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261.
In this study two sites were selected in order to investigate groundwater contamination and spatial relationships among groundwater quality, topography, geology, landuse and pollution sources. One site is the Asan area, an agricultural district where pollution sources are scattered and which is mainly underlain by granite of Cretaceous age. The other site is the Gurogu area of Seoul city, an industrial district where an industrial complex and residential areas are located and which is mainly underlain by gneiss of Precambrian age. Groundwater samples collected from these districts were analysed for chemical constituents. An attribute value files of chemical constituents of groundwater and the spatial data layers were constructed and pollution properties were investigated to establish out spatial relationships between the groundwater constituents and pollution sources using geographic information systems (GIS).Relatively high contents of Si and HCO3
– in the groundwater from the Asan area reflect the effect of water–rock interaction whereas high contents of Cl–, NO3
– and Ca2+ in the groundwater from the Gurogu area are due to the pollution of various sources. The significant seasonal variation of SiO2, HCO2
– and Ca2+ contents, and that of Ca2+ content were observed in the Asan and the Gurogu areas, respectively. Seasonal variation of pollutants such as Cl–, NO3
– and SO4
2– was not observed in either area. Pollution over the critical level of the Korean drinking water standard has been investigated from 15 sampling sites out of 40 in the Asan area, and 33 sampling sites out of 51 in the Gurogu area. Pollution by NO3
–, Cl–, Fe2+, Mn2+, SO4
2– and Zn2+ in the groundwater from the industrial district (Gurogu area) and that of NO3
, SO4
2– and Zn2+ in the groundwater from the agricultural district (Asan area) were observed. The principal pollutant in both areas is NO3
–. Deep groundwater from the Asan area is not yet contaminated with NO3
– except for one site, but most of the shallow groundwater site occurring near the potential point sources is seriously contaminated. From the result of buffering analysis, it seems clear that factories and stock farms are the principal pollution sources in the Asan area. The groundwater from the Gurogu area has already been seriously polluted considering the fact of NO3
– contamination of deep groundwater. Chlorine pollution of shallow groundwater in the Gurogu area was also observed. Spatial relationship between pollution level and its source was clarified in this study by using GIS, which will be applicable to the effective management of groundwater quality. 相似文献
262.
用改良彗星试验检测工业废水的DNA损伤作用 总被引:2,自引:0,他引:2
采用改良彗星试验直接检测了多种工业废水不所引起的V79细胞DNA损伤。结果表明,所测的种各工业废话水均含有DNA损伤剂,能够诱发培养的V79细胞DNA链断裂,其中以制革厂不的DNA损伤作用最强。本研究显示出改良彗星试验在综合评价各种废水遗传毒性方面具有广阔的应用前景。 相似文献
263.
264.
Compound contamination and secondary ecological effects of Cd and As in soil-alfalfa ecosystems 总被引:11,自引:3,他引:11
CompoundcontaminationandsecondaryecologicaleffectsofCdandAsinsoil-alfalfaecosystems(ZhouQixing;GaoZhengmin)(InstituteofApplie... 相似文献
265.
H. Brandenburg L. van der Zwan M. G. J. Jahoda Th. Stunen J. W. Wladimiroff 《黑龙江环境通报》1991,11(9):685-690
Ninety-six women of advanced maternal age were interviewed about the way they obtained information on prenatal diagnosis and about how the decision was made as to what procedure was to be performed (transabdominal chorionic villus sampling (TA-CVS) or amnio-centesis). In the CVS group, women visited their physician or midwife earlier in pregnancy (mean 7.1 weeks) than those in the amniocentesis group (mean 10.7 weeks). The availability of prenatal diagnosis was not mentioned during the first antenatal visit in 55 per cent of women from the amniocentesis group as opposed to 25 per cent from the TA-CVS group. Approximately 40 per cent of women eligible for prenatal diagnosis did not receive any information from the referring body prior to counselling at our centre. Only 29 per cent of women who underwent amniocentesis had actually chosen this procedure; 71 per cent were too late to undergo TA-CVS at 12 weeks. It is concluded that information to the patient must be improved in order to ensure early referral for prenatal diagnosis. 相似文献
266.
Use of tree rings to investigate the onset of contamination of a shallow aquifer by chlorinated hydrocarbons 总被引:3,自引:0,他引:3
Oaks (Quercus velutina Lam.) growing over a shallow aquifer contaminated by chlorinated hydrocarbons were studied to determine if it was possible to estimate the approximate year that contamination began. The annual rings of some trees downgradient from the contaminant release site contained elevated concentrations of chloride possibly derived from dechlorination of contaminants. Additionally, a radial-growth decline began in these trees at approximately the same time that chloride became elevated. Growth did not decline in trees that contained smaller concentrations of chloride. The source of elevated chloride and the corresponding reductions in tree growth could not be explained by factors other than contamination. On the basis of tree-ring evidence alone, the release occurred in the late 1960s or early 1970s. Contaminant release at a second location apparently occurred in the mid- to late 1970s, suggesting that the area was used for disposal for at least 5 years and possibly longer. 相似文献
267.
Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in the Dutch Rhine-Meuse Delta that differed in level of contamination. Previously developed protocols for each bioassay were followed, which differed in sediment pretreatment, replication, and food availability. The Chironomus bioassay was conducted in situ, whereas the other two were conducted in the laboratory. The measured endpoints, survival and growth, were related to contaminant levels in the sediment and to food quantity in water and sediment.
Only the response of A. aquaticus in the bioassay was correlated with sediment contamination. Food availability in overlying water was much more important for C. riparius and E. virgo, thereby masking potential sediment contaminant effects. We conclude that growth of A. aquaticus was depressed by sediment contamination, whereas growth of E. virgo and C. riparius was stimulated by seston food quantity. We discuss that the trophic state of the ecosystem largely affects the ecological risks of contaminated sediments. 相似文献
268.
基于常熟河网原型调水实验和水功能区划,建立了感潮地区河网水量水质模型,对常熟河道水质降解系数及水环境容量进行了计算,并按照点源和面源对区域内污染源进行统计,在此基础上进行了常熟河网水污染物总量控制值和现状削减量的计算,为该地区的水污染防控提供了科学依据。 相似文献
269.
270.
Biodegradation of 2,4,6-trichlorophenol in the presence of primary substrate by immobilized pure culture bacteria 总被引:8,自引:0,他引:8
In this study, pure strains that are capable of utilizing 2,4,6-trichlorophenol have been isolated from the mixed culture grown on substrates containing chlorophenolic compounds. Studies have been carried out on the capability of these isolated pure strains in suspended and immobilized forms to decompose 2,4,6-trichlorophenol. Additionally, the influence of primary substrates (e.g., phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol) on the decomposition of 2,4,6-trichlorophenol by the isolated pure strains grown in immobilized form is also investigated. The results are: Through bacterial isolation and identification, three pure strains have been obtained: Pseudomonas spp. strain 01, Pseudomonas spp. strain 02 and Agrobacterium spp. Whether in suspended or immobilized forms, all strains have poor removal efficiencies of 2,4,6-trichlorophenol. However, addition of 200 mg/l phenol will enable the immobilized Pseudomonas spp. strain 01, and Pseudomonas spp. strain 02 to achieve 65% and 48% removal of 2,4,6-trichlorophenol, respectively. Addition of phenol will assist the immobilized Pseudomonas spp. strain 02 in achieving removal of 2,4,6-trichlorophenol but the removal efficiency is not good if the phenol concentration is too low. The optimum phenol concentration should be between 200 and 400 mg/l. 相似文献