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151.
采用SPSS软件,对2003年01月至2004年12月期间,倒天河水库和利民水库逐月水质监测数据进行数理统计分析,结果表明毕节市饮用水水质污染有较明显的季节变化和空间差异;且不同污染物对水体污染的贡献率各不相同,总磷和粪大肠菌群所占份额最大,方差累积贡献率达77%。在此基础上,利用加权综合污染指数对水体水质污染现状进行综合评价,结果显示倒天河水库和利民水库,水质污染总体较轻.饮用水水质符合《地表水环境质量标准(GB3838—2002)》中Ⅲ类水质标准;最后提出加大水环境保护的建议。  相似文献   
152.
Background & aim: To investigate and analyze the elements pollution in the extremely high tumor risks residents in the Chaoshan littoral, southern China. Methods: 19 elements including Cr, Mn, Ni, Sr, Pb, Zn, Co, Sn, Th, Tl, Se, Hg, Cu, Mo, Cd, Sb, U, Ge, As, and Al were measured from 145 hair samples of residents from the high-risk Nanao Island (mortality of cancer 173-156/106 in recent 30 years), Shantou high-risk village (mortality of cancer 230.4/106 in recent three years), and two controls Shanwei (mortality of cancer 32/106 in 1970s) and Meizhou Hakka (incidence of cancer 103/106 ) using AAS, AFS, ICP-MS methods collaborated with Beijing University. And 21 samples of water, 18 samples office from the Nanao Island, Shantou high-risk village, and other low-risk controls were measured using the same methods. Results: The element analysis showed that levels of CD, PB in the Shantou high-risk village were the highest, Hg, MN, SR, SB, TH, U on the Nanao Island were the highest in hairs. Conclusions: It is indicated that there occurred elements pollution among the local high-risk population.  相似文献   
153.
Permeable Reactive Barrier (PRB) is an emplacement of inert material (s) in the subsurface, designed to intercept a contaminated plume, provides a preferential flow path through the reactive media, and transforms the contaminant into environmentally acceptable forms to attain concentration remediation goals at the discharge of the barrier. The phenomena, which help in remediation within PRB, are adsorption/sorption, precipitation, oxidation/reduction and biodegradation. Various materials like zero-valent iron, zero-valent bi-metals, natural zeolites, organic carbon, fly ash, zeolites, limestone, activated alumina, apatites, etc. have been tried by many researchers to remove organic and inorganic contaminants. In USA, Canada, and many European countries commercial full-scale and pilot scale PRBs are successfully working. The design and installation of full scale PRBs needs laboratory treatability and dynamic flow column experiments? The concept of PRB is being applied to treat contaminated surface water in the Katedan industrial area, Hyderabad, India. National Geophysical Research Institute (NGRI), Hyderabad, India, conducted systematic studies in collaboration with Norwegian Geotechnical Institute (NGI), Norway, to develop PRB technique to decontaminate the surface water pollution due to industrial effluent. A site assessment study in the Katedan Industrial Area, were carried out and water, soil and sediment from the lakes of the area were found to be polluted with high concentrations of heavy metals like As, Pb, Cr, Cd, Ni, etc. Adsorption studies at NGRI with synthetic samples and in-situ industrial effluent using different reactive media for removing contaminants like arsenic, chromium, cadmium, copper, nickel, lead and zinc have been carried out and yielded satisfactory results. The performance of zero-valent iron and limestone is encouraging in removing As,  相似文献   
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采用紫外分光光度法测定了24.0℃时苯和甲苯在CH3COONa,(NH4)2SO4,MgSO4,Na2SO4和Na2CO3水溶液中的活度系数(f),它们的lgf-Cs关系符合Setschenow盐效应公式,计算了苯和甲苯在上述5种盐水溶液中的盐析系数。  相似文献   
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A simple and rapid procedure to extract organochlorine pesticides (OCPs) from sediments by means of microwave energy is proposed. Sediment samples were irradiated with microwaves in a closed vessel system while immersed in hexane-acetone (1 : 1, v/v). The sample extracts were cleaned up using solid phase extraction with Florisil as adsorbent. Pesticides were eluted with hexane-ethyl acetate (80 : 20, v/v) and determined by gas chromatographic separation with electron capture detection. Three oven programs were assayed with two different solvent mixtures in order to achieve adequate experimental conditions for the complete extraction of organochlorine pesticides from the matrix. Different variables such as the composition of extraction solvent,  相似文献   
160.
Sulfates are a main constituent of aerosols, which sulfate aerosols, it is necessary to determine what can cause various environmental problems sulfate ions are contained in these aerosols In the evaluation of the influence of In this study, sulfur K-edge XANES was used to determine sulfate species present in size-fractionated aerosol particles based on the post-edge structure after the main absorption peak in the XANES region. Aerosol samples were collected as part of the Japan-China joint project, "Asian Dust Experiment on Climate Impact" using a low-volume Andersen-type air sampler. XANES was measured at Beamline BL-9A at Photon Factory, Japan. A comparison of the XANES spectra of reference sulfate materials and aerosol samples collected in Tsukuba in Japan clearly showed that (NH4)2SO4 was the main sulfur species in particles with a smaller diameter and gypsum was the main sulfur species in particles with a larger diameter. A simulation of the XANES spectra by reference materials allows us to obtain the quantitative mixing ratios of the different sulfate species present in the aerosol samples. The presence of minor sulfur species other than (NH4)2SO4 and gypsum at the surface of mineral aerosols is suggested in our simulations and by a surface-sensitive conversion electron/He-ion yield XANES. In the absence of a contribution from a large dust event, the mole concentration of gypsum in the mineral aerosol fraction determined by XANES is similar to that of Ca which is determined independently using ion chromatography. This shows that the Ca and sulfate in the mineral aerosols are present only as gypsum. Considering that calcite is the main Ca mineral in the original material arising from an arid and semi-arid area in China, it is strongly suggested that gypsum is formed in aerosol during its long-range transportation by a reaction between calcite and sulfate ions.  相似文献   
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