Continuous Flow of Microbial Fuel Cells for Metal Wastewater Treatment and Energy Recovery

WANG Luning; SUN Caiyu; WANG Jiayu; LI Yongfeng

doi:10.3969/j.issn.1003-6504.2017.05.018

Abstract：With continuous flow dual-chamber microbial fuel cell as the study object,continuous flow microbial fuel cell for sewage treatment,power generation and the effect of treatment and recovery of metal ions (Cu2+,Ni2+,Cr6+,Cd2+electroplating wastewater,500 mg/L)was investigated,in comparison with the traditional single-chamber microbial fuel cell.Under anaerobic microbial environment itself as a catalyst,artificial dubbed molasses wastewater was used as anolyte,and different toxic liquid metal ion solution as a cathode.The results showed that at the same outer resistance (1 000 Ω),Cr6+electroplating wastewater as the cathode has the best production of electrical properties,with the maximum voltage 114.2mV,power density 35.648 8 mW/m2,Coulomb efficiency 44.13％,and the highest metal ion removal 66％.In contrast Cu2+cathode group is less effective in producing electricity,with voltage stability less than 0.01 V,power density 6.059 mW/m2and Coulombic efficiency 3.78％.In the anode,the simulated molasses wastewater degradation were obtained,with Cd2+cathode group as the most effective treatment,and COD removal rate up to 78％.X-ray diffraction analysis of the MFC cathode reduction product indicated that Cu2+ reduction products included Cu2O and copper,Cr6+ was reduced to Cr2O3,Cd2+and Ni2+ were mainly generated elemental.In this experiment,X-ray diffraction was used to analyze the reducing substances of the cathode electrode,the results were obtained by computer search and compared with international standard PDF.In the four different liquid cathodes,Cu2+ was reduced to form Cu2O crystal and elemental copper.Ni2+ was reduced to form elemental Ni.Cr2O3 and elemental cadmium crystal diffraction peaks respectively appeared in Cr6+ and Cd2+ cathode solution group.