Survey of Corrosion or Scaling Potential of Resources, Storage and Distribution of Water Supply System in Kian by using Langlier and Rizner Indexes

Corrosion ratio, Defined as the destruction percentage of a metal by chemical reactions, in other words, the measurement of an invasion of water to pipes and rusty equipment. The main focus of previous researches has been the economic aspects of corrosion, but recently, it seems that is necessary to study the other aspects of corrosion, such as aesthetic aspects. This study was achieved during the period of 1388–1389 by focusing on identification of corrosion ratio in Kian city. Seven points in Kian city (in Chahr Mahal va Bakhtiary province) were selected for sampling, (regarding the population density, area surface, and water distribution scheme). Temperature, calcium hardness ratio, CO2, alkalinity, TDS, SO4-2, Cl- and pH were measured. The analysis was based on the book of "standard methods for water and waste water examination" published in 2003. The results showed that the temperature and pH were the only parameters with the standard average. Calculation of Langlier and Rizner Indexes showed that the corrosion ratio increases gradually throughout the network (-0.68 and 8.52) mostly in the autumn and the winter. The results showed that 72% of samples with minor corrosion based on the Langlier index had major corrosion based on the Rizner index. the water network of Kian city has a variable corrosion ratio (minor to major). In order to make a more comprehensive and accurate decision, it is recommended to use Langlier and Rizner indexes together. Application of these methods is very simple in comparison with other methods.