Enhancing recovery of ammonia from swine manure anaerobic digester effluent using gas-permeable membrane technology

• Published in: Waste management (Elmsford) Vol. 49; pp. 372 - 377
• Main Authors: Dube, P.J., Vanotti, M.B., Szogi, A.A., García-González, M.C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01-03-2016
• Subjects: Aeration; Ammonia - analysis; Ammonia recovery; Ammonium Compounds - analysis; Anaerobic digestion; Anaerobiosis; Animal Husbandry; Animals; Bioreactors; Gas-permeable membranes; Hydrogen-Ion Concentration; Manure; Manure - analysis; Membranes; Membranes, Artificial; Nitrification; North Carolina; Nutrient recovery; Recovery; Swine; Swine manure; Technology utilization; Waste management; Waste Management - instrumentation; Waste Management - methods; Waste management; Ammonia recovery; Swine manure; Gas-permeable membranes; Nutrient recovery; Anaerobic digestion
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2015.12.011

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•Low-rate aeration enhanced ammonia recovery of the gas-permeable membrane process.•More than 96–98% of ammonia was recovered from digested swine effluent.•The low-rate aeration reacted with the natural carbonates and increased pH.•Recovery was 5 times faster compared without aeration.•Utilizing aeration resulted in a 70% reduction in costs for the system.
Gas-permeable membrane technology is useful to recover ammonia from manure. In this study, the technology was enhanced using aeration instead of alkali chemicals to increase pH and the ammonium (NH4+) recovery rate. Digested effluents from covered anaerobic swine lagoons containing 1465–2097mgNH4+–NL−1 were treated using submerged membranes (0.13cm2cm−3), low-rate aeration (120mL airL-manure−1min−1) and nitrification inhibitor (22mgL−1) to prevent nitrification. The experiment included a control without aeration. The pH of the manure with aeration rose from 8.6 to 9.2 while the manure without aeration decreased from 8.6 to 8.1. With aeration, 97–99% of the NH4+ was removed in about 5days of operation with 96–98% recovery efficiency. In contrast, without aeration it took 25days to treat the NH4+. Therefore, the recovery of NH4+ was five times faster with the low-rate aeration treatment. This enhancement could reduce costs by 70%.