Title: Streamlined ammonia removal from wastewater using biological deammonification process Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 8, 2012
Publication Date: July 8, 2012
Citation: Vanotti, M.B., Martinez, J., Magri, A., Szogi, A.A., Fujii, T. 2012. Streamlined ammonia removal from wastewater using biological deammonification process. In: Proceedings of the International Conference of Agricultural Engineering CIGR-Ageng, July 8-12, 2012, Valencia, Spain. Technical Abstract: In this work we evaluated biological deammonification process to more economically remove ammonia from livestock wastewater. The process combines partial nitritation (PN) and anammox. The anammox is a biologically mediated reaction that oxidizes ammonia (NH4+) and releases di-nitrogen gas (N2) under anaerobic conditions using nitrite (NO2-) as the electron acceptor. We present research done using two deammonification configurations: a two-stage process (PN in one tank and anammox in another), and a one-stage deammonification process (PN and anammox in a single tank). In both cases, a high performance nitrifying sludge (HPNS) (ARS Culture Collection, NRRL B-50293) was used for PN and Brocadia caroliniensis (NRRL B-50286) was used for the anammox reaction. The two-tank process was carried out using sequencing batch reactors (SBR), one aerated and the other anaerobic, at 32 degrees Celsius. The single-tank process was carried out in an aerated vessel operated under continuous flow. It contained biofilm plastic carriers at 30% volume per volume packing ratio that were fluidized by the aeration. The process water temperature was 22 degrees Celsius and dissolved oxygen generally below 0.5 milligrams per liter. In the PN-SBR reactor, the nitrite production rate obtained at was 0.91 grams (g) nitrite-nitrogen per liter reactor of per day. The PN effluent contained 1.38 g nitrite-nitrate per gram ammonium-N, which was within 5% of the target oxidation of ammonium to nitrite of 57%, which corresponds with the reaction ratio of anammox. In the second SBR, the anammox process was effectively applied to the PN effluent, attaining a nitrogen conversion rate of 0.36 grams nitrogen per liter of reactor per day (14.3 milligram nitrogen per gram of volatile suspended solids per hour) and anammox stoichiometric ratios of 1.00:1.32:0.15. For the single-tank deammonification, total N removal rates of 0.75 to 1.0 grams of nitrogen per liter of reactor per day were obtained for both synthetic and swine wastewater. The stoichiometry of the reaction obtained in the single-tank process was consistent with deammonification process theory combining partial nitritation and anammox: ammonium + 0.88 oxygen -->0.44 dinitrogen + 0.11 nitrate + 1.43 water + 1.14 hygrogen ion (H+). Compared to conventional nitrification/denitrification, a partial nitritation/anammox pathway (deammonification process) can reduce 58% of the oxygen requirement to biologically eliminate the ammonia from wastewater. Thus, it offers the potential to reduce the cost of treatment of ammonia in livestock wastewaters containing high ammonia nitrogen.