Patent ID: 7534353
Filing Date: 2009-05-19
Classification: B01D,C02F,Y02W,Y10S

Abstract:
1. A process for withdrawing filtered permeate from activated sludge at ambient pressure comprising the steps of: providing a tank; providing an assembly in the tank, the assembly having, feeding activated sludge into the tank to immerse the membranes in the activated sludge at ambient pressure; applying a suction to lumens of the membranes via the permeate port to withdraw permeate at an essentially constant flux from the activated sludge at ambient pressure in the tank; blowing air into the activated sludge at ambient pressure to provide bubbles in the activated sludge at ambient pressure in the tank which bubbles contact the membranes as the bubbles rise through the activated sludge at ambient pressure; and, withdrawing retentate sludge from the tank wherein the steps of blowing air and withdrawing the retentate sludge occur during the step of applying the suction.