抄録
Membrane separation was applied to wastewater treatment in an activated sludge process directly submerging hollow fiber membrane modules in an aeration tank. Advantages of the process are ; 1) no suspended solids in treated water, 2) low energy requirement, and 3) compactness in the total system. The objective of this study in to develop optimum form of the membrane module and the operation cycle for the direct-submerging membrane separation activated sludge process. Five different types of end-free hollow fiber modules were prepared and the effect of intermittent operation cycle was investigated. New indexes for the evaluation of membrane modules were proposed.
The conclusions of this research are as follows :
1) One-end free hollow fiber membrane modules were quite effective for the direct-submerging membrane separation activated sludge.
2) The characteristic of filtration was influenced by length and thickness of hollow fiber.
3) Long and thick fiber membrane module maintained high flux of filtration, while thin this fiber membrane module showed low flux volume, which was caused by the intertwinement of the fibers.
4) According to evaluation indexes (Permeate flow rate efficiency coefficient and particle volume removal time), short intermittent operation cycle (1min-1min) and long cycle (6hours -6hours) showed almost similar characteristics of filtration.
