FIELD: sanitary; environment protection. SUBSTANCE: method involves supplying sewage water into anaerobic reactor mixing sewage water portions discharged from the anaerobic reactor with unprocessed sewage supplying the so obtained mixture for its being treated in the presence of alkaline reagent in the anaerobic reactor. Carbon dioxide is removed from the mixture of the unprocessed sewage and sewage water from the anaerobic reactor by blowing through methane from the anaerobic reactor. The alkaline reagent is introduced into the mixture of the not processed sewage and sewage water from the anaerobic reactor. The proportions of sewage portions discharged from the anaerobic reactor to those not processed is to be calculated from an equation shown in the patent application. EFFECT: enhanced effectiveness in removing oxygen- consuming impurities from sewage. 3 cl, 2 dwg
