Simultaneous antibiotic degradation, nitrogen removal and power generation in a microalgae-bacteria powered biofuel cell designed for aquaculture wastewater treatment and energy recovery

A novel microalgae-bacteria powered biofuel cell (MBBFC) is designed for aquaculture wastewater treatment and energy recovery, in which algal-bacterial cooperation coupling with cathodic bioelectrochemiccal process for efficient nitrogen removal while simultaneously driving anodic bioelectrochemical degradation of antibiotic florfenicol (FLO) with instantaneous electrons uptake from co-substrate. 100 mg/L of ammonia nitrogen is removed completely within 90 h in the algal-bacterial biocathode of MBBFC, mainly attributed to the activity of ammonia oxidizers in the presence of photosynthetic oxygen and the resultant nitrate/nitrite are acceleratively removed by the cathodic bioelectrochemical denitrification. The antibacterial activity of FLO is eliminated through anodic bioelectrochemical enhanced co-metabolic reductive dehalogenation. The feeding 0.5 mg/L of FLO to the anode promotes the growth of Pseudomonas species, which results in a 3.2-fold increase in power output. FLO diffused from the anode to the cathode can exert a selection pressure to the cathodic bacterial community and thereby affecting the nitrogen removal performance of the microalgal-bacterial cathode. The MBBFC shows a great potential for aquaculture wastewater treatment with simultaneously bioelectrical energy recovery. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.