Reducing Nitrate in Drinking Water Resources Using Natural Zeolite: A Case Study of Gorgan City, Golestan Province, Northern Iran

One of the drinking water resources has been selected for research based on chemical analysis with nitrate concentration of 53/7 mg/l in northern part of Gorgan city. In this research, natural zeolite has been used for reducing nitrate under laboratory conditions. The results indicated that natural zeolite reduced nitrate at about 13 mg/lit and also reduced hardness by passing 1 lit water through zeolitic bed (at about 1 kg) during a 30-minute time lag. In the chemical analysis, the pH of the water was 7/5 which chaned to 7/3 after passing through zeolitic bed. In this research, the hardness of raw water was 670 mg/l and the hardness was reduced 85 mg/lit in 40 grms zeolite with a time lag of 10 minutes whereas if zeolite weight was 160 grams, during a 30-minute timelag, the hardness would reduce to 175 mg/lit. Therefore, it can be concluded that natural zeolite could be used for reduction of nitrate in contaminated water wells all over the country.