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151.
植物SOD活性变化与其抗污能力的关系   总被引:4,自引:0,他引:4  
研究了模拟酸雨、SO2单独与复合污染对水杉、杉木、龙柏3种抗污能力不同的植物SOD活性、细胞汁酸度、细胞膜透性的影响。结果表明,SOD的活性经污染后变化规律在不同植物有所不同,而这种变化与其抗污能力有关。SOD活性升高者,其抗污能力强,反之则弱,与本底值大小无关。  相似文献   
152.
Improved predictions on the fate of organic pollutants in surface environments require a better understanding of the underlying sorption mechanisms that control their uptake by soils. In this study, we monitored sorption of nine aromatic compounds with varying physicochemical properties (hydrophobicity, electron-donor/acceptor ability and polarity), including two polycyclic aromatic hydrocarbons, two chlorobenzenes, two nitroaromatic compounds, dichlobenil, carbaryl and 2,4-dichlorophenol in aqueous suspension of four surface soils of eastern China. The tested soils were characterized with respect to organic carbon (OC) content, black carbon content, mineralogy, morphology and size fraction to assess the role of the diverse soil characteristics in sorption. The results of this study show that not only the solute hydrophobicity and the OC content of soil are important to the retention of organic pollutants, but also the solute molecular structure and the soil nature.  相似文献   
153.
Lin YJ  Liu HC  Hseu ZY  Wu WJ 《Chemosphere》2006,64(4):565-573
This study was designed to investigate the transportation, distribution, and bioaccumulation of PCBs in various environmental media and compartments using an ecologically simulated growth chamber. Spatial and temporal trends of PCBs in the growth chamber were discussed. The release of PCB congeners in soil was affected by the amount of rainfall with the transporting direction moving away from PCBs contaminated point. Two pathways of PCBs accumulation in plants were the uptake of roots and the deposition on shoots/leaves. There were 29 PCB congeners been found in the lalang grass. Higher concentrations of lower chlorinated PCBs were identified than higher chlorinated PCBs because of relatively higher vapor pressure for lower chlorinated congeners. After 10months of monitoring, PCBs were detected in water samples which were contributed by the release of PCBs from leached soil. Analysis of sediment showed that the percentages of low- and mid-chlorinated biphenyls were decreased 1% and 13%, respectively compared to the increase (14%) of high-chlorinated biphenyls. The increase of high-chlorinated PCBs was possibly caused by their low hydrophilicity which had resulted higher adsorption rate in sediment. All of five species of fish had been found significant amount of PCBs accumulation ( summation operatorPCBs: 21.7-102.1 microg/g-lipid). The concentrations of PCBs in fish were varied significantly among species. The range of bioaccumulation factors (BAFs) among different species of fish could be as much as 5 times depending on the consumption habits of fish. The mass balance of PCBs distribution in the growth chamber was also discussed.  相似文献   
154.
155.
铁炭法处理高浓度难降解表面活性剂废水的研究   总被引:5,自引:0,他引:5  
就铁炭法对高浓度难降解拉开粉(阴离子表面活性剂)废水的处理效果进行了接近工业化的动态模型实验研究,结果表明酸化铁炭工艺对橡胶工业拉开粉废水具有显著的去除效果。在Fe:C=2:1,pH=4,停留时间60min,曝气量0.1m^3/h时,拉开粉(BX)和COD的总去除率分别约为80%和45%。  相似文献   
156.
