خيارات البحث
النتائج 181 - 190 من 1,966
Chemical stabilization of metals and arsenic in contaminated soils using oxides – A review النص الكامل
2013
Komárek, Michael | Vaněk, Aleš | Ettler, Vojtéch
Oxides and their precursors have been extensively studied, either singly or in combination with other amendments promoting sorption, for in situ stabilization of metals and As in contaminated soils. This remediation option aims at reducing the available fraction of metal(loid)s, notably in the root zone, and thus lowering the risks associated with their leaching, ecotoxicity, plant uptake and human exposure. This review summarizes literature data on mechanisms involved in the immobilization process and presents results from laboratory and field experiments, including the subsequent influence on higher plants and aided phytostabilization. Despite the partial successes in the field, recent knowledge highlights the importance of long-term and large-scale field studies evaluating the stability of the oxide-based amendments in the treated soils and their efficiency in the long-term.
اظهر المزيد [+] اقل [-]Social [and health] relevance of psychotropic substances monitoring in air النص الكامل
2013
Cecinato, Angelo | Balducci, Catia | Mollica, Roberto | Serpelloni, Giovanni
Drug abuse assessment methods based on measuring illicit substances in waste waters are consolidated. The approach of ambient air monitoring looks questionable, nonetheless it can be explored if the variables determining the drug burdens are accounted for, or suitable co-contaminants are adopted to normalize concentrations to environmental and human contours. The general approach linking the airborne drug concentrations to consumption is presented and the case of cocaine is discussed according to measurements conducted in Italy. The cocaine/nicotine concentration ratio, identified as the most suitable tool, fitted well with anti-drug Police operations and people noticed for drug-related crimes, and with the abuse prevalence estimated in the cities investigated. According to that, the conversion factors of drug concentrations into prevalence estimates seem assessable, provided sufficient databases over space and time are collected. Further investigations are necessary to understand if airborne drugs cause adverse sanitary effects.
اظهر المزيد [+] اقل [-]Fungal hyphae stimulate bacterial degradation of 2,6-dichlorobenzamide (BAM) النص الكامل
2013
Knudsen, Berith Elkær | Ellegaard-Jensen, Lea | Albers, Christian Nyrop | Rosendahl, Søren | Aamand, Jens
Introduction of specific degrading microorganisms into polluted soil or aquifers is a promising remediation technology provided that the organisms survive and spread in the environment. We suggest that consortia, rather than single strains, may be better suited to overcome these challenges.Here we introduced a fungal–bacterial consortium consisting of Mortierella sp. LEJ702 and the 2,6-dichlorobenzamide (BAM)-degrading Aminobacter sp. MSH1 into small sand columns. A more rapid mineralisation of BAM was obtained by the consortium compared to MSH1 alone especially at lower moisture contents. Results from quantitative real-time polymerase chain reaction (qPCR) demonstrated better spreading of Aminobacter when Mortierella was present suggesting that fungal hyphae may stimulate bacterial dispersal. Extraction and analysis of BAM indicated that translocation of the compound was also affected by the fungal hyphae in the sand. This suggests that fungal–bacterial consortia are promising for successful bioremediation of pesticide contamination.
اظهر المزيد [+] اقل [-]Historical arsenic contamination of soil due to long-term phosphate fertiliser applications النص الكامل
2013
Hartley, Tom N. | Macdonald, Andy J. | McGrath, Steve P. | Zhao, Fang-Jie
Archived samples from the Park Grass Experiment, established in 1856, were analysed to determine the impacts of long-term phosphate fertiliser applications on arsenic concentrations in soil and herbage. In plots receiving 35 kg P ha−1 annually (+P), topsoil As concentrations almost doubled from an initial value of ∼10 mg kg−1 during 1888–1947 and remained stable thereafter. The phosphate fertilisers used before 1948 contained 401–1575 mg As kg−1, compared to 1.6–20.3 mg As kg−1 in the later samples. Herbage samples from the +P plots collected during 1888–1947 contained significantly more As than those from the −P plots, but later samples did not differ significantly. Mass-balance calculations show that the increase in soil As can be explained by the As input from P fertiliser applications before 1948. The results demonstrate that the P fertilisers used on the Park Grass Experiment before 1948 caused substantial As contamination of the soil.
اظهر المزيد [+] اقل [-]Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems النص الكامل
2013
Seguí, X. | Pujolasus, E. | Betrò, S. | Àgueda, A. | Casal, J. | Ocampo-Duque, W. | Rudolph, I. | Barra, R. | Páez, M. | Barón, E. | Eljarrat, E. | Barceló, D. | Darbra, R.M.
Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems النص الكامل
2013
Seguí, X. | Pujolasus, E. | Betrò, S. | Àgueda, A. | Casal, J. | Ocampo-Duque, W. | Rudolph, I. | Barra, R. | Páez, M. | Barón, E. | Eljarrat, E. | Barceló, D. | Darbra, R.M.
