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For sulfonamides, the formation of non-extractable residues has been identified by laboratory testing as the most relevant concentration determining process in manured soil. Therefore, the present study has been focused on the chemical and biological characterization of non-extractable residues of 14C-labeled sulfadiazine or sulfamethoxazole. In laboratory batch experiments, the test substances were spiked via standard solution or test slurry to microbially active soil samples. After incubation periods of up to 102 d, a sequential extraction technique was applied. Despite the exhaustive extraction procedure, sulfadiazine residues mainly remained non-extractable, indicating the high affinity to the soil matrix. The remobilization of non-extractable 14C-sulfadiazine residues was monitored in the activated sludge test and the Brassica rapa test. Only small amounts (<3%) were transferred into the extractable fractions and 0.1% was taken up by the plants. In the Lumbricus terrestris test A, the release of non-extractable 14C-sulfamethoxazole residues by the burrowing activity of the earthworms was investigated. The residues mainly remained non-extractable (96%). The L. terrestris test B was designed to study the immobilization of 14C-sulfamethoxazole in soil directly after the test slurry application. The mean uptake by earthworms was 1%. Extractable and non-extractable residues amounted to 5% and 93%, respectively. Consequently, the results of all tests confirmed the high affinity of the non-extractable sulfonamide residues to the soil matrix. 相似文献
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Henner Hollert Susanne Heise Steffen Keiter Peter Heininger Ulrich F?rstner 《Umweltwissenschaften und Schadstoff-Forschung》2006,18(2):148
Tagungsankündigungen
Sedimenttoxizit?t — ein inhaltlicher Schwerpunkt beim SETAC Europe 16th Annual Meeting World Forum Convention Center in Den Haag, Niederlangden, 7–11 Mai 2006 相似文献6.
Risk assessment of contaminated sediments in river basins--theoretical considerations and pragmatic approach 总被引:1,自引:0,他引:1
In order to ensure chemical quality of river basins, measures as required in the Water Framework Directive will also have to address contaminated sediments with subsequent monitoring of their successful application. Financial resources need to be allocated as part of a river basin plan to those contaminated sites that pose the biggest risk to the river basin. In order to differentiate between areas with elevated contaminant levels ("areas of concern") and those sites from which contaminated sediments can become resuspended and transported with the river, affecting the water phase and downstream sites in the catchment ("areas of risk"), the dynamics of sediment and suspended matter need to come into focus. Hydrological data have to be combined with concentration of suspended matter and its contaminant concentration to allow assessment of particle bound contaminant load. Each of these kinds of data, however, are subject to uncertainties--e.g. due to natural variability, heterogeneity of the matrix, challenges during sampling and chemical analyses of the suspended matter. Considering these uncertainties throughout the traceability chains of data collection, use of different lines of evidence and tools like fuzzy logic will increase the confidence of potentially costly management decisions. 相似文献
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Humic colloid-borne migration of uranium in sand columns 总被引:3,自引:0,他引:3
Artinger R Rabung T Kim JI Sachs S Schmeide K Heise KH Bernhard G Nitsche H 《Journal of contaminant hydrology》2002,58(1-2):1-12
Column experiments were carried out to investigate the influence of humic colloids on subsurface uranium migration. The columns were packed with well-characterized aeolian quartz sand and equilibrated with groundwater rich in humic colloids (dissolved organic carbon (DOC): 30 mg dm(-3)). U migration was studied under an Ar/1% CO2 gas atmosphere as a function of the migration time, which was controlled by the flow velocity or the column length. In addition, the contact time of U with groundwater prior to introduction into a column was varied. U(VI) was found to be the dominant oxidation state in the spiked groundwater. The breakthrough curves indicate that U was transported as a humic colloid-borne species with a velocity up to 5% faster than the mean groundwater flow. The fraction of humic colloid-borne species increases with increasing prior contact time and also with decreasing migration time. The migration behavior was attributed to a kinetically controlled association/dissociation of U onto and from humic colloids and also a subsequent sorption of U onto the sediment surface. The column experiments provide an insight into humic colloid-mediated U migration in subsurface aquifers. 相似文献
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Contaminated sediment in the river basin has become a source of pollution with increasing importance to the aquatic ecosystem downstream. To monitor the temporal changes of the sediment bound contaminants in the River Elbe and the River Dommel monthly toxicity tests were applied to layered sediment and river water samples over the course of 10 months. There is an indication that contaminated sediments upstream adversely affected sediments downstream, but this process did not cause a continuous increase of sediment toxicity. A clear decrease of toxic effects in water and upper layer sediment was observed at the River Elbe station in spring related to high water discharge and algal blooms. The less obvious variation of sediment toxicity in the River Dommel could be explained by stable hydrological conditions. Future monitoring programmes should promote a more frequent and intensive sampling regime during these particular events for ecotoxicological evaluation. 相似文献
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OLFA TEBOURBI MOHAMMED RIDHA DRISS MOHSEN SAKLY KHÉMAIS BEN RHOUMA 《Journal of environmental science and health. Part. B》2013,48(2):167-176
The bioconcentration and distribution pattern of p,p′-DDT 1,1,1-1trichloro-2,2-bis(2-chlorophenyl-4-chlorophenyl)-ethane] and its main metabolites (p,p′-DDD [1,1-dichloro-2,2-bis (4-chlorophenyl) ethane] and p,p′-DDE [1,1-dichloro-2,2-bis (4-chlorophenyl) in adipose tissue, liver, brain, kidney, thymus, and testis were examined in young rats after 10 days of intraperitoneal injection of 50 and 100 mg of p,p′-DDT/kg of body weight. Analyses were performed by high-resolution gas chromatography. p,p′-DDT was found to be accumulated in a dose-dependent manner with the highest concentration in adipose tissue. However, in brain, the accumulation of pesticide was low and remained unchanged at the higher dose. This difference may relate to the protective role of the blood-brain barrier, which limits the access of the xenobiotic in the cerebral compartment, and to the differential tissue lipid composition. Although tissues concentration of p,p′-DDE and p,p′-DDD correlated positively to total p,p′-DDT levels, the active role in detoxification of pollutants may explain why p,p′-DDD is more abundant in liver than in the rest of organs. On the contrary, in brain, the concentration of p,p′-DDE is higher than that of p,p′-DDD, suggesting that the metabolism of the parent insecticide proceeds via more than one pathway. 相似文献
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Henner Hollert Susanne Heise Steffen Keiter Peter Heininger Ulrich Förstner 《Environmental Sciences Europe》2007,19(1):58-70