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991.
Ten halophilic Archaea (Haloarchaea) strains able to degrade aromatic compounds were isolated from five hypersaline locations; salt marshes in the Uyuni salt flats in Bolivia, crystallizer ponds in Chile and Cabo Rojo (Puerto Rico), and sabkhas (salt flats) in the Persian Gulf (Saudi Arabia) and the Dead Sea (Israel and Jordan). Phylogenetic identification of the isolates was determined by 16S rRNA gene sequence analysis. The isolated Haloarchaea strains were able to grow on a mixture of benzoic acid, p-hydroxybenzoic acid, and salicylic acid (1.5 mM each) and a mixture of the polycyclic aromatic hydrocarbons, naphthalene, anthracene, phenanthrene, pyrene and benzo[a]anthracene (0.3 mM each). Evaluation of the extent of degradation of the mixed aromatic hydrocarbons demonstrated that the isolates could degrade these compounds in hypersaline media containing 20% NaCl. The strains were shown to reduce the COD of hypersaline crude oil reservoir produced waters significantly beyond that achieved using standard hydrogen peroxide treatment alone. 相似文献
992.
The effect of polarity on the oxidation of Hg0 was examined in the presence of O2 via a pulsed corona discharge (PCD). The experimental result showed no difference in the energy yield of Hg0 oxidation at both positive and negative PCDs (∼8 μg Hg W h−1 at following conditions: total flow rate = 2 L min−1 (Hg0 = 50 μg N m−3, O2 = 10%, and N2 balance), temperature = 150 °C, and specific energy density = 5-15 W h N m−3). This suggests that the positive PCD process used to control gaseous air pollutants may play an essential key role in Hg0 oxidation because it consumes enough energy (∼15 W h N m−3) but an electrical precipitator could not because it consumes less energy (∼0.3 W h N m−3) to oxidize Hg0. 相似文献
993.
Nonylphenolic compounds (NPs), coprostanol (COP), and cholestanol, major contaminants in industrial and domestic wastewaters, were analyzed in creek water, wastewater treatment plant (WWTP) effluent, and sediment samples from artificial Lake Shihwa and its vicinity, one of the most industrialized regions in Korea. We also determined mass discharge of NPs and COP, a fecal sterol, into the lake, to understand the linkage between discharge and sediment contamination. Total NP (the sum of nonylphenol, and nonylphenol mono- and di-ethoxylates) were 0.32-875 μg L−1 in creeks, 0.61-87.0 μg L−1 in WWTP effluents, and 29.3-230 μg g−1 TOC in sediments. Concentrations of COP were 0.09-19.0 μg L−1 in creeks, 0.11-44.0 μg L−1 in WWTP effluents, and 2.51-438 μg g−1 TOC in sediments. The spatial distributions of NPs in creeks and sediments from the inshore region were different from those of COP, suggesting that Lake Shihwa contamination patterns from industrial effluents differ from those from domestic effluents. The mass discharge from the combined outfall of the WWTPs, located in the offshore region, was 2.27 kg d−1 for NPs and 1.00 kg d−1 for COP, accounting for 91% and 95% of the total discharge into Lake Shihwa, respectively. The highest concentrations of NPs and COP in sediments were found in samples at sites near the submarine outfall of the WWTPs, indicating that the submarine outfall is an important point source of wastewater pollution in Lake Shihwa. 相似文献
994.
Occurrence and distribution of pharmaceuticals in surface water, suspended solids and sediments of the Ebro river basin, Spain 总被引:3,自引:0,他引:3
The occurrence of 43 pharmaceuticals belonging to predominant therapeutic classes and their distribution in surface water, suspended solids and sediments has been investigated in the Ebro river basin in the Northeast of Spain. WWTP effluents were found to be a main source of contamination and the spatial distribution was affected by the river flow at the sampling point and corresponding dilution factor, resulting in higher concentrations and higher loads in small tributary rivers than in the Ebro river. The study showed that some compounds are preferentially found bound to suspended solids and not detected in river water. Generally, compounds with basic characteristics (pKa > 7) showed higher tendency to bind to suspended solids. The sediment samples generally presented lower concentrations than suspended solids. 相似文献
995.
Quantification of nitrate leaching from German forest ecosystems by use of a process oriented biogeochemical model 总被引:1,自引:0,他引:1
Kiese R Heinzeller C Werner C Wochele S Grote R Butterbach-Bahl K 《Environmental pollution (Barking, Essex : 1987)》2011,159(11):3204-3214
Simulations with the process oriented Forest-DNDC model showed reasonable to good agreement with observations of soil water contents of different soil layers, annual amounts of seepage water and approximated rates of nitrate leaching at 79 sites across Germany. Following site evaluation, Forest-DNDC was coupled to a GIS to assess nitrate leaching from German forest ecosystems for the year 2000. At national scale leaching rates varied in a range of 0–>80 kg NO3–N ha−1 yr−1 (mean 5.5 kg NO3–N ha−1 yr−1). A comparison of regional simulations with the results of a nitrate inventory study for Bavaria showed that measured and simulated percentages for different nitrate leaching classes (0–5 kg N ha−1 yr−1:66% vs. 74%, 5–15 kg N ha−1 yr−1:20% vs. 20%, >15 kg N ha−1 yr−1:14% vs. 6%) were in good agreement. Mean nitrate concentrations in seepage water ranged between 0 and 23 mg NO3–N l−1. 相似文献
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由于小型景观水体的体量和再生水补水措施的施行,其水质随环境和入水水质的变化和富营养化过程较大型水体快。由EFDC模型和WASP模型耦合建立小型浅水景观湖生态动力学模型,用实测水质数据进行参数率定与验证,可实现小型景观水体水质变化趋势的模拟,为水质管理提供决策支持。在此基础上,对民主湖在几种水质保障方案下1年的水质变化进行了模拟预测和对比,结果表明,作为富营养化程度表征的叶绿素a在空间和时间分布上均存在一定的规律性,夏季由于温度升高,叶绿素a浓度较高,说明藻类等浮游植物迅速增殖,是水质恶化水华暴发的高发期,而采取加大湖水水力循环和改善入口水质的控制方案,可使水质得到良好保障。 相似文献