Evaluation of Corrosion and Scaling Potential of a Water Treatment Plant

Background & Aims of the Study: We evaluated corrosion and scaling potential of water treated by “Takab city (Western Iran) water treatment plant (called Chahar Tagh facilities)” using field observation of water treatment plant, and study of physical and chemical parameter values of water. In this cross-sectional study, during a 10-month period (from January to October 2012) in each month, 15 grab samples with 2 to 3 L of water were collected for analysis. Some physical and chemical parameters such as temperature, pH, total dissolved solids, calcium and magnesium hardness, calcium and magnesium ions concentration, total alkalinity, bicarbonate concentration and electrical conductivity were measured. The corrosion and scaling potential of water were calculated by Langelier saturation index (LSI), Risnar index (RI), aggressive index (AI) and Puckorius scaling index (PSI). Values recorded for all physicochemical parameters were in acceptable standard levels. The calculated values of LSI index indicated slightly scale forming and corrosive, RI index showed heavy corrosion, AI index showed water is non-aggressive and based on PSI index results water is likely to dissolve scale. Based on LSI, RI, AI and PSI monthly indices results the water of water treatment plant showed a uniform quality of corrosion and precipitation potential. The results showed that values of all measured physical and chemical parameters were in the range of national and international standards. Based on LSI and AI indices results, water tends to scale forming while based on RI and PSI indices results water tend to be corrosive.