Patent ID: 6709593
Filing Date: 2004-03-23
Classification: C02F,Y10S

Abstract:
Method for treating waste water, comprising:providing first and second inlet streams of waste water of different origins, the waste water of said second inlet stream having a concentration of dissolved impurities substantially higher than that of the waste water of said first inlet stream; in an anaerobic treatment zone subjecting the waste water of said second inlet stream to an anaerobic degradation of the dissolved contents to form digested sludge and digested gas; in an aerobic treatment zone subjecting the waste water of said first inlet stream to an aerobic treatment to form an additional sludge; sending the additional sludge to the anaerobic treatment zone; mechanically dewatering the additional sludge before sending it into the anaerobic treatment zone; and controlling the degree of dewatering in such a way that the concentration of dry substance in the anaerobic treatment zone does not fall below a predetermined minimum value for long periods of time.