REDUCTION OF DISSOLVED ORGANIC MATTER IN CONTAMINATED SHALLOW WELL WATER BY FERRIC CHLORIDE COAGULATION WITH CERAMIC MEMBRANE FILTRATION

Abstract

This study presented a reduction of dissolved organic matter in contaminated shallow well water with landfill leachate by coagulation and ceramic microfiltration (CM) membrane. Contaminated shallow well water was collected from an abandon open dump site in Chiang Mai, Thailand. Ferric chloride (FeCl3) was used as a coagulant. CM membrane with nominal pore size 0.1 µm was examined. The results illustrated that the contaminated shallow well water contained dissolved organic carbon (DOC) of 12.6 mg/L and UV254 of 1.545 cm-1. In addition, the contaminated shallow well water was fractionated into hydrophilic (HPI) and hydrophobic (HPO) fractions. DOC for HPI and HPO fractions were 8.1 and 3.0 mg/L, respectively. Optimal dosage and pH were observed at 100 mg/L and 6.5, respectively. As a result, DOC was reduced by 25%. Subsequently, supernatant water after coagulation was filtered through CM membrane. The result showed that DOC in the filtrated water was insignificantly different. For chlorination process, total trihalomethane in contaminated shallow well water was 10.8 µg/L and it was reduced to 6.0 and 4.5 µg/L by coagulation process and coagulation combined with CM membrane, respectively.