He LY  Hu M  Huang XF  Zhang YH  Yu BD  Liu DQ 《Chemosphere》2006,62(10):1565-1573
Vehicle populations in China have been increasing sharply since 1990s. Vehicle emissions including various gaseous pollutants and particulate matter cause deterioration of air quality. However, measurements of particulate mater from on-road vehicles in China are scarcely reported, and thus the chemical compositions of particles emitted from vehicles in China are unknown. In this research, tunnel experiments were performed to measure PM2.5 in the Wutong tunnel, Shenzhen, China. Detailed PM2.5 chemical compositions, with organic compounds determined by GC/MS, in the tunnel were presented. Elemental carbon and organic matter composed 63% and 34% of the total PM2.5 mass in the Wutong tunnel, respectively. Alkanes, PAHs, hopanes, fatty acids, and dicarboxylic acids were the major identified organic compounds, and their source profiles in the PM2.5 in the Wutong tunnel were characterized. The comparisons of our measurements with those in the literature were also made to demonstrate the characteristics of the vehicle source profiles in the Wutong tunnel. The experimental results in this paper can improve understanding of particulate matter emitted from vehicles in China.  相似文献   
157.
In this study, a hybrid two-stage fuzzy-stochastic robust programming (TFSRP) model is developed and applied to the planning of an air-quality management system. As an extension of existing fuzzy-robust programming and two-stage stochastic programming methods, the TFSRP can explicitly address complexities and uncertainties of the study system without unrealistic simplifications. Uncertain parameters can be expressed as probability density and/or fuzzy membership functions, such that robustness of the optimization efforts can be enhanced. Moreover, economic penalties as corrective measures against any infeasibilities arising from the uncertainties are taken into account. This method can, thus, provide a linkage to predefined policies determined by authorities that have to be respected when a modeling effort is undertaken. In its solution algorithm, the fuzzy decision space can be delimited through specification of the uncertainties using dimensional enlargement of the original fuzzy constraints. The developed model is applied to a case study of regional air quality management. The results indicate that reasonable solutions have been obtained. The solutions can be used for further generating pollution-mitigation alternatives with minimized system costs and for providing a more solid support for sound environmental decisions.  相似文献   
158.
水处理工艺去除藻毒素的效果探讨   总被引:1,自引:0,他引:1  
探讨了饮用水处理的各工艺过程对藻毒素的去除作用,并根据前期已进行的实验对各工艺的优化组合进行了讨论,认为以气浮代替沉淀,并附之以粉末活性炭吸附预处理可有效地去除藻毒素;对没有条件改造沉淀池的水厂可暂时采用预氯化和粉末活性炭吸附组合的工艺也可达到较好的效果;对生物预处理工艺进行适当的强化,可达到对有机物、藻类、藻毒素等物质的有效去除.  相似文献   
159.
SO2的气相光催化氧化及催化剂的失活和再生研究   总被引:2,自引:0,他引:2  
在模拟大气环境中,紫外光照射以及纳米TiO2光催化剂的作用下,气相无机污染物SO2被完全氧化为SO3或H2SO4.本文提出了SO2的非均相光催化氧化机理,并得出光催化反应速率符合一级动力学过程;经过连续使用之后,TiO2的光催化活性降低,最后活性消失;经过水洗之后,失活的TiO2可以得到再生.失活的TiO2和新鲜的TiO2的IR和XPS光谱差异表明,失活的TiO2表面存在H2SO4,其被认为是使催化剂失活的成分.  相似文献   
160.
Gong R  Ding Y  Liu H  Chen Q  Liu Z 《Chemosphere》2005,58(1):125-130
In order to search for locally available and untried biomaterials in China with high removal capacity of heavy metals from wastewater, the feasibility of Spirulina maxima as biosorbent for lead removal and recovery from aqueous solution was investigated. The lead biosorption was studied by using intact biomass and pretreated biomass of S. maxima. The effects of operational conditions (e.g. pH, contact time, biomass concentration etc.) on lead biosorption were investigated. The biosorption was solution pH dependent and the maximum adsorption was obtained at a solution pH of about 5.5. The adsorption equilibrium was reached in 60 min. The biosorption followed the Freundlich isotherm model. The maximum removal ratios of lead were about 84% in intact biomass and 92% in pretreated biomass. The lead adsorbed could be desorbed effectively by 0.1 M nitric acid, EDTA and hydrochloric acid. The results in this study indicated that pretreated biomass of S. maxima was a promising candidate for removing lead from wastewater.  相似文献   
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