خيارات البحث
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Standardized emissions inventory methodology for open-pit mining areas النص الكامل
2012
Huertas, Jose I. | Camacho, Dumar A. | Huertas, Maria E.
INTRODUCTION: There is still interest in a unified methodology to quantify the mass of particulate material emitted into the atmosphere by activities inherent to open-pit mining. For the case of total suspended particles (TSP), the current practice is to estimate such emissions by developing inventories based on the emission factors recommended by the USEPA for this purpose. However, there are disputes over the specific emission factors that must be used for each activity and the applicability of such factors to cases quite different to the ones under which they were obtained. There is also a need for particulate matter with an aerodynamic diameter less than 10 μm (PM₁₀) emission inventories and for metrics to evaluate the emission control programs implemented by open-pit mines. STANDARDIZED EMISSION INVENTORY METHODOLOGY: To address these needs, work was carried out to establish a standardized TSP and PM₁₀ emission inventory methodology for open-pit mining areas. The proposed methodology was applied to seven of the eight mining companies operating in the northern part of Colombia, home to the one of the world’s largest open-pit coal mining operations (∼70 Mt/year). RESULTS: The results obtained show that transport on unpaved roads is the mining activity that generates most of the emissions and that the total emissions may be reduced up to 72% by spraying water on the unpaved roads. Performance metrics were defined for the emission control programs implemented by mining companies. It was found that coal open-pit mines are emitting 0.726 and 0.180 kg of TSP and PM₁₀, respectively, per ton of coal produced. It was also found that these mines are using on average 1.148 m² of land per ton of coal produced per year.
اظهر المزيد [+] اقل [-]Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile النص الكامل
2012
Cárcamo, Valeska | Bustamante, Elena | Trangolao, Elizabeth | de la Fuente, Luz María | Mench, Michel | Neaman, Alexander | Ginocchio, Rosanna
Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile النص الكامل
2012
Cárcamo, Valeska | Bustamante, Elena | Trangolao, Elizabeth | de la Fuente, Luz María | Mench, Michel | Neaman, Alexander | Ginocchio, Rosanna
INTRODUCTION: Acidic and metal(oid)-rich topsoils resulted after 34 years of continuous operations of a copper smelter in the Puchuncaví valley, central Chile. Currently, large-scale remediation actions for simultaneous in situ immobilization of metals and As are needed to reduce environmental risks of polluted soils. Aided phytostabilization is a cost-effective alternative, but adequate local available soil amendments have to be identified and management options have to be defined. MATERIALS AND METHODS: Efficacy of seashell grit (SG), biosolids (B), natural zeolite (Z), and iron-activated zeolite (AZ), either alone or in mixtures, was evaluated for reducing metal (Cu and Zn) and As solubilization in polluted soils under laboratory conditions. Perennial ryegrass was used to test phytotoxicity of experimental substrates. RESULTS: Soil neutralization to a pH of 6.5 with SG, with or without incorporation of AZ, significantly reduces metal (Cu and Zn) solubilization without affecting As solubilization in soil pore water; furthermore, it eliminates phytotoxicity and excessive metal(oid) accumulation in aerial plant tissues. Addition of B or Z to SG-amended soil does not further reduce metal solubilization into soil pore water, but increase As solubilization due to excessive soil neutralization (pH > 6.5); however, no significant As increase occurs in aerial plant tissues. CONCLUSION: Simultaneous in situ immobilization of metal(oid) in acidic topsoils is possible through aided phytostabilization.
