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Fate of copper complexes in hydrothermally altered deep-sea sediments from the Central Indian Ocean Basin Полный текст
2014
Chakraborty, Parthasarathi | Sander, Sylvia G. | Jayachandran, Saranya | Nath, B Nagender | Nagaraju, G. | Chennuri, Kartheek | Vudamala, Krushna | Lathika, N. | Mascarenhas-Pereira, Maria Brenda L.
The current study aims to understand the speciation and fate of Cu complexes in hydrothermally altered sediments from the Central Indian Ocean Basin and assess the probable impacts of deep-sea mining on speciation of Cu complexes and assess the Cu flux from this sediment to the water column in this area. This study suggests that most of the Cu was strongly associated with different binding sites in Fe-oxide phases of the hydrothermally altered sediments with stabilities higher than that of Cu-EDTA complexes. The speciation of Cu indicates that hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may not significantly contribute to the global Cu flux. However, increasing lability of Cu-sediment complexes with increasing depth of sediment may increase bioavailability and Cu flux to the global ocean during deep-sea mining.
Показать больше [+] Меньше [-]Soil acidification increases metal extractability and bioavailability in old orchard soils of Northeast Jiaodong Peninsula in China Полный текст
2014
Li, Lianzhen | Wu, Huifeng | van Gestel, Cornelis A.M. | Peijnenburg, Willie J.G.M. | Allen, Herbert E.
The bioavailability of Cu, Zn, Pb and Cd from field-aged orchard soils in a certified fruit plantation area of the Northeast Jiaodong Peninsula in China was assessed using bioassays with earthworms (Eisenia fetida) and chemical assays. Soil acidity increased with increasing fruit cultivation periods with a lowest pH of 4.34. Metals were enriched in topsoils after decades of horticultural cultivation, with highest concentrations of Cu (132 kg−1) and Zn (168 mg kg−1) in old apple orchards and Pb (73 mg kg−1) and Cd (0.57 mg kg−1) in vineyard soil. Earthworm tissue concentrations of Cu and Pb significantly correlated with 0.01 M CaCl2-extractable soil concentrations (R2 = 0.70, p < 0.001 for Cu; R2 = 0.58, p < 0.01 for Pb). Because of the increased bioavailability, regular monitoring of soil conditions in old orchards and vineyards is recommended, and soil metal guidelines need reevaluation to afford appropriate environmental protection under acidifying conditions.
Показать больше [+] Меньше [-]Arsenic speciation in total contents and bioaccessible fractions in atmospheric particles related to human intakes Полный текст
2014
Huang, Minjuan | Chen, Xunwen | Zhao, Yinge | Yu Chan, Chuen | Wang, Wei | Wang, Xuemei | Wong, Ming Hung
Speciation of inorganic trivalent arsenicals (iAsIII), inorganic pentavalent arsenicals (iAsV), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in total arsenic (As) content and its bioaccessible fractions contained in road dust, household air-conditioning (AC) filter dust and PM2.5 was investigated. Inorganic As, especially iAsV, was observed as the dominant species. Physiologically based extraction test (PBET), an in-vitro gastrointestinal method, was used to estimate the oral As bioaccessibility in coarse particles and the species present in the oral bioaccessible fraction. A composite lung simulating serum was used to mimic the pulmonary condition to extract the respiratory bioaccessible As and its species in PM2.5. Reduction of iAsV to iAsIII occurred in both in-vitro gastrointestinal and lung simulating extraction models. The inorganic As species was the exclusive species for absorption through ingestion and inhalation of atmospheric particles, which was an important exposure route to inorganic As, in addition to drinking water and food consumption.
Показать больше [+] Меньше [-]Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments Полный текст
2014
Baena-Nogueras, Rosa María | Rojas-Ojeda, Patricia | Sanz, José Luis | González-Mazo, Eduardo | Lara-Martín, Pablo A.
Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments Полный текст
2014
Baena-Nogueras, Rosa María | Rojas-Ojeda, Patricia | Sanz, José Luis | González-Mazo, Eduardo | Lara-Martín, Pablo A.
This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges. We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains (from up to 141 L kg−1 for C14 to up to 1753 L kg−1 for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive β-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals.
Показать больше [+] Меньше [-]Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments Полный текст
Baena Nogueras, Rosa María | Rojas Ojeda, Patricia | Sanz, José Luis | González Mazo, Eduardo | Lara Martín, Pablo Antonio | Química Física
This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges.We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains(from up to 141 L kg 1 for C14 to up to 1753 L kg 1 for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive b-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals.
