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731.
水中微量甲基膦酸类化合物的树脂富集与GC/MS分析 总被引:3,自引:0,他引:3
本文使用三种阴离子交换树脂(即大孔弱碱型D-301-R,强碱型D-296,201X7)柱对水中微量甲基膦酸类化合物的富集方法进行了研究。含磷毒剂降解产物的水样用气相色谱/质谱法进行定性定量分析。结果表明,D-301-R阴离子交换树脂柱对甲基膦酸的富集回收率高于60%。 相似文献
732.
He S Feng Y Gu N Zhang Y Lin X 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3468-3473
Extensive production and application of γ-Fe2O3 magnetic nanoparticles (MNPs) has increased their potential risk on environment and human health. This report illustrates a genetic impact of γ-Fe2O3 magnetic nanoparticles (MNPs) on Escherichia coli (E. coli). After 3000-generation incubation with MNPs addition, obvious genomic variations were revealed by using repetitive extragenic palindromic PCR (rep-PCR) DNA fingerprint technique. The physicochemical interactions between MNPs and bacteria could be responsible for such genomic responses. It was revealed that Fe3+ concentration increased in the medium. Transmission electronic microscopy (TEM) and flow cytometry (FCM) analysis consistently demonstrated the occurrences of adsorption and membranes-internalization of MNPs outside and inside cells. Both increased Fe3+ ion and the uptake of MNPs facilitated Fe binding with proteins and DNA strands, resulting in enhancing the mutation frequency of E. coli. Our results would be of great help to assessing the potential impact of MNPs on human and environment. 相似文献
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735.
Shi X Gu A Ji G Li Y Di J Jin J Hu F Long Y Xia Y Lu C Song L Wang S Wang X 《Chemosphere》2011,85(6):1010-1016
Cypermethrin, a type II pyrethroid insecticide, is widely used throughout the world in agriculture, forestry, horticulture and homes. Though the neurotoxicity of cypermethrin has been thoroughly studied in adult rodents, little is so far available regarding the developmental toxicity of cypermethrin to fish in early life stages. To explore the potential developmental toxicity of cypermethrin, 4-h post-fertilization (hpf) zebrafish embryos were exposed to various concentrations of cypermethrin (0, 25, 50, 100, 200 and 400 μg L−1) until 96 h. Among a suite of morphological abnormalities, the unique phenotype curvature was observed at concentrations as low as 25 μg L−1. Studies revealed that 400 μg L−1 cypermethrin significantly increased malondialdehyde production. In addition, activity of antioxidative enzymes including superoxide dismutase and catalase were significantly induced in zebrafish larvae in a concentration-dependent manner. To further investigate the toxic effects of cypermethrin on fish, acridine orange (AO) staining was performed at 400 μg L−1 cypermethrin and the result showed notable signs of apoptosis mainly in the nervous system. Cypermethrin also down-regulated ogg1 and increased p53 gene expression as well as the caspase-3 activity. Our results demonstrate that cypermethrin was able to induce oxidative stress and produce apoptosis through the involvement of caspases in zebrafish embryos. In this study, we investigated the developmental toxicity of cypermethrin using zebrafish embryos, which could be helpful in fully understanding the potential mechanisms of cypermethrin exposure during embryogenesis and also suggested that zebrafish could serve as an ideal model for studying developmental toxicity of environmental contaminants. 相似文献
736.
Free atmospheric phosphine concentrations and fluxes in different wetland ecosystems, China 总被引:3,自引:0,他引:3
Han C Geng J Hong Y Zhang R Gu X Wang X Gao S Glindemann D 《Environmental pollution (Barking, Essex : 1987)》2011,159(2):630-635
Atmospheric phosphine (PH3) fluxes from typical types of wetlands and PH3 concentrations in adjacent atmospheric air were measured. The seasonal distribution of PH3 in marsh and paddy fields were observed. Positive PH3 fluxes are significantly related to high air temperature (summer season) and increased vegetation. It is concluded that vegetation speeds up the liberation of PH3 from soils, while water coverage might function as a diffusion barrier from soils or sediments to the atmosphere. The concentrations of atmospheric PH3 (ng m−3) above different wetlands decrease in the order of paddy fields (51.8 ± 3.1) > marsh (46.5 ± 20.5) > lake (37.0 ± 22.7) > coastal wetland (1.71 ± 0.73). Highest atmospheric PH3 levels in marsh are found in summer. In paddy fields, atmospheric PH3 concentrations in flourishing stages are higher than those in slowly growing stages. 相似文献
737.
Luo ZH Wu YR Pang KL Gu JD Vrijmoed LL 《Environmental science and pollution research international》2011,18(9):1653-1660
Purpose
Dimethyl phthalate esters (DMPEs) are a group of plasticizers commonly detected in the environment with potential adverse human health impact. The degradation of DMPEs by fungal systems has been studied to a limited extent, particularly by yeasts. In this study, a basidiomycetous yeast Trichosporon DMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated. 相似文献738.
环境中三甲胺的气相色谱测定 总被引:4,自引:0,他引:4
采用PEG20M30m×530μm弹性石英毛细管色谱柱分离,FID检测器检测。环境空气用水吸收,水样直接或顶空进样测定环境中的三甲胺。方法有较高的灵敏度和良好的线性关系,简便快速。 相似文献
739.
改进抽油机井“功率平衡”测试实现节能降耗 总被引:2,自引:0,他引:2
目前在抽油机井管理中普遍采用的平衡标准是"电流平衡",并认定电流平衡度在80%~120%之间时抽油机即为平衡。而真正判断抽油机平衡的标准是"功率平衡",即抽油机运行过程中,下冲程内电机平均功率与上冲程内电机平均功率相等。抽油机功率平衡既能实现节能目的,又能保证抽油机安全运行。从2008年7月开始率先在胜利油田进行抽油机功率平衡技术的试验及推广,2008年共调整抽油机功率平衡118井次,平均单日节电21.4kW.h,平均节电率9.90%,取得了良好的节能效果。 相似文献
740.
天然沸石处理富营养化水的生物基作用研究 总被引:7,自引:1,他引:6
采用实验室模拟封闭池塘水体的方法研究了天然沸石处理富营养化水的机理与方法,采用电镜等手段观察和研究了沸石生物膜的形态。结果表明,天然沸石是一种良好的生物基材料,具备生物膜功能的沸石对富营养化池塘水中的NH3-N和COD能保持长效和稳定的去除作用,两者的去除率分别为85%~88%和64%~73%。对磷的去除以吸附为主,去除率可达27%,吸附饱和后沸石失去除磷效果。天然沸石的吸附、离子交换和生物作用,能形成一个完整和谐的吸收消化系统,使天然沸石始终处于吸附未饱和状态,是沸石去除NH3-N和COD的重要机理。天然沸石来源广泛,价格不高,在富营养化池塘水净化中,具有效果持久、无二次污染和不影响水体景观的特点,在提高和改善水质的同时,对增强水生态系统的自净能力有利,是一种安全和纯生态的处理方法。 相似文献