid mobilization was better supported by maize rhizosphere and loam soils. All these factors might change bacterial growth and the activity of bacteria and lead to the above influence. Introduction of only the donor and helper, or the donor alone also resulted in the transfer of ARGs and large numbers of antibiotic resistant bacteria (ARB), indicating that some indigenous bacteria contain the elements necessary for plasmid mobilization. Our results showed that plasmid mobilization facilitated dissemination of ARGs and ARB in soil, which led to the disturbance of indigenous bacterial communities. It is important to clear ARG dissemination routes and inhibit the spread of ARGs.
Mostrar más [+] Menos [-]Analysis of Environmental Impacts on the Characteristics of Gas Released from Biomass Texto completo
2020
Reza Alayi | Ehsan Sobhani | Atabak Najafi
Due to population growth and increased production of municipal solid waste, it is important to utilize this unused energy source, With the right technology, this resource can be used as energy production. Sources of biomass include various natural and derived materials, such as woody and herbaceous species, solid wastes (e.g. from forest thinning and harvesting, timber production and carpentry residues), agricultural and industrial residues, waste paper, municipal solid waste, sawdust, grass, waste from food processing, animal wastes, aquatic plants and industrial and energy crops grown for biomass In this study, in order to produce gas with high calorific value of solid waste in Tehran, a wide variety of compounds, steam and air intake fixed bed reactor has been investigated to identify the best combination. This essay will focus on the production of biogas with high calorific value. In this research, different compositions of air and steam as a reactor input have been examined and fixed base gasifier behavior in different situations have been specified which demonstrate that, best amount of air-steam composition with the most heat valuation is 12.26 (lb/s) for air input and 9.989 (lb/s) for steam input.
Mostrar más [+] Menos [-]Ozone Formation Potential and Toxicity Potential of VOCs emissions from a Nigerian petroleum products depot Texto completo
2020
Ismail Muhibbu-din
Abstract: Emissions of volatile organic compounds (VOCs) are major causes of tropospheric ozone and aerosol pollutions. This research provided information on ozone formation potential (OFP) and toxicity potential (TP) resulting from VOCs emission from a Nigeria petroleum depot. In this work, speciated VOCs were provided on basis of updated emissions within and around the depot. The observed concentration of individual VOCs and maximum incremental reactivity (MIR) coefficient were applied to assess the OFP of individual VOC in the ambient atmosphere. Major aromatic VOCs species were considered at various locations. The total OFP in the atmosphere of the depot is 1522.42 μg O3/m3. Toluene specie was revealed to be major contributor to OFP with 71.47% while others species were in descending order of benzene (9.16%), m-xylene (8.41%), ethyl benzene (3.98%), p-xylene (3.51%) and o-xylene (3.46%). The TP levels of aerosols pollutions were also reported with respect to locations. The Slop tank area had the highest OFP and TP level. An assessment of TP level and OFP suggests that occupants of some location within the depot are exposed to unhealthy air conditions. The study established that OFP and TP have a relationship within the atmosphere of the depot with respect to location. It is recommended that aggressive controlled measures of VOCs sources should be adopted within the petroleum depot as a way of curtailing the impact of tropospheric ozone and aerosol pollutions.
Mostrar más [+] Menos [-]Investigation of Ambient Aromatic Volatile Organic Compounds in Mosimi Petroleum Products Depot, Sagamu, Nigeria Texto completo
2020
Ismail Muhibbu-din
Among chemical industries, petroleum depots have been identified as large emitters of Volatile Organic Compounds (VOCs).They affect air quality and constitute serious health and environmental problems on the ecosystem. Air samples were collected over activated charcoal, using a low volume air sampler. The sampler was placed at a human breathing height of 1.5 m for a sampling period of 8 hours at seven different sampling locations as follows; Workshop area, Slop Tanks area, Gate 1, Tank Farm area, Gate 2, Otiyelu Village and Marketerâs Block. Desorption process was performed on the adsorbed activated charcoal using a solvent extraction method. The extracted solutions were subjected to Flame Ionization Detection analysis in a Gas Chromatograph using a capillary column HP 5MS with length, inner diameter and particle size set at (30 m à 0.25 mm à 0.25 μm). The Gas Chromatograph was powered with ChemStation RevA09.01 software to determine the concentrations of each of the VOCs species present. The sampling collection and quantitative analysis described above is consistent with ANSI/ASTM D-1605-60 procedure. The identified VOCs species emitted were characterized by toluene (52.84%), benzene (37.61%), xylene (5.67%), and ethyl benzene (3.88%). The observed concentrations uncovered the air tolerance limits set by United States Environmental Protection Agency and the Agency for Toxic Substances and Diseases Registry.
