AWWA MTC57645

Recently, a number of high rate, high performance clarification processes have come to prominence in drinking water treatment. Among these is the ballasted flocculation process marketed as ACTIFLO(R). This process combines high rate (clarification rates of 25gpm/ft2 and higher) with outstanding effluent quality (typically less than 1 NTU). These characteristics make ACTIFLO(R) an appealing match with membrane filtration, in principle. However, concerns over membrane fouling arising from polymer carryover have slowed the adoption of this process combination. The objective of the work described in this paper was to investigate the suitability of ACTIFLO(R) followed by submerged membrane filtration as a process for pre-engineered water treatment systems. The results of pilot testing this process combination at three surface water treatment sites are described. Includes tables, figures.