Characteristics of Biological Granular Activated Carbon/Membrane Filtration System Performance for Enhancing Drinking Water Quality

A biological granular activated carbon (BAC) bed has been applied to remove micropollutants from surface water used as a source for water supply. Membrane filtration (MF) has also been introduced in water treatment plants to improve drinking water quality by removing bacteria, viruses, microorganisms, as well as particulate and organic matter. This study investigates the effect of BAC biofiltration as a pretreatment before MF processes and evaluates the performance of BAC/MF systems for treating lake water. The applied filtration rates during the experiment were less than 100 m/d for BAC and 0.5 ㎥/㎡·d for MF. Influent concentrations included humic acid <10 mg/L, turbidity <100 NTU, UV₂₅₄ <0.250 cm-1, and dissolved organic carbon (DOC) <9.7 mg/L. Consequently, both the BAC bed and the BAC/MF system achieved over 90% efficiency in removing turbidity and organic matter, as indicated by UV< SUB >254< /SUB > and DOC measurements. This demonstrates that the BAC bed biofiltration was highly effective in reducing foulants. The transmembrane pressure (TMP) during MF increased proportionally with rising humic acid concentrations, ranging from 2 to 10 mg/L. These findings suggest that incorporating a BAC bed prior to membrane filtration is essential for cost-effective lake water treatment, as it not only efficiently reduces geosmin, 2-MIB, and micropollutants but also mitigates membrane fouling by lowering the TMP.