Abstract

The most important types of the subsidiary compounds which are produced as by-products of disinfection process are trihalomethanes, haloacetic acids, haloacetonitriles, chlorites, chlorinated hydrates, formaldehydes, and cyanogen chlorides. Given the adverse effects of disinfection byproduct compounds in drinking water, especially the carcinogenic effects of trihalomethanes, the aim of this study was to evaluate the effect of heating the water to reduce or eliminate the amount of trihalomethanes in drinking water in the city of Sanandaj. To conduct this study, 12 samples were collected from the three endpoints of the water distribution network in Sanandaj in September 2015 (the sampling was carried out in places where, according to the results of the previous samplings, had the highest amount of trihalomethanes compared to other parts of the water distribution network). Results were analyzed using Excel statistical software. The results showed that after boilling water for 1 minute, chloroform reduced from 27 to 6.8 μg/l (74.8 removal), after 3 minutes it reduced to 4.1 μg/l (84.8 removal), and finally after 5 minutes it reached zero μg/l (100 removal). After boiling water for 1 minute, dichlorobromomethane reduced from 26 to 7 μg/l (73.1 removal), after 3 minutes it reduced to 4.1 μg/l (87.7 removal), and after 5 minutes it reached zero μg/l (100 removal). After boiling water for 1 minute, dibromochloromethane reduced from 8 to 4.2 μg/l (70 removal), and after 3 minutes it reached zero μg/l (100 removal). After boiling water for 1 minute, bromoform reduced from 8 to 0.9 μg/l (55 removal), and after 3 minutes it reached 0 μg/l (100 removal). Given that chloroform and dichloromethane constitute the highest percentage of trihalomethanes in water samples in Sanandaj, boilling the water, which is a very cost effective method without a need for expensive laboratory equipment and materials, can have a significant impact in the removal of these dangerous chemicals.