اظهر المزيد [+] اقل [-]Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile النص الكامل
2012
Cárcamo, Valeska | Bustamante, Elena | Trangolao, Elizabeth | de La Fuente, Luz María | Mench, Michel | Neaman, Alexander | Ginocchio, Rosanna | Universidad de Chile = University of Chile [Santiago] (UCHILE) | Centro de Investigación Minera y Metalúrgica ; Partenaires INRAE | Biodiversité, Gènes & Communautés (BioGeCo) ; Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB) | Centro Regional de Estudios en Alimentos Saludables (CREAS)
International audience | * Introduction : Acidic and metal(oid)-rich topsoils resulted after 34 years of continuous operations of a copper smelter in the Puchuncaví valley, central Chile. Currently, large-scale remediation actions for simultaneous in situ immobilization of metals and As are needed to reduce environmental risks of polluted soils. Aided phytostabilization is a cost-effective alternative, but adequate local available soil amendments have to be identified and management options have to be defined. * Materials and methods : Efficacy of seashell grit (SG), biosolids (B), natural zeolite (Z), and iron-activated zeolite (AZ), either alone or in mixtures, was evaluated for reducing metal (Cu and Zn) and As solubilization in polluted soils under laboratory conditions. Perennial ryegrass was used to test phytotoxicity of experimental substrates. * Results : Soil neutralization to a pH of 6.5 with SG, with or without incorporation of AZ, significantly reduces metal (Cu and Zn) solubilization without affecting As solubilization in soil pore water; furthermore, it eliminates phytotoxicity and excessive metal(oid) accumulation in aerial plant tissues. Addition of B or Z to SG-amended soil does not further reduce metal solubilization into soil pore water, but increase As solubilization due to excessive soil neutralization (pH > 6.5); however, no significant As increase occurs in aerial plant tissues. * Conclusion : Simultaneous in situ immobilization of metal(oid) in acidic topsoils is possible through aided phytostabilization.
اظهر المزيد [+] اقل [-]An integrated approach to identify the origin of PM10 exceedances النص الكامل
2012
Amodio, M. | Andriani, E. | de Gennaro, G. | Demarinis Loiotile, A. | Di Gilio, A. | Placentino, M. C.
PURPOSE: This study was aimed to the development of an integrated approach for the characterization of particulate matter (PM) pollution events in the South of Italy. METHODS: PM10 and PM2.5 daily samples were collected from June to November 2008 at an urban background site located in Bari (Puglia Region, South of Italy). Meteorological data, particle size distributions and atmospheric dispersion conditions were also monitored in order to provide information concerning the different features of PM sources. RESULTS: The collected data allowed suggesting four indicators to characterize different PM10 exceedances. PM2.5/PM10 ratio, natural radioactivity, aerosol maps and back-trajectory analysis and particle distributions were considered in order to evaluate the contribution of local anthropogenic sources and to determine the different origins of intrusive air mass coming from long-range transport, such as African dust outbreaks and aerosol particles from Central and Eastern Europe. The obtained results were confirmed by applying principal component analysis to the number particle concentration dataset and by the chemical characterization of the samples (PM10 and PM2.5). CONCLUSIONS: The integrated approach for PM study suggested in this paper can be useful to support the air quality managers for the development of cost-effective control strategies and the application of more suitable risk management approaches.
اظهر المزيد [+] اقل [-]Degradation and mineralization of sulcotrione and mesotrione in aqueous medium by the electro-Fenton process: a kinetic study النص الكامل
2012
Murati, Minir | Oturan, Nihal | Aaron, Jean-Jacques | Dirany, Ahmad | Tassin, Bruno | Zdravkovski, Z. | Oturan, Mehmet A.
Degradation and mineralization of sulcotrione and mesotrione in aqueous medium by the electro-Fenton process: a kinetic study النص الكامل
2012
Murati, Minir | Oturan, Nihal | Aaron, Jean-Jacques | Dirany, Ahmad | Tassin, Bruno | Zdravkovski, Z. | Oturan, Mehmet A.
INTRODUCTION: The degradation and mineralization of two triketone (TRK) herbicides, including sulcotrione and mesotrione, by the electro-Fenton process (electro-Fenton using Pt anode (EF-Pt), electro-Fenton with BDD anode (EF-BDD) and anodic oxidation with BDD anode) were investigated in acidic aqueous medium. METHODS: The reactivity of both herbicides toward hydroxyl radicals was found to depend on the electron-withdrawing effect of the aromatic chlorine or nitro substituents. The degradation of sulcotrione and mesotrione obeyed apparent first-order reaction kinetics, and their absolute rate constants with hydroxyl radicals at pH 3.0 were determined by the competitive kinetics method. RESULTS AND DISCUSSION: The hydroxylation absolute rate constant (k abs) values of both TRK herbicides ranged from 8.20 × 108 (sulcotrione) to 1.01 × 109 (mesotrione) L mol−1 s−1, whereas those of the TRK main cyclic or aromatic by-products, namely cyclohexane 1,3-dione , (2-chloro-4-methylsulphonyl) benzoic acid and 4-(methylsulphonyl)-2-nitrobenzoic acid, comprised between 5.90 × 108 and 3.29 × 109 L mol−1 s−1. The efficiency of mineralization of aqueous solutions of both TRK herbicides was evaluated in terms of total organic carbon removal. Mineralization yields of about 97–98% were reached in optimal conditions for a 6-h electro-Fenton treatment time. CONCLUSIONS: The mineralization process steps involved the oxidative opening of the aromatic or cyclic TRK by-products, leading to the formation of short-chain carboxylic acids, and, then, of carbon dioxide and inorganic ions.
