High-Efficiency Degradation of Formaldehyde and Bioelectricity Generation by Microbial Fuel Cell

Formaldehyde is a common organic pollutant in water with teratogenic and carcinogenic effects. This study reports that 200 mg l −1 formaldehyde in water can be effectively degraded with generating electricity by using microbial fuel cell (MFC) technology. A novel composite anode M-Co 3 O 4 -PEDOT-GF was prepared by modifying Co 3 O 4 nanoparticles (M-Co 3 O 4 ) derived from ZIF-67 and poly (3,4-ethylenedioxythiophene) (PEDOT) on the surface of Graphite felt (GF). The results showed that the MFC loading M-Co 3 O 4 -PEDOT-GF anode exhibited excellent electricity generation performance and formaldehyde degradation. The maximum voltage of the MFC was 549 mV, 46.0% increase than that of GF anode (376 mV), and higher than N-Co 3 O 4 -PEDOT-GF anode (488 mV) modified with commercial Co 3 O 4 (N-Co 3 O 4 ). The maximum power density of the MFC loading composite anode was 4177 mW m −2 , while that of MFC loading bare GF anode was 1562 mW m −2 . The dominant microorganisms were Pseudomonadales and Rhizobiales at the order level. The removal efficiency of formaldehyde by MFC loading M-Co 3 O 4 -PEDOT-GF anode was 89.2% in 152 h. The high efficiency of formaldehyde degradation was still maintained after 10 cycles. The results could be attributed to the composite anode with loose porous three-dimensional structure and good biological compatibility of PEDOT.