Submitted to: Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2019
Publication Date: 3/6/2019
Citation: Riano, B., Mollinuevo-Salces, B., Vanotti, M.B., Garcia-Gonzalez, M.C. 2019. Application of gas-permeable membranes for semi-continuous ammonia recovery from swine manure. Environments. 6(3):32. https://doi.org/10.3390/environments6030032.
DOI: https://doi.org/10.3390/environments6030032

Interpretive Summary: Gas-permeable membrane technology is a new strategy to minimize ammonia losses from manure, reducing pollution and recovering nitrogen (N) in the form of an ammonium salt fertilizer. Among the technologies that focus on the capture and recovery of ammonia emissions from livestock wastes, the gas-permeable membrane technology has been shown as one of the lowest in energy consumption. In addition, it is carried out at low pressure, it does not require pre-treatment of wastewater, and it does not need addition of any alkali reagent. In the past, the gas-permeable technology technology for N capture has been tested mostly using batch configurations. In this research, a new operational configuration using a semi-continuous operation was tested for the first time. It treated swine manure with a total ammonia nitrogen concentration (TAN) of 3451 milligrams (mg) per liter. The system was operated with low aeration rate to raise pH and nitrogen loading rates of about 500 to 700 mg N per liter of reactor per day. Results showed a consistent 90% TAN recovery. These results suggested that the gas-permeable membrane technology operating in a semi-continuous mode has a great potential for TAN recovery from manure.

Technical Abstract: Gas-permeable membrane technology is a new strategy to minimize ammonia losses from manure, reducing pollution and recovering N in the form of an ammonium salt fertilizer. In this work, a new operational configuration to recover N using the gas-permeable membrane technology from swine manure was tested in a semi-continuous mode. It treated swine manure with a total ammonia nitrogen (TAN) concentration of 3451 mg per liter. The system was operated with low aeration rate (to raise pH), and with hydraulic retention times (HRT) of seven days (Period I) and five days (Period II) that provided total ammonia nitrogen loading rate (ALR) treatments of 491 and 696 mg TAN per L of reactor per day, respectively. Results showed a uniform TAN recovery rate of 27 g per square meter of membrane surface per day regardless of the ALR applied and the manure TAN concentration in the reactor. TAN removal reached 79 percent (%) for Period I and 56% for Period II, with 90% of recovery by the membrane in both periods. Water capture in the acidic solution was also uniform during the experimental period. An increase in temperature of 3 degree Celsius of the acidic solution relative to the wastewater reduced 34% the osmotic distillation and water dilution of the product. These results suggested that the gas-permeable membrane technology operating in a semi-continuous mode has a great potential for TAN recovery from manure.