اظهر المزيد [+] اقل [-]Degradation and mineralization of sulcotrione and mesotrione in aqueous medium by the electro-Fenton process: a kinetic study النص الكامل
2012
Murati, M. | Oturan, Nihal | Aaron, J. J. | Dirany, A. | Tassin, Bruno | Zdravkovski, Z. | Oturan, Mehmet A. | Laboratoire Géomatériaux et Environnement (LGE) ; Université Paris-Est Marne-la-Vallée (UPEM) | Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)) ; Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire Eau, Environnement et Systèmes Urbains (LEESU) ; AgroParisTech-Université Paris-Est Marne-la-Vallée (UPEM)-École nationale des ponts et chaussées (ENPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)
International audience | Introduction: The degradation and mineralization of two triketone (TRK) herbicides, including sulcotrione and mesotrione, by the electro-Fenton process (electro-Fenton using Pt anode (EF-Pt), electro-Fenton with BDD anode (EF-BDD) and anodic oxidation with BDD anode) were investigated in acidic aqueous medium. Methods: The reactivity of both herbicides toward hydroxyl radicals was found to depend on the electron-withdrawing effect of the aromatic chlorine or nitro substituents. The degradation of sulcotrione and mesotrione obeyed apparent first-order reaction kinetics, and their absolute rate constants with hydroxyl radicals at pH 3. 0 were determined by the competitive kinetics method. Results and discussion: The hydroxylation absolute rate constant (kabs) values of both TRK herbicides ranged from 8. 20 × 108 (sulcotrione) to 1. 01 × 109 (mesotrione) L mol-1 s-1, whereas those of the TRK main cyclic or aromatic by-products, namely cyclohexane 1,3-dione, (2-chloro-4-methylsulphonyl) benzoic acid and 4-(methylsulphonyl)-2-nitrobenzoic acid, comprised between 5. 90 × 108 and 3. 29 × 109 L mol-1 s-1. The efficiency of mineralization of aqueous solutions of both TRK herbicides was evaluated in terms of total organic carbon removal. Mineralization yields of about 97-98% were reached in optimal conditions for a 6-h electro-Fenton treatment time. Conclusions: The mineralization process steps involved the oxidative opening of the aromatic or cyclic TRK by-products, leading to the formation of short-chain carboxylic acids, and, then, of carbon dioxide and inorganic ions.
اظهر المزيد [+] اقل [-]Identification of substances with potential for long-range transport as possible substances of very high concern النص الكامل
2012
Zarfl, Christiane | Hotopp, Ines | Kehrein, Nils | Matthies, Michael
According to the European legislation, REACH, organic compounds are considered as substances of very high concern (SVHC) if they are persistent, bioaccumulative and toxic (PBT). A substance’s long-range transport potential (LRTP) may also pose a risk to remote regions. This is, however, not yet explicitly included. For identification of compounds, which are not PBT according to REACH criteria, but show LRTP, we investigated 22,438 compounds from the Canadian Domestic Substance List (CDSL). The CDSL was searched for organic, neutral compounds. Substance properties were estimated with EPI Suite v4.00. Next, the substance list was edited in two ways: (1) The half-life criterion in air for LRTP as defined in the Stockholm Convention was applied. (2) For all compounds, indicators for persistence and LRTP were calculated with the multimedia model ELPOS v2.2. Applying the half-life criterion, we identified 594 substances, which are prone to LRT but are not PBT (non-PBT-L substances). In contrast, investigations with ELPOS lead to a shorter list of 188 substances, which are non-PBT-L substances. Finally, the list was compared with potential Arctic contaminants identified in previous literature. Our results show that there is a large number of organic chemicals which would not be considered as SVHC since they are not, at the same time, persistent, bioaccumulative and toxic according to REACH criteria. Nevertheless, they show LRTP according to different screening approaches and thus a potential hazard to remote regions.
