FAST START-UP MARINE ANAMMOX PROCESS USING INTENSIVE SHRIMP POND SOLID WASTE AS INOCULUM IN FILTER BIOREACTOR

Abstract

Intensive shrimp culture waste contains high nitrogen, which can reduce water quality and environmental-carrying capacity. Anaerobic ammonium oxidation (anammox) is a potential and economical nitrogen removal process. However, limited information is available on the application of anammox process in aquaculture. The purpose of this study was to start up an anammox process in two filter bioreactors (FtBR) based on different inoculums. Run 1 used intensive shrimp solid waste, and Run 2 used intensive shrimp solid waste and granular of fresh anammox bacteria belonging to Candidatus Brocadia fulgida. Ammonium and nitrite concentrations of 70-100 mg N L-1 each were added to filtered and sterilized seawater as synthetic wastewater and flowed to the reactor with HRT 24-hour. After 120 days, the maximum ammonium conversion efficiency (ACE), nitrogen removal efficiency (NRE), and nitrogen removal rate (NRR) for Run 1 and 2 were 82.48%, 72.58%, 0.12 kg N (m3·d)-1 and 83.06%, 63.59%, 0.10 kg N (m3·d)-1, respectively. Experiment nitrogen stoichiometric ratios of NH4+:NO2-:NO3- were 1:1.40:0.12 and 1:1.13:0.14, which were close to the stoichiometry of the anammox process. Fast start-up of anammox process was achieved using intensive shrimp solid waste as inoculum. Anammox can be a new method for developing intensive shrimp culture wastewater treatment.