Device and method for enhancing nitrogen and phosphorus removal based on multistage ao partial denitrification coupled with anammox in combination with sludge hydrolytic acidification

Abstract

A device and method for enhancing nitrogen and phosphorus removal based on a multistage AO partial denitrification coupled with Anammox process in combination with a sludge hydrolytic acidification mixture belong to the technical field of active sludge method wastewater treatment. A system includes a water tank, a water pump, a biochemical reaction zone, a hydrolytic acidification tank and other devices. A multistage AO step-feed pipeline is used to inject raw water into the reaction zone in a segmented manner, guaranteeing efficient utilization of organic matter in the raw water; biofilm carriers are added into an anaerobic zone and anoxic zones to enrich anammox bacteria, and nitrite nitrogen produced by partial denitrification provides a substrate for the anammox bacteria to realize autotrophic nitrogen removal; a nitrification and phosphorus accumulating bacteria aerobic phosphorus uptake are performed in aerobic zones; and part of excess sludge in a secondary sedimentation tank enters the hydrolytic acidification tank to convert macromolecular organic matter into low molecular weight organic matter, a hydrolytic acidification mixture and the excess sludge in the secondary sedimentation tank synchronously flow back to the anaerobic zone, and as a high-quality carbon source, the low molecular weight organic matter can promote partial denitrification. The system provides a novel method for efficient and energy-saving treatment of municipal wastewater.