Lantian County, Northwest Of Underground Drinking Water Chemistry Characteristics And Quality Assessment

The drinking water of rural area resident source of water comes from groundwater mainly,and the quality of that affects people's health directly.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 Lantian county in the paper,we analysed the contents of groundwater element change characteristics and the cause of the elements exceed the accepted figure in every sample point of the general physiognomy of Lantian county,revealed the changing characteristic of element contents of the drinking water in different kinds of physiognomy.76 groundwater samples from different places and different times had been sampled from 3 different physiognomy types.We have carries out pH value, conductivity, conventional ions, arsenic, mercury, selenium and so on,11 kinds in total.The pH value and the conductivity were measured by pH meter and conductivity meter;The conventional ions were measured by Ion Chromatography;the arsenic,the mercury,the selenium measured by the Atomic Fluorescence Sectrometry.Analysis results shows that F,As,Hg and nitrate contents going beyond standard in the drinking water of this area.Nitrate go beyond standard rate is higher,reached 21% and 29%,respectively.the elements Hg,F and As take second place,going beyond standard rate is 9.2%,2.6%,2.6% in March,respectively;going beyond standard rate is 3.9%,2.6% in September,respectively.The others elements have not gone beyond the standard or have not been found.The content of nitrate in drinking water go beyond the standard is more serious, the valley terrace and southern plateau of the most serious. Human activity is the main cause excessive levels of nitrate, mainly in the production and life of the excessive use of pesticides and fertilizers, garbage thrown away and stacking at will, indiscriminate discharge of sewage.The distribution region going beyond the standard from Hg element burning is analysed,it may be the distance of 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.According valuation by noted grade in GB/T14848-93, analysis and evaluation of water samples. And because this method is equivalent to treatment in the evaluation process of the evaluation factors, without taking into account the weight of the different pollution factors,we use the amended grade to account it.Contrasted the results of the noted grade and the amended grage,the results of the noted grade can more objectively reflect the quality of the groundwater in this area. Geostatical methods applied in the northwest of Lantian County of underground drinking water quality,By special analyzing the pH value primarily to the higher in river valley areas in March;the northern mountains is mainly higher,and the river valley is lower in September.And the pH values were generally higher in March than in September.The content of F higher value were concentrated on the river valley of the two samples,and Arsenic in the northern mountains area higer then other regions;two samples with higher levels of nitrate content mainly in the river valley and southern plateau areas.Through the analysis of spatial distribution.by contrasted the value "f'and the amended value "f", we have verified that the amended value "f" could more objectively reflect the quality of the groungwater than the value "f" in this area.