Qian County, Shaanxi Province In Rural Areas, Underground Drinking Water Quality Analysis And Evaluation

The drinking water of rural area resident source of water comes from groundwater mainly.Resident's body general level of the health drinking water quality with local residents going hand in hand.Therefore,the actual meaning that we study the quality of drinking water of rural area and valuate the contaminated degree is important.Combining various physiognomy of Qianxian county of Shaanxi in the paper,we analysed the contents of groundwater element change characteristics and the cause in every sample point of the general physiognomy of Qianxian county, revealed the changing characteristic of element contents of the drinking water in different kinds of physiognomy.In this paper,we have carried out pH value,conductance,fluorine,calcium,sodium,iron, manganese,copper,zinc,nickel,arsenic,mercury,lead,chromium and cadmium,15 kinds in total,on 61 water samples of 3 different physiognomy types,the wells of different depth,.Result is demonstrated,Mn,Cd,Ni,Pb,Hg and F element contents going beyond standard in the drinking water of this area.F element and Hg element among them go beyond standard rate are higher, difference is reached 65.6%and 34.4%,the elements Cd and Mn take second place,going beyond standard rate is 11.48%and 4.9%respectively,besides,the elements Ni and Hg have a appearance to go beyond standard respectively,going beyond standard rate is 1.64%,the others elements have not gone beyond the standard or have not been found.The content of fluorine of drinking water samples in north mountain area all go beyond the standard,the content of fluorine in most of the central plain samples goes beyond standard,and the content of fluorine in southern tableland area is mainly qualified.The degree of fluorine contaminates has the trend decreasing by degrees from the north to the south.The 40 water samplings going beyond standard,the fluorin-speckle-tooth is popular in the most of this area, illness is lighter.The distribution region going beyond the standard from Hg element burning is analysed,it may be connected with sigmatism such as local pesticide and chemical fertilizer.The distance of individual central area sampling and industrial park is closer,the industrial sewage of these factories was discharged to water channel and rivers without disposal.Local residents commoniy irrigated cultivated land by contaminated water several years ago.Besides,the depth of hided groundwater is very an important factor to affect Hg value.North area and central area hide more shallow than the south area,so north area and central area is higher than the latter as a whole in Hg value.As we are equal to treat various contaminate factors contaminating a factor in the process of valuation by noted grade in GB/T 14848-93,any value factor "F_i" is high that makes the grading value synthetically be higher,considered the weight of contaminating factor's diversity,we should not treat various contaminate factors "F_i" value with a same grade in different ways,adopt the amended grade to account it.Contrasted the results of the noted grade and the amended grade,the results of the noted grade can more objectively reflect the quality of the groundwater in this area.As we have analysed the pictures of Appliance of surfer8.0 to drawing drinking water quality series pictures of constant value line of Qianxian county,we find that fluorine thickness and pH value of the samples the north mountain area and the central plain have obvious correlativity.The Hg thickness and well-depth of the samples of the central plain and the south tableland area have obvious correlativity,the human being activity brings Hg beyond standard mainly by analyse.Observed and analysed the picture of constant value line to sampling is analysed,we found fluorine thickness value and the value F constant value line having obvious correlativity.By contrast ed the value "F" and the amended value "F′",we have verifyed that the amended value"F′"could more objectively reflect the quality of the groundwater than the value "F"in this area.Appraising result indicated,As the depth(45～200m) of the wells of the south loess tableland are aand some areas is deeper than other places.The water quality rank in the place displays certain correlativity with well-depth,and the deep loess tier in the south loess tableland area of Qianxian county can filtrate contamination preferably.