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The United States Department of Agriculture (USDA) and Environmental Protection Agency (EPA) have identified ammonia loading in wastewaters associated with animal farming operations to be a general area of concern. These concerns include ammonia discharge into surface and ground waters, a water quality issue, and corresponding ammonia emission, an air quality issue. This renewed focus at the state and national levels prompt re-evaluation of management practices for animal waste handling and treatment. Current waste management practices include both slurry and flush systems, with lagoon storage and treatment, which may require separation of solid and liquid components after collection, but prior to treatment, or conveyor belt systems which allow for solid-liquid separation at the point-of-generation, and independent treatment procedures.

The large-scale belt housing unit at the North Carolina State Swine Extension Facility allowed for immediate separation, collection and subsequent treatment of the liquid waste component. This study reports the results of the Ammonia Recovery Process (ARP) in extracting ammonia from collected swine urine. Waste was initially treated with urease and the solution pH was adjusted. This pre-treated swine urine then served as the influent for the ARP demonstration.

The ARP unit employed a metal ion treated resin bed, having a wet volume of approximately 10.2 L. Mechanically filtered waste was processed at a flow rate of up to 800 mL/min. During each run the pH of the effluent was monitored as an operational parameter. Ammonia content of collected effluent samples was determined by ion selective electrode. Approximately 300 L of swine urine were processed in three independent run sets, each consisting of several runs, which examined initial ammonia extraction efficiencies and overall column efficiencies as a function of column regeneration protocol.

Subsequently the study routinely achieved greater than 90% reduction in ammonia content for swine urine samples that had initial ammonia concentrations of approximately 6000 mg/L. The study demonstrated that the ARP represents a viable innovative technology when employed to address environmental issues related to ammonia contaminated waste streams.