AWWA MTC64539

Submerged microfiltration (SMF) has proven to be effective for the removal of particles and microorganisms under low operation pressures. However, a major challenge to further application of SMF processes in water treatment plants is to solve the problems of high energy consumption caused by continuous or periodic aeration and flux decline due to membrane fouling. The objective of this research was to develop a technique to minimize energy consumption in SMF system by adjusting aeration rate and filtration mode and to implement this in a pilot scale. A pilot scale submerged filtration unit (50 m³/day), employing hollow fiber modules, was operated to examine the microfiltration efficiency under various operation conditions. Filtration modes such as continuous filtration and batch filtration were compared at various aeration rates. Experimental results indicate that membrane permeability and total hydraulic resistance were sensitive to the aeration rate. The aeration rate should be optimized to generate enough shear and keep the chemical flocs unchanged. Operation with intermittent or even no aeration was possible for feed water with low turbidity (< 5 NTU) and effective to save energy. Includes 6 references, table, figures.