Trihalomethane formation potential in drinking water from Minab Steghlal dam to water distribution network in Bandar Abbas, Iran

Introduction: Organic matters enter to drinking water from a variety of sources, but one of the major sources of these compounds in aqueous solution can be decomposed plant and microbial residues. Chlorination is the most common method for water disinfection, the free chlorine in the water reacts with natural organic compounds and form disinfection byproducts. One of the dangerous byproducts is Trihalomethanes (THMs). These compounds are suspected to be carcinogenic for humans. Methods: In this study, 96 samples were taken from 4 points (Mianb Steghlal dam, output Minab water treatment plant, input and output of water treatment plant in Bandar Abbas) within 6 months. Parameters such as TOC, pH, temperature and chlorine residual were measured and used for prediction of THM formation by a methematical model. Results: Results showed that Bandar Abbas drinking water has high TOC and THM formation potential is high. Minimum and maximum of THM was measured 14.78 and 84.86µg/l, respectively. Positive correlation was seen between concentrations of organic carbon and pH with THM formation. Conclusion: Increasing pH and TOC concentration in water, leads to increase of THM formation potential. Bandar Abbas drinking water has high potential to form THM, therefore, it is necessary to consider measures in this field.