Показать больше [+] Меньше [-]Assessing biochar's ability to reduce bioavailability of aminocyclopyrachlor in soils Полный текст
2014
Rittenhouse, Jennifer L. | Rice, Pamela J. | Spokas, Kurt A. | Koskinen, William C.
Aminocyclopyrachlor is a pyrimidine carboxylic acid herbicide used to control broadleaf weeds and brush. Amending soil with activated charcoal is recommended to prevent off-site transport of aminocyclopyrachlor and non-target plant damage. We used the batch-equilibrium method to determine the concentration of aminocyclopyrachlor in a pseudo-steady state with biochar, soil, and biochar-soil systems (<10% biochar by weight). We observed that aminocyclopyrachlor is mobile in soils. Soil incorporation of activated charcoal removed nearly all of the aqueous aminocyclopyrachlor thereby limiting its bioavailability to non-target flora. On the other hand, biochars were less effective than activated charcoal. Biochar produced from olive mill waste feedstock was the most effective biochar that we assessed for reducing the aqueous herbicide concentration. Although these biochars reduced the aminocyclopyrachlor concentration, they would not be practical remediation media due to the extraordinarily high application rates required to reduce the concentration by 50% (2.13 × 105 kg ha−1–7.27 × 105 kg ha−1).
Показать больше [+] Меньше [-]Bacterial metal resistance genes and metal bioavailability in contaminated sediments Полный текст
2014
Roosa, Stéphanie | Wattiez, Ruddy | Prygiel, Emilie | Lesven, Ludovic | Billon, Gabriel | Gillan, David C.
In bacteria a metal may be defined as bioavailable if it crosses the cytoplasmic membrane to reach the cytoplasm. Once inside the cell, specific metal resistance systems may be triggered. In this research, specific metal resistance genes were used to estimate metal bioavailability in sediment microbial communities. Gene levels were measured by quantitative PCR and correlated to metals in sediments using five different protocols to estimate dissolved, particle-adsorbed and occluded metals. The best correlations were obtained with czcA (a Cd/Zn/Co efflux pump) and Cd/Zn adsorbed or occluded in particles. Only adsorbed Co was correlated to czcA levels. We concluded that the measurement of czcA gene levels by quantitative PCR is a promising tool which may complement the classical approaches used to estimate Cd/Zn/Co bioavailability in sediment compartments.
Показать больше [+] Меньше [-]Evaluation of the leucine incorporation technique for detection of pollution-induced community tolerance to copper in a long-term agricultural field trial with urban waste fertilizers Полный текст
2014
Lekfeldt, Jonas Duus Stevens | Magid, Jakob | Holm, Peter E. | Nybroe, Ole | Brandt, Kristian Koefoed
Copper (Cu) is known to accumulate in agricultural soils receiving urban waste products as fertilizers. We here report the use of the leucine incorporation technique to determine pollution-induced community tolerance (Leu-PICT) to Cu in a long-term agricultural field trial. A significantly increased bacterial community tolerance to Cu was observed for soils amended with organic waste fertilizers and was positively correlated with total soil Cu. However, metal speciation and whole-cell bacterial biosensor analysis demonstrated that the observed PICT responses could be explained entirely by Cu speciation and bioavailability artifacts during Leu-PICT detection. Hence, the agricultural application of urban wastes (sewage sludge or composted municipal waste) simulating more than 100 years of use did not result in sufficient accumulation of Cu to select for Cu resistance. Our findings also have implications for previously published PICT field studies and demonstrate that stringent PICT detection criteria are needed for field identification of specific toxicants.
Показать больше [+] Меньше [-]Metal pollution in a contaminated bay: Relationship between metal geochemical fractionation in sediments and accumulation in a polychaete Полный текст
2014
Fan, Wenhong | Xu, Zhizhen | Wang, Wen-Xiong
Jinzhou Bay in Northern China has been seriously contaminated with metals due to the impacts of smelting activities. In this study, we investigated the relationship between metal accumulation in a deposit-feeding polychaete Neanthes japonica and metal concentration and geochemical fractionation (Cd, Cu, Pb, Zn and Ni) in sediments of Jinzhou Bay. Compared with the historical data, metals in the more mobile geochemical fraction (exchangeable and carbonate fractions) were gradually partitioned into the more stable fraction (Fe–Mn oxides) over time. Metal concentration and geochemical fractionation in sediment significantly affected metal bioavailability and accumulation in polychaetes, except for Ni. Metal accumulation in polychaetes was significantly influenced by Fe or Mn content, and to a lesser degree by organic matter. Prediction of metal bioaccumulation in polychaetes was greatly improved by normalizing metal concentrations to Mn content in sediment. The geochemical fractionation of metals in sediments including the exchangeable, organic matter and Fe–Mn oxides were important in controlling the sediment metal bioavailability to polychaetes.
