Method for removing nitrogen and phosphorous in wastewater

Abstract

The present invention provides to a method for removing nitrogen and phosphorous in wastewater simultaneously from wastewater by employing fermentation broth obtained by anaerobic fermentation of organic solid wastes. The method for removing nitrogen and phosphorous in wastewater of the invention comprises the steps of subjecting organic waste material to anaerobic fermentation at 30 to 40° C. for 2 to 4 days by using anaerobic sludge to obtain fermentation broth; and, adding the fermentation broth to a sequencing batch reactor with alternating anaerobic-aerobic-anoxic cycles under anaerobic and anoxic conditions in a separate manner. In accordance with the present invention, nitrogen in the influent wastewater can be removed more than 95% in total and phosphorous concentration can be kept below 1 ppm regardless of the concentration of organic materials in the influent wastewater. Further, the present method requires no extra pretreatment steps or chemicals which are essential to remove residual ammonia nitrogen in the prior art systems, and lowers the overall cost for wastewater treatment due to the usage of organic waste materials.