Feasibility of Anaerobic Ammonium Oxidation in the Presence of Bicarbonate

Mixed culture enriched for anammox process over 400 days were used in this study to check the feasibility of anaerobic ammonia oxidation in the presence of HCO₃ ⁻. Batch studies proved the feasibility of bio-chemical anaerobic ammonia oxidation in the presence of HCO₃ ⁻ and the ammonia removal obtained was around 36 % within 24 h. The role of bicarbonate as an electron acceptor yet to be proved thermodynamically. The batch kinetic studies showed that the rate of anoxic ammonia oxidation was higher within 2 h and the rate of ammonia oxidation increased as the concentration of ammonia increased. The total nitrogen removal from the system was very effective without having much accumulation of NO₂ ⁻ and NO₃ ⁻. The specific substrate utilization rate of the biomass for ammonia oxidation was 31 mg/g MLVSS/h. From the results of this study, the new process may be employed for the economic removal of ammonia from wastewaters having low to moderate concentrations of ammonia.