سلامت و محیط (Oct 2011)
Study of Nitrate Reduction from Water Using Nanosized Iron
Abstract
Background and Objectives: New studies indicate that nitrate concentration in groundwater is increasing in most cities. High concentrations of nitrate in water increase the potential health risk in the community and the environment. In infants, No3 _ is reduced to No2 _, which combines with hemoglobin in the blood to form met hemoglobin leading to blue-tinged blood for babies under six months old in particular ,Namely, so-called ‘‘blue baby syndrome'' and it also produce carcinogenic compounds . Therefore high nitrate concentration is important. The aim of the present study is removing nitrate from water using zero_valent iron.Materials and Methods: Analyses were conducted on synthetic samples. These samples were analyzed considering reaction times, pH, initial nitrate and sulfate concentration.Results: Results showed that at Nitrate with an initial concentration of 200mg L1- after 60 min of reaction at pH(s) 7, 6 and 5 about 67.8%, 72.5 % and 88% was reduced, respectively in concentration of 100 and 300 mgL- (pH=6) the removal efficiency is 60 and 83 percent, respectively. In sodium sulfate and nitrate with concentration of 300, the removal efficiency reached from 72 to 70 percent. Conclusion: Results show that the initial pH is important to achieve maximum efficiency of nitrate removal. So the lower pH levels increases removal efficiency of nitrate. All of the experiments indicated that removal is the highest in the first 5 min. Generally with an increasing initial nitrate concentration the removal efficiency of nitrate increases.
