Treatment of aquaculture wastewater by C-MFCs

Abstract

Chlorella microbial fuel cells (C-MFCs) may be an alternative technology for wastewater treatment. Using microalgae and activated sludge as raw materials, the anode of the MFC was connected in series with a chlorella reactor to establish C-MFCs, so that the simulated aquaculture wastewater was first anaerobically treated in the anode chamber and then aerobically treated in the chlorella reactor. The study found that at a 3:1 N:P ratio and 1000 Ω external resistance, NH3N, COD, and TP removal rates were 69.93 ± 1.84 %, 80.30 ± 3.4 %, and 54.44 ± 4.5 %, respectively, with a maximum chlorophyll content of 0.1049 mg∙m−3. The maximum voltage and maximum power density of 32.94423 mV and 102.37 mW∙m−2. The microbial community structure of the anode chamber was analyzed and the results were as follows: At N:P = 3:1, the dominant bacteria at the genus level in the anode chamber were Klebsiella (47.23 %) and Glucuronobacterium (28.87 %). It can be concluded that N:P affects the power generation capacity of C-MFCs and the removal of NH3N, COD, and TP. The power generation capacity and removal of NH3N, COD, and TP by C-MFCs were best when N:P = 3:1. The regulation of nitrogen and phosphorus in aquaculture wastewater can effectively enhance the performance of C-MFCs.