ABSTRACT
Natural organic matter in drinking water had been considered primarily as a nuisance that mainly interfered with the aesthetic quality of water. Naturally occurring aquatic humic substances are known to be the precursor for the formation of suspected carcinogenic halogen-substituted compounds, trihalomethanes (THMs), when they are disinfected with free chlorine. Various treatment techniques to control THM precursor concentrations in finished water have been reviewed, such as clarification, aeration, chemical oxidation, activated carbon adsorption, ion exchange, and biological degradation. Natural organic carbon consisting of various molecular weight constituents can be fractionated by many available fractionation methods. According to Steelink, the bulk of the organic matter in surface waters comes from the leaching of humic substances from soil organic matter that appears to be derived from living and decaying vegetation in soils.
