Abstract
The diffuser of a membrane module for use in water purification was studied and the design specifications of a diffusing trough that has diffusion slits on the sides were obtained. A test-fabricated multi-element large-capacity membrane module that incorporates a diffusing trough was run continuously in a pilot plant. The treated water satisfied the water quality standards, the interval for chemical cleaning was two months or more, and the recovery rate was 95% or more, confirming the processing performance. A large-capacity membrane unit that is capable of application in medium-scale purification plants that treat several thousands of cubic meters of water per day was test fabricated with multiple large-capacity membrane modules. Studies of stability in operation under a high-turbidity load of 60-80 degree turbidity confirmed stable operation over a 25 day period with a treated water turbidity of 0.01 or less and a trans membrane pressure differential of 40kPa.
