Activated sludge process for simultaneous biological removal of nitrogen and phosphorus

摘要

An activated sludge process for the simultaneous biological removal of nitrogen and phosphorus. The present invention provides (A) a step of supplying the sewage to a treatment tank containing activated sludge to form a mixture of the sewage and the activated sludge, the volatile fatty acid in the mixture An additional volatile fatty acid or a salt thereof is added so that the total amount is equal to or greater than the threshold, (B) a non-aerobic treatment of the mixture in the treatment tank, (C) the treatment tank Aerobic treatment of the mixture that has been non-aerobically treated in step (D) allowing the activated sludge in the mixture to settle and separating the activated sludge and treated water; and (E) the treated water A method of removing phosphorus compounds and nitrogen compounds in sewage, wherein the activated sludge includes at least nitrifying bacteria, denitrifying bacteria, and phosphorus accumulating bacteria. . [Selection figure] None