ARS | Publication request: Abatement of ammonia emissions from swine lagoons using polymer enhanced solid-liquid separation

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 11, 2007
Publication Date: December 1, 2007
Repository URL: http://hdl.handle.net/10113/12872
Citation: Szogi, A.A., Vanotti, M.B. 2007. Abatement of ammonia emissions from swine lagoons using polymer enhanced solid-liquid separation. Applied Engineering in Agriculture 23(6):837-845.

Interpretive Summary: Numerous studies have shown that widespread use of anaerobic lagoons to treat and store liquid manure from confined swine production in North Carolina can contribute to atmospheric deposition of ammonia and air pollution. An investigation was conducted to determine the effects of separating solids from liquid swine manure on ammonia emissions from lagoons. This determination was done at full-scale in two contiguous swine production operations that had similar animal production management. Both operations had treatment lagoons with similar storage volume and surface area (0.9 hectares). One of these operations was maintained as a control using the traditional anaerobic lagoon treatment method. In the second operation, liquid manure received a solid-liquid separation treatment using a synthetic flocculant prior to lagoon storage. In average, the solid-liquid separation treatment separated 85% of total suspended solids and 81% of organic nitrogen from the liquid entering the lagoon. The ammonia gas emissions from both lagoons were measured simultaneously during a ten-month period using ammonia traps. Ammonia emissions from the traditional anaerobic lagoon (control) totaled 12,542 kilograms of nitrogen per year. This compares to lower ammonia emissions of 3,426 kilograms of nitrogen per year from the anaerobic lagoon with solid-liquid separation. Although water quality changes were modest in the retrofitted lagoon with respect to the control, total annual ammonia gas emissions abatement in the lagoon with solid-liquid separation was 73% with respect to traditional anaerobic lagoon. These results overall demonstrate that solid-liquid separation technologies can substantially reduce ammonia emissions from anaerobic swine lagoons.

Technical Abstract: A study was conducted to determine the effects of solid-liquid separation of liquid swine manure on ammonia emissions from lagoons. This determination was done at full-scale in two contiguous swine production units that had similar animal production management. One of these units was maintained as a control using the traditional anaerobic lagoon treatment method. In the second production unit, liquid manure received an enhanced-polymer solid-liquid separation treatment prior to lagoon storage. The ammonia gas fluxes from both lagoons were measured simultaneously during a ten-month period (Feb.-Nov., 2004) using passive flux samplers. In average, the solid-liquid separation treatment separated 85% of total suspended solids (TSS), 60% of total solids (TS), 73% of chemical oxygen demand (COD), 81% of organic N, and 8% of total ammoniacal N (TAN) from the liquid entering the lagoon. Ammonia emissions from the traditional anaerobic lagoon (control) totaled 12,542 kg N/yr (13,633 kg N/ha/yr). This compares to lower ammonia emissions of 3,426 kg N/yr (or 3,684 kg N/ha/yr) from the anaerobic lagoon with solid-liquid separation. Although water quality changes were modest in the retrofitted lagoon with respect to the control, total annual ammonia emission abatement in the lagoon with solid-liquid separation was 73% with respect to traditional anaerobic lagoon. These results overall demonstrate that solid-liquid separation technologies can substantially reduce ammonia emissions from anaerobic swine lagoons.