Survey of scaling and corrosion potential in drinking water resources of Shahrood city by using stability indexes in 2013

Corrosion and scaling are the main problems that water facilities still face with them. Corrosion can caused great financial losses and health damage to the system, and consumers. Blockages and pressure drop in the network are another disadvantage of scaling. The aim of present study was to determine the corrosive and scaling potential in drinking water resources of Shahrood city.
This crosses-sectional study was conducted over 4 seasons in 2013 years. 1104 samples were examined using Langelier (LSI), Rayznr (RSI), aggressive (AI) and Pokurious (PSI) indices to determine the corrosive and scaling potential in drinking water resources of Shahrood city. To compare the mean values of each indices, the results were analyzed using t-test.
The results indicate that the drinking water resources of Shahrood according to the Langelier index equals -1.03 with a standard deviation of 0.11, according to Rayznr index equals 9.72 with a standard deviation of 0.17, based on Aggressive index equals 12.10 with a standard deviation of 0.14, based on Pokurious index equals 9.59 with a standard deviation of 0.13 respectively. The difference between the mean values of the four studied seasons also were significant. P-value Comparison of four indices and obtained results showed that drinking water resources in Shahrood was corrosive, therefore, it is suggested that the city's water resources should constantly assessed and try adjusting the pH and control of other affecting factors on the corrosion such as chloride, dissolved oxygen and sulfate concentrations to reduce corrosion.