| The Changchun City, capital of Jilin Province, is situated in the central part ofNortheast Plain of China. The population is about 6×106. The City has witnesseda rapid urbanization and economic growth over the last ten years. This has lead torapid increase in population, industries and consequently a deficit in water supply.In addition many environmental problems such as water pollution, solid wastesand sewage effluents management have been increased. Groundwater assuresabout 45 % of total water supply of the city. Drinking was mostly served bysurface water from Shitoukoumen and Xinlicheng reservoirs located in the eastand south of the city. However, with the development of urban construction thegroundwater especially from deep boreholes is also used for drinking purpose insuburban areas. Most of groundwater pollutions researches done in ChangchunCity remain the annual or sporadic reports provided by the Water Resourcesoffices or Environmental agencies. In light of the above-mentioned problems,this research on groundwater pollution was conducted in Changchun City from2002-2004. The main methodologies used to carry out this research include deskstudy, field works, laboratory works (about 2 months fieldwork, and 2 yearslaboratory works) .The field works include wells water, surface water and wastedumped sites monitoring inventory and geographical locations recording usingGPS. The GIS and statistical software were used for mapping and modelingworks. From the research, it was clear that, industrial effluents and leachate fromsolid wastes disposal sites were the major sources of groundwater pollution inChangchun City therefore NO3 TFe and Mn2+ ions were higher in groundwater - ,monitoring wells near waste dumped sites. BOD, Permanganate Index, NO3 TFe - ,and Mn2+ were higher in surface water bodies inside the City. The surfacemonitoring sites, far from the city especially Shitoukoumen and Xinlichengreservoirs were less impacted by the pollution. The median concentrations values of most of chemical species monitoredfrom 1991 to 1998 especially for the shallow aquifer data were higher than thestandard for drinking water. The determination of hydrochemical facies type is a tool to controlgroundwater from pollution any deviation from background water facies can berelated to pollution. The most used tool to determine water quality is by plottingon Piper diagram, which determine 4 classes of water facies for both shallow anddeep groundwater: (1) HCO3 -Ca2+ and HCO3 -Ca2+, Mg2+ or HCO3 -Mg2+, Ca2+; - - -(2) SO4 -Ca2+and SO4 -Ca2+, Mg2+; (3) Cl--Ca2+; and (4) CO3 - Na+. Because of 2- 2- 2-Piper diagram does not have any geographical references, a GIS mapping modelbased on the piper diagram construction references were used here for mappingthe groundwater chemical type. The maps of geochemical facies showed thatHCO3 water type occupied the largest area of the city for both shallow and deep -groundwater data. Statistical bivariate analysis showed strong positive coefficient of correlationfor NO3 with most of the major ions specially Ca2+, Cl-, for both shallow and -deep groundwater from 1991 to 1998. Since correlation analysis revealssimilarities in the behavior of pairs of ions, and does not conveniently identifygroups of ions that behave similarly, factor analysis is carried out to help inhydrogeochemical interpretation of the data. The Factor analysis showed that 141Ca2+, Cl-, NO3 , Mg2+, TH and TDS were frequently loaded in Factor I which -represents in most of the cases more than 30% of total variances and termed as"Pollution Factor" .The results showed that the...
|
PDF Full Text Request