اظهر المزيد [+] اقل [-]Spatial distribution and speciation of mercury and methyl mercury in the surface water of East River (Dongjiang) tributary of Pearl River Delta, South China النص الكامل
2012
Liu, Jinling | Feng, Xinbin | Zhu, Wei | Zhang, Xian | Yin, Runsheng
PURPOSE: The distribution and speciation of mercury in surface water of East River, Guangdong province, China were investigated. METHODS: All told 63 water samples were collected during a bi-weekly sampling campaign from July 15th to 26th, 2009. RESULTS: Total mercury (THg) concentrations in water samples ranged from 11 to 49 ng/L. Maximum levels of THg were measured in the lower reaches of East River, where it passes through a major industrial area adjacent to Dongguang city. Higher ratios of dissolved mercury (THg (aq)) in proportion to THg were restricted to the downstream section of East River. Concentrations of the minor constituent methyl mercury varied in the range from 0.08 to 0.21 ng/L. On average, methyl mercury made up 0.8% and 0.56% of THg (aq) and THg, respectively. Dissolved species dominated the speciation of methyl mercury in proportions up to 81%, which may imply that methyl mercury is largely produced in situ within the river water. Environmental factors (such as water temperature, dissolved oxygen, etc.) are regarded to play an important role in Hg methylation processes were monitored and assessed. CONCLUSIONS: In an international perspective, East River must be classified as a polluted river with considerably sources within its industrial areas. The THg (aq) and particle mercury fluxes to the Pearl River Estuary by East River run-off were estimated to be 0.31 ± 0.11 and 0.17 ± 0.13 t/year, respectively. Hence, in total nearly 0.5 t Hg is annually released to the sea from the East River tributary.
اظهر المزيد [+] اقل [-]Alteration of in vitro and acute in vivo toxicity of textile dyeing wastewater after chemical and biological remediation النص الكامل
2012
Ben Mansour, Hedi | Houas, Ikram | Montassar, Fadoua | Ghedira, Kamel | Barillier, Daniel | Mosrati, Ridha | Chekir-Ghedira, Leila
INTRODUCTION: Textile industry is one of the most common and essential sectors in Tunisia. However, the treatment of textile effluents becomes a university because of their toxic impacts on waters, soils, flora, and fauna. MATERIALS AND METHODS: The aim of this work was to evaluate the ability of Pseudomonas putida mt-2 to decolorize a textile wastewater and to compare the biologic decolorization process to the chemical one currently used by the textile industry. RESULTS: P. putida exhibited a high decolorizing capacity of the studied effluent, compared to the coagulation–flocculation method with decolorization percentage of 86% and 34.5%, respectively. Genotoxicity of the studied effluent, before and after decolorization by P. putida mt-2, was evaluated in vitro, using the SOS chromotest, and in vivo, in mouse bone marrow, by assessing the percentage of cells bearing different chromosome aberrations compared to not treated mice. In addition, textile effluent statistically significant influenced acetylcholinesterase and butyrylcholinesterase activities and lipid peroxidation (p < 0.01) when compared to not-treated mice. Coagulation–flocculation treatment process used by industry was revealed to be ineffective. Indeed toxicities persisted after treatment and the effluent did not show any statistically significant decrease in toxicities compared to non-treated effluent. Our results indicate that P. putida is a promising and improved alternative to treating industrial scale effluent compared to current chemical decolorization procedures used by the Tunisian textile industry.
