Trihalomethane evaluation in chlorinated treated drinking water sources in Saudi Arabia (Aseer region a case study)

This study was conducted to assess trihalomethane levels in Aseer region's main chlorinated treated drinking water sources over four consecutive seasons (Summer, Autumn, Winter, and Spring) and to gain a better understanding of trihalomethane occurrence, amounts, and the factors involved in trihalomethane formation in study area particularly. The study covered thirteen varied drinking water sources including five conventional filtration treatment plants for surface water and two non-conventional treatment plants for groundwater in addition to six desalinated and blended drinking water reservoirs. Results of the study indicated that exceeded the permissible concentration of total trihalomethane at conventional filtration treatment plants of surface water with maximum values ranging from 111.16 ppb to 208.76 ppb with dominant brominated trihalomethane as bromoform (CHBl3) and dibromochloromethane (CHClBr2), especially during the summer season. Results also showed a positive correlation between trihalomethane formation and the level presence of some trihalomethane precursors like organic carbon, turbidity, bromide ion, and free chlorine whereas, a correlation was negative with pH values. (c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

This study assessed the levels of trihalomethane in the main chlorinated treated drinking water sources in the Aseer region over four seasons. The results showed that the concentration of total trihalomethane exceeded the permissible limit in conventional filtration treatment plants, especially during the summer season. The study also found a positive correlation between trihalomethane formation and the presence of certain precursors, such as organic carbon, turbidity, bromide ion, and free chlorine, while pH values had a negative correlation.