ENHANCED SEWAGE BIOLOGICAL NITROGEN AND PHOSPHORUS REMOVAL METHOD BASED ON POLYHYDROXYALKANOATES METABOLIC REGULATION

The invention belongs to the technical field of environmental protection, and relates to a method for enhanced biological removal of phosphorus and nitrogen from sewage on the basis of metabolic regulation of polyhydroxyalkanoate, comprising the following steps: leading particulate organic substances obtained by primary sedimentation of sewage and excess sludge discharged from a secondary sedimentation tank into a sludge thickening tank for condensation; placing the condensed organic wastes into a polyhydroxyalkanoate precursor production reactor to synthesize polyhydroxyalkanoate precursors through anaerobic fermentation; after removing nitrogen and phosphorus, pumping the liquid into a polyhydroxyalkanoate precursor reservoir; pumping the polyhydroxyalkanoate precursors into a polyhydroxyalkanoate production reactor to produce polyhydroxyalkanoate; pumping into a conventional bioreactor for removal of phosphorus and nitrogen from sewage to conduct a process for biological removal of phosphorus and nitrogen from sewage. The present invention raises the removal rate of nitrogen and phosphorus up to around 80% to 95%, and the treated effluent water attains to the requirement of the Grade 1A discharge standard for sewage treatment plants. The method has the advantages of easy-to-control processes, low greenhouse gas emissions and reduced sludge production, and low cost of technical renovation and the like.