بررسی آلودگی احتمالی نیترات در آب زیرزمینی آبخوان دشت تبریز

چکیده مقاله

The high concentration of nitrate in water is one of the pollutants in groundwater.In recent years due to increase of wastewater and agriculture and urban development,its amount in water sources is increasing. High nitrate concentration in potable water is dangerous for kids in view of sanitary and causes “Methaemoglobinaemia” or “Blue baby syndrome”. The aim of this research is measuring of the nitrate concentration in Tabriz Aquifer and comparing it with common standards. In order to ,six sample from Tabriz Aquifer were tested by using spectrophotometric methods in the chemistry lab of Eastern Azarbaijan Province Water Authority. The final results were studied and analyzed by statistic methods and Geographic Information System(GIS). The results of this study demonstrated the average minimum concentration of nitrate in Tabriz Aquifer is [10 mg/l], although average maximum concentration of nitrate is [80 mg/l] in [2007 & 2008]. Temporal and spatial variations of nitrate in Tabriz Aquifer is salient. According to geological maps and land use and nitrate correlation coefficient diagrams with chemical parameters such as sulfate ,chloride and electric conductivity(Ec) and precipitation diagrams in [2006,2007,2008 & 2009] indicated contamination of groundwater by nitrate is result of overdraft of groundwater and use of it in industrial ,urban and agricultural centers. Also nitrate pollution is due to discharge of industrial sewage ,urban and agriculture wastewater to penetrating wells and surface waters lead to/seepage to groundwater. According to the results , nitrate concentration in many areas of Tabriz Aquifer is more than standard of Iran and standard of Industry Research Institute. Because of health threats of high nitrate ,some basic performance should be done such as reduction of consuming nitrogen fertilizers, decrease overdraft of groundwater ,change of cultivation pattern, cultivation of plants that are compatible to water shortage, treatment of sewage and industrial, agriculture and urban wastewater is also necessary.