Process for tertiary treatment of waste waters from anaerobic digestion treatment process

摘要

A process for the tertiary treatment of biochemical waste waters comprising the following 4 main steps; (1) adding milk of lime to waste water from the anaerobic digestion treatment process to render the waste water alkaline and recovering NH.sub.3 by reduced pressure distillation, (2) contacting recovered NH.sub.3 with a weakly acidic ion exchange resin to make NH.sub.3 adsorbed in the ion exchanger resin, (3) adding acid to the adsorbed ammonia to form an ammonia salt, and (4) blowing CO.sub.2 into the treated water from which NH.sub.3 has been removed, to thereby recover P, and subjecting the treated water from which N and P have been removed to the activated sludge treatment to remove BOD.