Anode Modification Of Microbial Fuel Cells Based On Polypyrrole And β-cyclodextri

Microbial fuel cell（MFC）is a green bioelectricity generation device that integrates wastewater biodegradation and electrochemical conversion processes.Since it can generate electricity while biological treatment of wastewater,and the reaction process produces almost no harmful substances that pollute the environment,it is gaining more and more attention in environmental and energy research and application fields.The physical and chemical properties and surface characteristics of the anode material,which is an important carrier for the attachment and electron collection and transfer of the electricity-producing microorganisms,play a key role in the electricity production capacity and water purification effect of microbial fuel cells.Anode materials with good performance should meet the requirements of good electrical conductivity,large specific surface area,high biocompatibility,and high cost performance,which are conducive to the attachment of electricity-generating microorganisms and promote the migration of electrons.Therefore,it has become a common and effective method to improve the performance of microbial fuel cells through anode modification.This thesis explores an effective method of anode modification based on polypyrrole andβ-cyclodextrin with the goal of improving the treatment effect and power production capacity of microbial fuel cell wastewater.The experimental system of microbial fuel cell was established by using molasses wastewater as the anode filler,a mixture of K₃[Fe（CN）₆]and Na Cl as the cathode electrolyte,and carbon felt as the anode substrate material.Specifically,polypyrrole and Fe₃O₄ were electrodeposited on the carbon felt anode by electrochemical deposition,and the optimal deposition time of polypyrrole was determined by controlling the deposition time of polypyrrole on the anode to maximize the specific surface area of the carbon felt anode,so as to develop a new Fe₃O₄-polypyrrole（PPy）composite modified carbon felt anode（Fe₃O₄-PPy/CF）;a simple immersion A new composite modified anode ofβ-CD-PDA/CF was prepared by using a simple submersion method withβ-cyclodextrin（β-CD）and polydopamine（PDA）to modify the carbon felt anode.The results of experimental runs showed that the anode modified by Fe₃O₄-PPy composite could effectively improve the power generation capacity and wastewater treatment efficiency of MFC due to the good electrocatalytic activity of polypyrrole.Especially when the deposition time was 50 min,the modified anode(Fe₃O₄-PPy₅₀/CF)played a more significant effect on improving the MFC performance.Compared with the unmodified carbon felt anode,Fe₃O₄-PPy₅₀/CF led to a 59.5%increase in the steady-state current density of the MFC and a 95.3%increase in the chemical oxygen demand（COD）removal of molasses wastewater.The maximum current density of MFC withβ-CD-PDA/CF composite modified anode was 0.181 m A-m-2,which was 86.6%and 22.3%higher than that with CF andβ-CD-CF,respectively;the COD removal rate of molasses wastewater reached 68.9%,while only 30.7%and 49.8%with CF andβ-CD/CF anodes and49.8%.The results showed that both the Fe₃O₄-Ppy anode modification method and theβ-CD-PDA anode modification method proposed in this thesis were effective in improving the comprehensive performance of microbial fuel cells.The hydrophilicity,surface roughness,specific surface area and electrical activity of the modified electrodes were improved,which enhanced the attachment ability and electron transfer ability of the electricity-producing microorganisms,thus improving the MFC wastewater treatment effect and electricity production capacity.Therefore,both Fe₃O₄-PPy composites andβ-CD-PDA composites are effective electrode modification materials that can be used in the anode modification of microbial fuel cells to improve the microbial fuel cell performance.