Simultaneous copper removal and electricity production and microbial community in microbial fuel cells with different cathode catalysts

With graphene oxide (GO), platinum carbon (Pt/C), and reduced graphene oxide (rGO) as cathode catalysts, three types of single-chamber microbial fuel cells (MFCs) were constructed for simultaneous Cu²⁺ removal and electricity production. Results indicated rGO-MFC and Pt/C-MFC had much better Cu²⁺-removing and electricity-generating performance than that of GO-MFC, and rGO-MFC presented preferable electrochemical characteristics compared with Pt/C-MFC. Microbial community analysis indicated Geobacter dominated anodic biofilms and was mainly responsible for organics degradation and electricity generation. The dual bio-selective effects by cathode catalyst and toxic Cu²⁺ resulted in different cathodic microbial communities. At high Cu²⁺ contents, Nitratireductor, Ochrobactrum, and Serratia as efficient Cu²⁺-removing genera played key roles in Pt/C-MFC, and Azoarcus predominant in cathodic biofilms of rGO-MFC might be important contributor for the favorable performance in this case.