اظهر المزيد [+] اقل [-]Quantification of bisphenol A, 353-nonylphenol and their chlorinated derivatives in drinking water treatment plants النص الكامل
2012
Dupuis, Antoine | Migeot, Virginie | Cariot, Axelle | Albouy-Llaty, Marion | Legube, Bernard | Rabouan, Sylvie
Bisphenol A (BPA) and nonylphenols (NP) are of major concern to public health due to their high potential for human exposure and to their demonstrated toxicity (endocrine disruptor effect). A limited number of studies have shown that BPA and NP are present in drinking water. The chlorinated derivatives that may be formed during the chlorination step in drinking water treatment plants (DWTP) exhibit a higher level of estrogenic activity than their parent compounds. The aim of this study was to investigate BPA, 353NP, and their chlorinated derivative concentrations using an accurate and reproducible method of quantification. This method was applied to both surface and treated water samples from eight French DWTPs producing from surface water. Solid-phase extraction followed by liquid chromatography–tandem mass spectrometry was developed in order to quantify target compounds from water samples. The limits of detection ranged from 0.3 to 2.3 ng/L for BPA and chlorinated BPA and from 1.4 to 63.0 ng/L for 353NP and chlorinated 353NP. BPA and 353NP were found in most analyzed water samples, at a level ranging from 2.0 to 29.7 ng/L and from 0 to 124.9 ng/L, respectively. In most of DWTPs a decrease of BPA and 353NP was observed between surface water and treated water (36.6 to 78.9 % and 2.2 to 100.0 % for BPA and 353NP, respectively). Neither chlorinated BPA nor chlorinated 353NP was detected. Even though BPA and 353NP have been largely removed in the DWTPs studied, they have not been completely eliminated, and drinking water may consequently remain a source of human exposure.
اظهر المزيد [+] اقل [-]Estrogenic effects of dissolved organic matter and its impact on the activity of 17β-estradiol النص الكامل
2012
Chen, Lei | Shen, Chaofeng | Tang, Xianjin | Chen, Chen | Chen, Yingxu
BACKGROUND AND PURPOSE: The ubiquitous dissolved organic matter (DOM) is actually not inert as we always think, and the hormone-like effects of DOM have been reported. The objective of this study was to investigate the estrogenic effects of DOM and its impact on the activity of the natural estrogen 17β-estradiol (E2). MATERIALS AND METHODS: DOM of three different sources, HA sodium salt, Suwannee River natural organic matter (NOM), and Nordic Reservoir NOM, were used. The estrogenic activity was detected by using the yeast estrogen screen (YES) assay. Estrogenic effects of DOM without and after solar irradiation were tested. Influences on the action of E2 by DOM were also investigated. RESULTS: No direct estrogenic effects of the DOM used were observed in the YES assay. However, the estrogenic activities after 24 h of irradiation increased to 0.0288, 0.0178, and 0.0195 μM of E2 equivalents for HA sodium salt, Suwannee River NOM, and Nordic Reservoir NOM, respectively. After incubation of DOM, the estrogenic activity of E2 was increased by low concentrations (8.33 and 83.3 μM) of DOM while decreased by higher concentrations (8.33 × 102 and 8.33 × 103 μM) of DOM. CONCLUSIONS: Though direct estrogenic effects of DOM were not observed, increase in the estrogenic activity of DOM after irradiation was significant. DOM shows amphoteric influence on the natural estrogen E2, which depends on the concentration of DOM used. Because of its ubiquity, DOM may be of great ecological significance, playing an important role in regulating the reproduction of aquatic organisms.
اظهر المزيد [+] اقل [-]Glutathione, glutathione S-transferase, and glutathione conjugates, complementary markers of oxidative stress in aquatic biota النص الكامل
2012
Hellou, Jocelyne | Ross, Neil W. | Moon, T. W. (Thomas W.)
Contaminants are ubiquitous in the environment and their impacts are of increasing concern due to human population expansion and the generation of deleterious effects in aquatic species. Oxidative stress can result from the presence of persistent organic pollutants, metals, pesticides, toxins, pharmaceuticals, and nanomaterials, as well as changes in temperature or oxygen in water, the examined species, with differences in age, sex, or reproductive cycle of an individual. The antioxidant role of glutathione (GSH), accompanied by the formation of its disulfide dimer, GSSG, and metabolites in response to chemical stress, are highlighted in this review along with, to some extent, that of glutathione S-transferase (GST). The available literature concerning the use and analysis of these markers will be discussed, focusing on studies of aquatic organisms. The inclusion of GST within the suite of biomarkers used to assess the effects of xenobiotics is recommended to complement that of lipid peroxidation and mixed function oxygenation. Combining the analysis of GSH, GSSG, and conjugates would be beneficial in pinpointing the role of contaminants within the plethora of causes that could lead to the toxic effects of reactive oxygen species.
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