Mostrar más [+] Menos [-]Comparison of the application of Heavy metals adsorption methods from aqueous solutions for development of sustainable environment Texto completo
2020
Hamid Gooran Ourimi | Mehdi Nezhadnaderi
Pollution of water by heavy metals is a major problem such as mercury, lead, cadmium, cobalt, etc. The presence of toxic metals in the environment has detrimental effects on human and animal health and disrupts the balance and order of the ecosystem. Therefore, it is necessary to study the ways to eliminate these pollutants. The aim of this study was to compare nickel metal uptake by biological uptake methods with the help of bacterium and brown algae Sargasom, Focus and Grasilaria red algae and nanotechnology method. Based on the previous interpretations, the processes of removal of nickel from industrial wastewater was compared. Research question is that which method is more effective for removal of heavy metals? Results show that biosorption, as an environmentally friendly method, has a brilliant performance and is a low-cost internal method for wastewater treatment. The biological treatment of effluents is carried out by bacteria, some fungi, algae and protozoa to examine the conversion of effluent into a harmless state. Also results show that Iron-based nanostructured particles are capable of decomposing highly stable contaminants such as perchlorate compounds, air nitrate, heavy metals (nickel and mercury) and radioactive materials such as uranium dioxide. Nanostructured particles are used for immediate treatment of sediments, water treatment and liquid waste.
Mostrar más [+] Menos [-]Phytoplankton biomass and composition as useful tools for assessing the impact of early anthropogenic pressure in the Western Mediterranean Texto completo
2020
Goffart, Anne | HCMR, ISPRA, OGS Italy, IFREMER et al (voir https://medregion.eu/about/background/)
In accordance with Article 1 (3) of Directive 2008/56/EC (Marine Strategy Framework Directive, MSFD), the collective pressure of human activities needs to be kept within levels compatible with the achievement of Good Environmental Status (GES), ensuring that the capacity of marine ecosystems to respond to human-induced changes is not compromised. Focusing on long-term time series of environmental and phytoplankton data acquired in Corsican coastal waters, we show how phytoplankton biomass and composition can be used to assess the impact of climate variation and early eutrophication processes. We identify some gaps in information required to implement the MSFD at a regional scale and we propose key directions to overcome them. | MEDREGION
Mostrar más [+] Menos [-]Ingestion of microplastics and occurrence of parasite association in Mediterranean anchovy and sardine Texto completo
2020
Pennino, Maria Grazia | Bachiller, Eneko | Lloret-lloret, Elena | Albo-puigserver, Marta | Esteban, Antonio | Jadaud, Angelique | Bellido, José María | Coll, Marta
We quantified the incidence of microplastics in the gut contents of the European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Northwestern Mediterranean Sea and tested which variables influence this abundance, including the prevalence of parasites (i.e., trematoda larvae and nematodes). We detected a 58% occurrence of microplastics ingestion in sardines and a 60% in anchovies. With respect to sardines, the individuals with lower body conditions were found to have the highest microplastics ingestion probabilities, whereas in anchovies such probabilities were observed in individuals with higher gonadosomatic indices and smaller size. The areas with the highest microplastics ingestion probabilities were the Gulf of Alicante for sardines and the Gulf of Lion - Ebro Delta for anchovies. Both species showed a positive relationship between parasites and microplastics ingestion. These results highlight that both parasitism and ingestion of microplastics are concerns for the health of marine stocks and human consumers.
Mostrar más [+] Menos [-]