Quality evaluation and stability index determination of Qom rural drinking water resources

Corrosion and scaling are among the problems that despite science advancement, water facilities are still faced it. Corrosion lead to financial and health losses on water supply system and consumer, scaling also causes clogging and head loss in water supply network. Therefore, the aim of this study is to determine the corrosion and scaling potential of Qom villages water supply sources. In cross-sectional study 100 samples in 12 months from 2011 to 2012 were collected to verify the water quality according to 1053 standard of Institute of Standards and Industrial Research of Iran (ISIRI). Then water corrosion and scaling were studied using Langelier, Ryznar, Aggressive and Puckorius indexes. The results showed that the Langelier index, Reynar index, aggressive or corrosion index and index Puckorius were -1.62 (±0.11), 10.5 (±0.17), 12.03 (±0.14) and 9.92 (±0.13) respectively. Physical and chemical parameters of the water showed that the mean pH, TDS, total hardness, turbidity, calcium, magnesium, fluoride, sodium, ammonia, phosphate, and chloride were 7.27, 1205.29 mg/L, 435.661 mg/L CaCO3, 0.747 NTU, 132.29 mg/L, 25.58 mg/L, 0.68 mg/L, 245.50 mg/L, 0.015 mg/L, 0.17 mg/L and 231.22 mg/L respectively. The amounts of color, TDS, turbidity, pH, calcium, magnesium, fluoride andammonia in the study areas are in satisfactory and acceptable status compared to the internal standard but the amount of phosphate, hardness and chloride in this area were exceeded from permissible limit. Comparison of four stability index also showed that water conditions in all parts of this study are located in corrosive range.