Method for treating organic wastewater and organic wastewater treating system

Abstract

A method for treating organic wastewater includes: proceeding with anaerobic fermentation on organic wastewater to obtain a fermentation liquid; nitrifying a portion of the fermentation liquid to obtain a first fermentation liquid containing nitrate nitrogen, and separating the remaining portion of the fermentation liquid to obtain a second fermentation liquid containing propionic acid; mixing the first and second fermentation liquids to obtain a mixture; and removing nitrogen and phosphorus from the mixture and then proceeding with sedimentation to obtain a sediment and a supernatant discharged as purified water. An organic wastewater treating system includes an anaerobic fermentation reactor, an aeration tank, a fermentation liquid separating equipment, a biological removal reactor for removing nitrogen and phosphorus, and a sedimentation tank. The mixing ratio of two fermentation liquids is controlled to achieve balance between carbon, nitrogen, and phosphorus during the nitrogen and phosphorus removal process, achieving highly efficient and simultaneous removal of carbon, nitrogen, and phosphorus without additional carbon source.