Double Chamber Microbial Fuel Cell Anode Preparation And Application In Dye Decolorization

Microbial fuel cells(MFCs)is an emerging green energy technology which effectively degrades organic pollutants while directly converting chemical energy into electricity.Nowadays it helps to alleviate the energy shortage and environmental pollution problems and has far-reaching significance in new energy development and resource utilization.However,there are many limitations on this technology.Among them,the common electrode materials show the low electrical conductivity and electron transfer efficiency for the low specific surface area and poor biocompatibility,which are not friend to growth and attachment of microorganisms.Graphene as a new type of carbon material,is stable and conductive with unique physical,chemical and electrochemical properties,and has broad application prospects.As a typical printing and dyeing wastewater pollutant,the effective green degradation method of azo dyes has been a hot topic.Although with good degradation effect,the existing treatment methods consume more energy and incompletely degradation cause secondary pollution to the environment.Therefore,in this work,green reduced graphene oxide anode electrode was prepared to improve the electricity production and methyl orange dye degradation of MFC simultaneously.Results are as the following:Firstly,according to the shortcomings of common carbon-based anodes,reduced graphene oxide(r GO)anode electrodes were prepared with different natural reducing agents,and operational tests of the power production capacity were performed in a two-chamber MFC reactor.The green tea extract reduced graphene oxide(GT-r GO)anodes showed better power production capacity and biocompatibility.The maximum power density reached 773.9 m W/m2 in the MFC,which was 6.2 times higher than that of the common carbon cloth(CC)electrode,and the maximum output voltage was 30%higher than that of the CC electrode.Secondly,further improving of the electrode biocompatibility carried out was conductived,polydopamine solution and GT-r GO anode was synthesized based on the one-pot method.The water contact angle of polydopamine composite green graphene(GT-r GO-PDA)anode,was reduced to 52.50°.The bioloading and power production capacity of the MFC reactor with(GT-r GO-PDA)anode were further improved.The maximum power density reached 1375.8 m W/m~2,which was 78%higher than that of GT-r GO electrode.Finally,different anodes were compared to further investigate the simultaneous power production and methyl orange dye decolorization ability in MFC.The GT-r GO-PDA anode existed the best dye decolorization ability and simultaneous power production performance than other two electrodes.The MFC with GT-r GO-PDA anode operated at 50 mg/L dye concentration and neutral conditions achieved 98%dye decolorization rate for 24 h compared to the common carbon cloth electrode,and the simultaneous power production voltage increased by 40%.Meanwhile,after 15 days of continuous operation under optimal conditions,the confocal scanning laser microscopy and 16S r DNA sequencing were used to analyze the activity and community of microorganisms that the GT-r GO-PDA electrode was loaded with a higher number of microbial active metabolic increasing of electricity production microbial communities.The modification of the anode by using reduced graphene oxide and PDA significantly enhanced the simultaneous electricity production performance and improved the dye removement of MFC.