Determination of Nitrate and Nitrite concentrations in Groundwater Resources of Dehgolan City

Nitrate and nitrite ions are important pollutants of surface waters and groundwater resources which can have adverse effects on the health of consumers. Therefore the purpose of this study was determination of nitrate and nitrite concentrations in groundwater resources of Dehgolan City. Groundwater samples were collected from20 selected stations during before and after of fertilization periods in 2012. The samples are prepared according to APHA method and concentrations of nitrate and nitrite anions analyzed using spectrophotometer on the wavelengths of 420 and 543 nm respectively. All statistical analyses were performed using the SPSS statistical package. The results showed that mean concentrations of nitrate and nitrite anions in groundwater samples for before fertilization period were 8. 66±0. 97 and 0. 001±0. 0003 mg L-1، respectively، and for after fertilization period were 69. 20±8. 82 and 0. 013±0. 006 mg L-1، respectively. Also comparison of the mean concentration of nitrate in groundwater samples after fertilization period with Iran DOE permissible limits for drinking use showed that significant difference (p<0. 05). So that the mean concentration of nitrate significantly upper than permissible limits. According to the results of this study because of the mean concentration of nitrate significantly upper than permissible limits، therefore long-term excessive use of agricultural inputs and construction of polluting industries، can cause a threat to groundwater resources، and health of residents in this area.