The Changing of Dissolved Organic Matter Based on Its Molecular Weight Through Alum Coagulation and Adsorption Activated Carbon

Abstract

Surface water may contain dissolved organic matter (DOM), which is derived from microbial activities in water and discharged from the watershed. Source water is mainly used as raw water for clean and drinking water, and DOM in water could affect the treated water quality. Therefore, it is necessary to remove DOM in water. This study aims to know the efficiency of removal of DOM by using alum coagulation followed by adsorption with activated carbon. In addition, this study applied the chromatograms method to identify the changing of DOM based on its molecular weight. The results show that raw water was composed of two main organic fractions: humic substances and low molecular weight acids and neutral.The humic substances organic fractions have been removed through alum coagulation up to 48%, and removal increased up to 85% through adsorption with activated carbon. The low molecular weight acids and neutral organic compounds have been removed about 85% and 40% in alum coagulation and adsorption,respectively.