We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers.
اظهر المزيد [+] اقل [-]Fuzzy model for risk assessment of persistent organic pollutants in aquatic ecosystems النص الكامل
2013
Seguí, X. | Pujolasus, E. | Betrò, S. | Àgueda, A. | Casal, J. | Ocampo-Duque, William | Rudolph, Ignacio | Barra, Ricardo | Páez, Martha | Barón, Enrique | Eljarrat, Ethel | Barceló, Damià | Darbra, Rosa María
We developed a model for evaluating the environmental risk of persistent organic pollutants (POPs) to aquatic organisms. The model is based on fuzzy theory and uses information provided by international experts through a questionnaire. It has been tested in two case studies for a particular type of POPs: brominated flame retardants (BFRs). The first case study is related to the EU-funded AQUATERRA project, with sampling campaigns carried out in two Ebro tributaries in Spain (the Cinca and Vero Rivers). The second one, named the BROMACUA project, assessed different aquatic ecosystems in Chile (San Vicente Bay) and Colombia (Santa Marta Marsh). In both projects, the BFRs under study were polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). However, the model can be extrapolated to other POPs and to different aquatic ecosystems to provide useful results for decision-makers. © 2013 Elsevier Ltd. All rights reserved. | The authors are grateful for the participation of the 38 scientists who replied to the questionnaire. In addition, the authors would like to thank the Autonomous Government of Catalonia (project No. 2009SGR1118), the BBVA Foundation through the BROMACUA project (Evaluación del impacto ambiental de los retardantes de llama bromados en ecosistemas acuáticos de América Latina) and the European Union under the Global Change and Ecosystems (FP6) Water Cycle and Soil Related Aspects (AQUATERRA, Project number 505428). | Peer Reviewed
اظهر المزيد [+] اقل [-]Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: Consequences on biodegradation النص الكامل
2013
Cébron, Aurélie | Faure, Pierre | Lorgeoux, Catherine | Ouvrard, Stéphanie | Leyval, Corinne
Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: Consequences on biodegradation النص الكامل
2013
Cébron, Aurélie | Faure, Pierre | Lorgeoux, Catherine | Ouvrard, Stéphanie | Leyval, Corinne
Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAH availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5–6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.
اظهر المزيد [+] اقل [-]Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: Consequences on biodegradation النص الكامل
2013
Cébron, Aurélie | Faure, Pierre | Lorgeoux, Catherine | Ouvrard, Stéphanie | Leyval, Corinne | Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) | Géologie et gestion des ressources minérales et énergétiques (G2R) ; Université Henri Poincaré - Nancy 1 (UHP)-Institut National Polytechnique de Lorraine (INPL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire Sols et Environnement (LSE) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | INSU-EC2CO-MicrobiEn Program
International audience | Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAR availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5-6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.
اظهر المزيد [+] اقل [-]Photobleaching of lignin derived compounds from pulp mill effluents upon irradiation: The key role of receiving waters النص الكامل
2013
Otero, Marta | Guilherme, Isabela | Santos, Eduarda B.H.
Photobleaching of lignin derived compounds from pulp mill effluents upon irradiation: The key role of receiving waters النص الكامل
2013
Otero, Marta | Guilherme, Isabela | Santos, Eduarda B.H.
Lignin derived macromolecular compounds are the main constituents responsible for the hazardous effects of discharged effluents from the pulp and paper industry in receiving waters. It was shown by ultraviolet–visible (UV–vis) and fluorescence spectroscopies that a selective photodegradation of these structures occurred upon irradiation of fulvic acids (FA) from a kraft pulp mill effluent. Though photodegradation was not remarkably affected by the presence of the natural photosensitizer nitrate, it was inhibited under the presence of chloride. These results indicate that the fate of macromolecular organic matter from kraft pulp mill effluents may be different depending on the type of receiving waters, having a higher persistence when effluents are discharged in estuarine or marine waters than when they are discharged in fresh water.
اظهر المزيد [+] اقل [-]Photobleaching of lignin derived compounds from pulp mill effluents upon irradiation: the key role of receiving waters النص الكامل
2013
Otero, Marta | Guilherme, Isabela | Santos, Eduarda B. H.
Lignin derived macromolecular compounds are the main constituents responsible for the hazardous effects of discharged effluents from the pulp and paper industry in receiving waters. It was shown by ultraviolet–visible (UV–vis) and fluorescence spectroscopies that a selective photodegradation of these structures occurred upon irradiation of fulvic acids (FA) from a kraft pulp mill effluent. Though photodegradation was not remarkably affected by the presence of the natural photosensitizer nitrate, it was inhibited under the presence of chloride. These results indicate that the fate of macromolecular organic matter from kraft pulp mill effluents may be different depending on the type of receiving waters, having a higher persistence when effluents are discharged in estuarine or marine waters than when they are discharged in fresh water. | Authors would like to acknowledge funding from FCT (Fundação para a Ciência e a Tecnologia) to CESAM (Centre for Environmental and Marine Studies). Marta Otero acknowledges support from the Spanish Ministry of Science and Innovation (RYC-2010–05634). | published
اظهر المزيد [+] اقل [-]Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents النص الكامل
2013
Chakraborty, Paromita | Zhang, Gan | Eckhardt, Sabine | Li, Jun | Breivik, Knut | Lam, Paul K.S. | Tanabe, Shinsuke | Jones, K. C. (Kevin C.)
Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents النص الكامل
2013
Chakraborty, Paromita | Zhang, Gan | Eckhardt, Sabine | Li, Jun | Breivik, Knut | Lam, Paul K.S. | Tanabe, Shinsuke | Jones, K. C. (Kevin C.)
Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ25PCBs in the Indian atmosphere was 4460 (±2200) pg/m−3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values.
اظهر المزيد [+] اقل [-]Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents النص الكامل
2013
Chakraborty, Paromita | Zhang, Gan | Eckhardt, Sabine | Li, Jun | Breivik, Knut | Lam, Paul KS | Tanabe, Shinsuke | Jones, Kevin C
Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Sum25PCBs in the Indian atmosphere was 4460 (+/-2200) pg m-3 with a dominance of congeners with 4-7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Sum25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. | acceptedVersion
اظهر المزيد [+] اقل [-]Protective role of fine silts for PAH in a former industrial soil النص الكامل
2013
Pernot, Audrey | Ouvrard, Stéphanie | Leglize, Pierre | Faure, Pierre
Protective role of fine silts for PAH in a former industrial soil النص الكامل
2013
Pernot, Audrey | Ouvrard, Stéphanie | Leglize, Pierre | Faure, Pierre
An original combined organic geochemistry and soil science approach was used to elucidate PAH availability controlling factors in a multi-contaminated industrial soil. Water granulodensimetric fractionation was applied to obtain five water-stable material fractions. These were characterized by elemental, molecular and mineral analysis, and microscopic observations. Among the different fractions, fine silts distinguished themselves by higher carbon and nitrogen contents, lower C/N ratio, an enrichment in total PAH and especially high molecular weight compounds, a coal tar signature and the lowest PAH availability. This fine silt fraction seemed to play a protective role for PAH that might be explained by its size and/or its specific reactivity. The mineral phases present in this fraction were proposed to explain the protection of organic matter. This led to a specific molecular signature of OM, having higher sorption properties both processes (sorption and mineral-bound protection) resulting in a lower PAH availability.
اظهر المزيد [+] اقل [-]Protective role of fine silts for PAH in a former industrial soil النص الكامل
2013
Pernot, Audrey | Ouvrard, Stéphanie | Leglize, Pierre | Faure, Pierre | Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire Sols et Environnement (LSE) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)
International audience | An original combined organic geochemistry and soil science approach was used to elucidate PAH availability controlling factors in a multi-contaminated industrial soil. Water granulodensimetric fractionation was applied to obtain five water-stable material fractions. These were characterized by elemental, molecular and mineral analysis, and microscopic observations. Among the different fractions, fine silts distinguished themselves by higher carbon and nitrogen contents, lower C/N ratio, an enrichment in total PAH and especially high molecular weight compounds, a coal tar signature and the lowest PAH availability. This fine silt fraction seemed to play a protective role for PAH that might be explained by its size and/or its specific reactivity. The mineral phases present in this fraction were proposed to explain the protection of organic matter. This led to a specific molecular signature of OM, having higher sorption properties both processes (sorption and mineral-bound protection) resulting in a lower PAH availability. (C) 2013 Elsevier Ltd. All rights reserved.
اظهر المزيد [+] اقل [-]Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina النص الكامل
2013
Carreras, Hebe A. | Calderón-Segura, Marıa Elena | Gómez-Arroyo, Sandra | Murillo-Tovar, Mario A. | Amador-Muñoz, Omar
Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina النص الكامل
2013
Carreras, Hebe A. | Calderón-Segura, Marıa Elena | Gómez-Arroyo, Sandra | Murillo-Tovar, Mario A. | Amador-Muñoz, Omar
The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency.
اظهر المزيد [+] اقل [-]Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina النص الكامل
2013
Carreras, Hebe Alejandra | Calderon Segura, María Elena | Gomez Arroyo, Sandra | Murillo Tovar, Mario A. | Amador Munoz, Omar
The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency. | Fil: Carreras, Hebe Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina | Fil: Calderon Segura, María Elena. Universidad Nacional Autónoma de México; México | Fil: Gomez Arroyo, Sandra. Universidad Nacional Autónoma de México; México | Fil: Murillo Tovar, Mario A.. Universidad Nacional Autónoma de México; México | Fil: Amador Munoz, Omar. Universidad Nacional Autónoma de México; México
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