Development of an anaerobic ammonium oxidation (ANAMMOX) process reactor for aquaculture wastewater treatment

ABSTRACT Treatment of wastewater from aquaculture with high nitrogen compound concentrations would contribute to the sustainable aquaculture industry. The anaerobic ammonium oxidation (ANAMMOX) mechanism was a potential technology considering its capability to directly convert ammonium and produce nitrogen gas under anaerobic conditions. This research aimed to cultivate locally isolated ANAMMOX bacteria from marine samples while exploring the effectiveness of nitrogen removal biologically in a developed fixed film bioreactor. The laboratory-scale experiment used a sludge sample from a local anaerobic lagoon as inoculum. The nitrogen removal efficiency and the development of ANAMMOX bacteria indicate the ANAMMOX process's effectiveness. After 200 days of reactor operation, the ammonium removal efficiency (ACE) was 70.39 and 82.49% of nitrogen removal efficiency (NRE). The nitrogen loading rate (NLR) value was 0.30 kg-N/m3.d and the highest nitrogen removal rate (NRR) was 0.125 kg-N/m3.d. The ratio of stoichiometric for this study was 1 mol ammonium to 1.00 mol nitrite removal to the 0.21 nitrate production (1:1.00:0.21). The findings from this study could establish the implementation of the ANAMMOX technology on nitrogen removal biologically for the remediation of aquaculture wastewater toward an industrial scale.