The Study On Microbial Fuel Cell Performance With Materials Of Nano-ferroferric Oxide Loads Humic Acid Doped Anode

Humic acid(HA)as electron medium plays an important role in accelerating electron transfer of natural biogeochemical transformation.Exploration of the potential application of humic acid on accelerating electron transfer would provide new ideas for the development of microbial fuel cell(MFC)technology.Herein,the electron transfer availability of humic acid was evaluated by the dual chamber MFC device.And super capacitive material of nano-ferroferric oxide was used to load humic acid to form a stable wrappage(HA@Fe₃O₄)as the doped materials needed for the experimental X-72C/SSM anode.And the effect of doped anode on the electrical performance and stability of the constructed MFC was investigated.This research provides a basis for the application of humic acid on development of MFC technology due to its electron shuttling ability.The results showed as the following:(1)The results proved that electron transfer ability of humic acid could greatly improve electron transfer efficiency between anode and microbes indeed.Among them,the maximum power density of MFC with anode doped with 6.67%of HA was increased by 107%compared with that of the control group.Moreover,the optimal ratio(6.67%)of HA@Fe₃O₄ doped anode group further improved the maximum power generation density to 1487.06 m W m^-2,which increased by 154%compared with the control group.(2)Compared with the control group,both the HA or HA@Fe₃O₄ doped anode group greatly reduced the activation loss energy of the electrode reaction and improved the stability of the doped anode;In addition,the doped anode groups had lower charge transfer impedance than the control group,which improved the electron release efficiency of the electroactive bacterial and enhanced the level of its catalytic degradation substrate.(3)Cyclic voltammetry test showed that HA or HA@Fe₃O₄ doped anode were established a good electronic transfer pathway with Cytochrome c.However,the interaction between HA@Fe₃O₄ and microorganisms was stronger for the corresponding cyclic voltammetry curves showed a larger oxidation peak current,indicating that the addition of nano-ferroferric oxide further accelerated the rate of HA-mediated electron transfer to the anode.(4)Biodiversity research showed that anode doping or not there was a biggish difference on the enrichment of microbial species on it's surface,HA or HA@Fe₃O₄doped anode did influence the composition of microbial species on it's surface,but the detected microbial diversity on the latter doping anode surface was more abundant,on which anode surface observed a significantly higher biofilm density.