Study On Microbial Fuel Cell Treatment Of Oil Wastewater From Ship Engine Room Bilge

In order to solve the problem of difficult removal of emulsified oil from bilge water,a microbial fuel cell（MFC）was used as a reaction generator,focusing on the construction of a mixed exoelectrogenic bacteria group and development of a new type of biomass anode material modified by polypyrrole/graphene oxide（PPy/GO）.Finally,the MFC unit was used to treat oil emulsified from bilgewater.At the same time,response surface methodology（RSM）was used to optimize environmental factors to improve the degradation and electrical performance of MFC.The main research contents and results are as follows:（1）A novel PPy/GO walnut shell-based biochar anode material was prepared by pyrolysis of a walnut shell at 400°C and blending modification of biochar with PPy/GO.The results of FTIR,SEM and XRD showed that PPy/GO had been successfully modified on the surface of biochar.There are abundant oxygen-containing functional groups on the surface of biochar electrode modified by the PPy/GO.The contact angle of 0°that is much lower than that of the graphite felt（GF）electrode with the contact angle of 127.666°,enhances the wettability and hydrophilicity of biochar significantly,and improves the biocompatibility of the electrode material,which are beneficial to the attachment of microorganisms.（2）The maximum output voltage of MFC loaded with modified biochar anode was as high as 530 m V,which was 20.45%and 10.42%higher than that of MFC loaded with GF anode and biochar anode,respectively.The maximum power density was as high as2362.41 m W/m^-2,which was 5.55 and 1.75 times that of MFC loaded with GF anode and walnut shell biochar anode,respectively.The biochar anode modified by the PPy/GO has superior charge transfer kinetics,which significantly improves the electrical performance of MFC.（3）The high-efficiency exoelectrogenic bacteria S6 composed of Saccharomyces cerevisiae、Clostridium butyricom、Wickerhamomyces anomalus、Bacillus subtilis、Rhodopseudomonas palustris was constructed.At the same time,S6 was taken as the research object,and the important factors affecting the degradation rate of bacteria S6were screened through single-factor experiments.The optimal degradation conditions were obtained by mathematical model:when p H was 7.25,inoculation amount was6.44%and salt content was 5.96 g/L,the maximum degradation rate reacheed83.6245%,and the actual experimental value was 83.50%,indicating that the model prediction data were accurate and reliable.GC/MS detection showed that S6 had the best degradation effect on n-alkanes in oil pollution,with an average degradation rate of85.49%in 7 days.Exoelectrogenic bacteria can rapidly decompose oil pollutants into small molecular organic compounds,which provides abundant“nutrients”for microbial metabolism.The biocompatibility and specific surface area of the new anode material modified by PPy/GO were significantly enhanced,and the conductive layer formed could significantly improve the electrochemical activity and electron transfer rate of the biofilm.The synergistic effect of PPy and GO could significantly improve the degradation efficiency and electrical performance of MFC f,providing theoretical support for the further development of oil-containing wastewater treatment technology.