Показать больше [+] Меньше [-]Relating metal bioavailability to risk assessment for aquatic species: Daliao River watershed, China Полный текст
2014
Han, Shuping | Zhang, Ying | Masunaga, Shigeki | Zhou, Siyun | Naito, Wataru
The spatial distribution of metal bioavailability (Ni, Cu, Zn, and Pb) was first evaluated within the waters of Daliao River watershed, using the diffusive gradient in thin films (DGT) and chemical equilibrium models. To assess potential risks associated with metal bioavailability, site-specific 95% protection levels (HC5), risk characterizations ratios (RCR) and ratios of DGT-labile/HC5 were derived, using species sensitivity distribution (SSD). The highest bioavailability values for metals were recorded in the main channel of the Daliao River, followed by the Taizi River. Dynamic concentrations predicted by WHAM 7.0 and NICA-Donnan for Cu and Zn agreed well with DGT results. The estuary of the Daliao River was found to have the highest risks related to Ni, Cu, and Zn. The number of sites at risk increased when considering the total toxicity of Ni, Cu, and Zn.
Показать больше [+] Меньше [-]Mercury exposure in a large subantarctic avian community Полный текст
2014
Carravieri, Alice | Cherel, Yves | Blévin, Pierre | Brault-Favrou, Maud | Chastel, Olivier | Bustamante, Paco
Mercury exposure in a large subantarctic avian community Полный текст
2014
Carravieri, Alice | Cherel, Yves | Blévin, Pierre | Brault-Favrou, Maud | Chastel, Olivier | Bustamante, Paco
Mercury (Hg) contamination poses potential threats to ecosystems worldwide. In order to study Hg bioavailability in the poorly documented southern Indian Ocean, Hg exposure was investigated in the large avian community of Kerguelen Islands. Adults of 27 species (480 individuals) showed a wide range of feather Hg concentrations, from 0.4 ± 0.1 to 16.6 ± 3.8 μg g−1 dry weight in Wilson's storm petrels and wandering albatrosses, respectively. Hg concentrations increased roughly in the order crustacean- < fish- ≤ squid- ≤ carrion-consumers, confirming that diet, rather than taxonomy, is an important driver of avian Hg exposure. Adults presented higher Hg concentrations than chicks, due to a longer duration of exposure, with the only exception being the subantarctic skua, likely because of feeding habits' differences of the two age-classes in this species. High Hg concentrations were reported for three species of the poorly known gadfly petrels, which merit further investigation.
Показать больше [+] Меньше [-]Mercury exposure in a large subantarctic avian community Полный текст
2014
Carravieri, Alice | Cherel, Yves | Blévin, Pierre | Brault-Favrou, Maud | Chastel, Olivier | Bustamante, Paco | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | LIttoral ENvironnement et Sociétés (LIENSs) ; Institut national des sciences de l'Univers (INSU - CNRS)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | ANR-10-CESA-0016,POLARTOP,Contaminants chez les prédateurs supérieurs polaires: niveaux et effets des polluants organiques et métaux lourds sur la physiologie du stress et le devenir des oiseaux marins des Terres Australes Françaises (TAAF)(2010)
International audience | Mercury (Hg) contamination poses potential threats to ecosystems worldwide. In order to study Hg bioavailability in the poorly documented southern Indian Ocean, Hg exposure was investigated in the large avian community of Kerguelen Islands. Adults of 27 species (480 individuals) showed a wide range of feather Hg concentrations, from 0.4 ± 0.1 to 16.6 ± 3.8 µg g-1 dry weight in Wilson's storm petrels and wandering albatrosses, respectively. Hg concentrations increased roughly in the order crustacean- < fish- ≤ squid- ≤ carrion-consumers, confirming that diet, rather than taxonomy, is an important driver of avian Hg exposure. Adults presented higher Hg concentrations than chicks, due to a longer duration of exposure, with the only exception being the subantarctic skua, likely because of feeding habits' differences of the two age-classes in this species. High Hg concentrations were reported for three species of the poorly known gadfly petrels, which merit further investigation.
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