Removal of Dissolved Organic Matter and Disinfection By-products Formation Potential in the Upper Layer during Soil Aquifer Treatment

Abstract

Objectives of this study are to comprehend the removal characteristics of dissolved organic matter (DOM) and disinfection by-products formation potential (DBPsFP) in the upper layer, which has active microbial activities, of soil aquifer treatment for wastewater reuse. Three columns, in which sand was packed with the height of 5, 10 and 30 cm, respectively, were set, and wastewater effluent was continuously discharged. Dissolved organic carbon (DOC) and DBPsFP were measured in the influent and effluent from the columns. 22.4% of DOC was removed only at the 5 cm thick layer from the surface, and the removal efficiency increased to 40.1% by the 30 cm infiltration. Therefore, it was cleared that DOM was actively removed by the upper layer infiltration, and most DOM removal was attributed to biodegradation. It was found that the removal characteristics of each DBPs precursor by biodegradation in the upper layer were different. Chloroform FP and dibromochloromethane FP were also reduced by biodegradation in the 30 cm infiltration (removal ratio was 34.4 and 29.2%, respectively); meanwhile, bromodichloromethane FP did not decrease.