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881.
A. Zierhut K. Leopold L. Harwardt M. Schuster 《Umweltwissenschaften und Schadstoff-Forschung》2010,22(1):72-77
Routinef?hige, kostengünstige analytische Messverfahren sind die Grundlage für ein fl?chendeckendes Umweltmonitoring von Schadstoffen
und somit für die Sicherung unserer Gesundheit und natürlichen Lebensgrundlagen. Hierbei kann die Analytik zur nachhaltigen
Nutzung und zur Schonung unserer Umweltressourcen beitragen, indem auf den Einsatz umweltgef?hrdender Reagenzien verzichtet
wird. 相似文献
882.
Kelly K. Moran Julie D. Jastrow 《Environmental pollution (Barking, Essex : 1987)》2010,158(4):1088-1094
The potential for storing additional C in U.S. Corn Belt soils - to offset rising atmospheric [CO2] - is large. Long-term cultivation has depleted substantial soil organic matter (SOM) stocks that once existed in the region's native ecosystems. In central Illinois, free-air CO2 enrichment technology was used to investigate the effects of elevated [CO2] on SOM pools in a conservation tilled corn-soybean rotation. After 5 and 6 y of CO2 enrichment, we investigated the distribution of C and N among soil fractions with varying ability to protect SOM from rapid decomposition. None of the isolated C or N pools, or bulk-soil C or N, was affected by CO2 treatment. However, the site has lost soil C and N, largely from unprotected pools, regardless of CO2 treatment since the experiment began. These findings suggest management practices have affected soil C and N stocks and dynamics more than the increased inputs from CO2-stimulated photosynthesis. 相似文献
883.
Frederik De Laender K. Soetaert 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1775-1782
The majority of ecotoxicological enclosure experiments monitor species abundances at different chemical concentrations. Here, we present a new modelling approach that estimates changes in food web flows from such data and show that population- and food web level effects are revealed that are not apparent from abundance data alone. For the case of cypermethrin in freshwater enclosures, photosynthesis and excretion (d−1) of phytoplankton at 3.643 μg L−1 cypermethrin were 30% lower and 100% higher than in the control, respectively. The ingestion rate of mesozooplankton (d−1) was 6 times higher in the treated enclosures than in the control as food concentration increased with insecticide exposure. With increasing cypermethrin concentrations, nanoflagellates progressively relied on phytoplankton as their main food source, which rendered the food web less stable. We conclude that this tool has excellent potential to analyse the wealth of enclosure data as it only needs species abundance and general constraints. 相似文献
884.
Ben K. Greenfield Andrew Jahn 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2716-2724
In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 μg g−1 (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. 相似文献
885.
Cornelia Meinert Emma Schymanski Eberhard Küster Ralph Kühne Gerrit Schüürmann Werner Brack 《Environmental science and pollution research international》2010,17(4):885-897
Background, aim and scope
The importance of groundwater for human life cannot be overemphasised. Besides fulfilling essential ecological functions, it is a major source of drinking water. However, in the industrial area of Bitterfeld, it is contaminated with a multitude of harmful chemicals, including genotoxicants. Therefore, recently developed methodologies including preparative capillary gas chromatography (pcGC), MOLGEN-MS structure generation and mutagenicity prediction were applied within effect-directed analysis (EDA) to reduce sample complexity and to identify candidate mutagens in the samples. A major focus was put on the added value of these tools compared to conventional EDA combining reversed-phase liquid chromatography (RP-LC) followed by GC/MS analysis and MS library search. 相似文献886.
Virender K. Sharma Nigel J. D. Graham Xiang-Zhong Li Bao-Ling Yuan 《Environmental science and pollution research international》2010,17(2):453-461
Background, aim and scope
Photocatalytic oxidation using UV irradiation of TiO2 has been studied extensively and has many potential industrial applications, including the degradation of recalcitrant contaminants in water and wastewater treatment. A limiting factor in the oxidation process is the recombination of conduction band electrons (e − cb) with electron holes (hvb+) on the irradiated TiO2 surface; thus, in aqueous conditions, the presence of an effective electron scavenger will be beneficial to the efficiency of the oxidation process. Ferrate (FeO42−) has received much recent attention as a water treatment chemical since it behaves simultaneously as an oxidant and coagulant. The combination of ferrate [Fe(VI)] with UV/TiO2 photocatalysis offers an oxidation synergism arising from the Fe(VI) scavenging of e − cb and the corresponding beneficial formation of Fe(V) from the Fe(VI) reduction. This paper reviews recent studies concerning the photocatalytic oxidation of problematic pollutants with and without ferrate. 相似文献887.
K. Hund-Rinke K. Schlich A. Wenzel 《Umweltwissenschaften und Schadstoff-Forschung》2010,22(5):517-528
Abstract
Purpose Little is known about the ecotoxicity of nanomaterials and there are no specific guidelines for sample preparation and testing.
We set out to establish whether the method used to prepare TiO2 dispersions had a significant impact on aquatic ecotoxicity. We also followed the formation of agglomerates during the incubation
period. 相似文献
888.
Pesticide transport models commonly assume first-order pesticide degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch degradation data and mini-column experiments at lower flow rate. The study suggested that first-order degradation models may underestimate risk of pesticide leaching if the pesticide degradation potential needs amplification during degradation. 相似文献
889.
Jaana Bäck Hermanni Aaltonen Heidi Hellén Maija K. Kajos Johanna Patokoski Risto Taipale Jukka Pumpanen Jussi Heinonsalo 《Atmospheric environment (Oxford, England : 1994)》2010,44(30):3651-3659
Soils emit a large variety of volatile organic compounds. In natural ecosystems, measurements of microbial volatile organic compound (MVOC) exchange rates between soil and atmosphere are difficult due to e.g. the spatial heterogeneity of the belowground organisms, and due to the many potential sources for the same compounds. We measured in laboratory conditions the MVOC emission rates and spectra of eight typical fungi occurring in boreal forest soils. The studied species are decomposers (Gymnopilus penetrans, Ophiostoma abietinum), ectomycorrhizal (Cenococcum geophilum, Piloderma olivaceum, Suillus variegatus, Tomentellopsis submollis) and endophytic fungi (Meliniomyces variabilis, Phialocephala fortinii). The MVOC emissions contained altogether 21 known and 6 unidentified compounds whose emission rates were >0.1 μg g(DW)?1 h?1. The most abundant compounds were the short-chain carbonyl compounds (acetone and acetaldehyde). The greatest carbonyl emissions were measured from P. olivaceum (1.9 mg acetone g(DW)?1 h?1) and P. fortinii (0.114 mg acetaldehyde g(DW)?1 h?1). Terpenoid emissions (isoprene, mono- and sesquiterpenes) were detected from some fungal cultures, but in relatively small amounts. We conclude that soil micro-organisms can potentially be responsible for significant emissions of volatiles, especially short-chain oxygenated compounds, to the below-canopy atmosphere. 相似文献
890.