تأثير فاضلاب هاي شهري بر خصوصيات هيدروشيميايي منابع آب شرب شهر قم

The effect of urban sewage on hydrochemical characteristics of Qom drinking water wells

In other to assessment of hydrogeochemical characteristics of Qom drinking water wells 80 water samples were collected from 24 wells in four periods during 1386. Concentration of major constituents (HC03,cr,S02_,Ca2+,Mg2+,K+and Na+), nitrate, ammonium, electrical conductivity and total dissolved solid have been measured. Groundwater type of this region is Na+ -cl_(S02_) and facies variation of groundwater has not changed because of low extent of study area. Results of cluster analysis show that the factors controlling quality of groundwater are including dissolution of halite and gypsum in Qom plane and leakage from pollution sources. Principle component analysis of ground water samples explains about 77 percent of groundwater quality variation is controlled by two main factors. About 60 percent of water quality variation related to dissolution of evaporates rocks which have been explained by PCI and 17 percent of water chemical component variation related to seepage of pollutant source and interpreted by PC2. Meanwhile intensive increase in concentration of nitrate and ammonium is caused by urban sewage. The maximum concentration of nitrate during 1386 is about 124 mg/1 that related to N-2. The other reason for effect of urban sewage is concentration of 1.6 mg/1 ammonium in water samples.