AWWA MTC69739

Although microfiltration (MF) and ultrafiltration (UF) processes are effective for removing pathogenic microorganisms such as Giardia and Cryptosporidium, they are relatively ineffective for controling organic pollutants and taste and odor materials (TOM). Thus, post-treatment processes were adopted to gain control of these pollutants, including granular activated carbon (GAC), biological activated carbon (BAC = Ozone + GAC), or nanofiltration (NF). In this study, the effectiveness of post-treatment MF process was examined in pilot scale tests. Various system configurations were analyzed, including MF-GAC, MF-BAC, and MF-NF, in terms of removal efficiency and operation cost. Moreover, the post-treatments for MF were compared with those for conventional water treatment (rapid sand filtration: RSF) to verify the assumption that there is an additional advantage for combining MF and GAC/BAC. The work was done at pilot scale using a 50 m³/day plant with submerged microfilters (Cleanfil-S20, Kolon, Korea) and a 15 m³/day plant with a conventional water treatment system. Five process combinations ran in parallel, including MF-GAC, MF-BAC, MF-NF, RSF-GAC, and RSF-BAC. Each process had the treatment capacity of 7.5 m³/day, except for MF-NF having the capacity of 7~10 m³/day. Raw water collected from the Han River was used as feed water and poly-aluminum chloride was used as coagulants. Samples were taken to monitor the qualities of treated water. TOMs such as 2-MIB and geosmin was spiked into the raw water in some cases to further investigate the efficiency of these processes. Includes 3 references, table, figures.