A PROCESS FOR REDUCING CONCENTRATIONS OF HAIR, TRASH, OR FIBROUS MATERIALS IN A WASTE WATER

摘要

A process for reducing hair, trash or fibrous materials concentration in a waste water treatment system having a membrane filter in conjunction with a bioreactor comprises flowing a portion of mixed liquor through a screen in a side stream. The flow rate of the mixed liquor through the screen is about no more than the average design flow rate of the waste water treatment system. The screenings can be either treated or disposed of directly or in combination with the waste activated sludge. The openings of the screen are between about 0.10 mm and about 1.0 mm in size as can be provided by, for example, a rotary drum screen. The invention can be used to provide both screening and sludge thickening.