Characteristics of Trihalomethanes (THM) Formation for Groundwater in the Northeasthern Area of Cheju Island

제주도 북동부지역 지하수의 Trihalomethanes (THM) 생성 특성

This study was carried out to investigate the characteristics of trihalomethane (THM) formation from chlorination of groundwater in the northeastern area of Cheju Island. Effects of total organic carbon (TOC) and bromide in groundwater on the THM formation were studied. Samples were taken from two regions withe altitude. The concentrations of TOC and bromide in groundwater were higher at the regions of lower altitude, especially at the altitude below 50m. Generally the THM formation in GA region containing a high TOC was higher than that in GB region containing a relatively high bromide. At the altitude below 100m, the formation of total and brominated THM was highest at GB region. The most part of THM formation was brominated THM at GB region. The formation ratio of chloroform and brominated THM was similar to the others. Among the brominated THM, dibromochloromethane and bromoform in GB region were containing high bromide. Bromodichloromethane and dibromochloromethane in GA region were containing low bromide. At the altitude above 200m, chloroform was formed mainly. Comparing the ratio of brominated THM of total THM in Cheju Island with that in other areas, Seoul and Pusan, it can be konwn that the former showing 51.3% was much higher than the latter showing 6.7% and 28.8%, respectively.