Nutrient Recovery Membrane Technology: Best Applications and Role in Conservation

Abstract. Nitrogen volatilization from animal manure storage and treatment represents a major loss of value as well as a major source of environmental degradation, especially in swine lagoon and sprayfield systems of the Southeast U.S. The most common utilization technology is land application to forage crops but this disposes of nitrogen rather than truly recovers value from the source manure. An evaluation of a pilot-scale system using a hydrophobic, gas permeable membrane to recover ammonia from swine wastewater in a solution of sulfuric acid as first described in the U.S. Patent held by USDA and Vanotti, Szogi, and Hunt was conducted. Results show that recovery depends on the abundance of ammonia nitrogen in the feedstock and worked best with treated wastewater. Based on the results of the evaluation, an optimized membrane reactor could be a viable tool in ammonia nitrogen recovery from a manure treatment system if used in conjunction with digestion.