AN EVALUATION OF WATER QUALITY FROM MOJEN RIVER, BY NSFWQI INDEX

Water quality index (WQI) is valuable and unique rating to depict the overall water quality status in a single term that is helpful for the selection of appropriate treatment technique to meet the concerned issues. The aim of the study was to evaluating water quality from Mojen River by Water Quality Index based on National Science Foundation (NSFWQI). For this purpose, samples were collected from stations at up, middle and downstream of Mojen River in Semnan province (the biggest river in region) in a 2 years interval of 2013-2014 years. Nine parameters namely Turbidity, Biochemical Oxygen Demand, Dissolved Oxygen, Fecal Coliform, nitrate, pH, temperature, total solids and total phosphate were considered to compute the index. Our findings highlighted the deterioration of water quality in the river due to industrialization and human activities. According to NSFWQI, the best condition was recorded in the Darkhaniab (Upstream) and the worst condition concerned the Pole (Midstream).