Removal of humic substances with vibratory shear enhanced processing membrane filtration

A drinking water and/or industrial water in Hokkaido island locates in northern Japan, are produced with conventional water production technology from natural river water which contains organic component such as humic substances. A system was designed to remove small particles and/or colored natural organic matters contained in the river water with ultrafiltration membranes. The clean water is supplied to precision product manufacturing process for computer components. Water treated with a conventional water production system such as sand filters still shows color especially in the summer when turbidity and color become high, making it difficult to use the water in the plant. Also a conventiona- l membrane separation system is not suitable to treat the river water coagulated by the poly aluminum chloride (PAC) because of a risk of plugging in the flow path and fouling on the surface of the membrane. In order to solve the problems mentioned above, vibratory shear enhanced processing is used. The system has a unique vibration mechanism much generates shear rates on the surface of the membrane so that it is resistant to fouling caused by PAC in the water. The commercial water production facility achieves fairly high permeate flux compared with conventional membrane separation technology, and has been able to produce the required water quality.