Treatment Of Oil Wastewater And Electricity Generation By Integrating Constructed Wetland With Microbial Fuel Cell

Oil contained wastewater contains a lot of petroleum complicated composition organic matter,high concentration of salt ions and some other impurities.The COD and salinity of oil contained wastewater is very high.To sum up,oil contained wastewater that can not get effective treatment will be a serious threat to the environment.The traditional oil wastewater treatment technology can get good treatment effect,but a large amount of energy will be consumed during the process.Oil contained wastewater was treated by the innovative reactor(CW-MFC)that combines microbial fuel cell with constructed wetland.Compared with traditional oil wastewater treatment technology,the CW-MFC not only can achieve satisfactory removal efficiency but also can realize energy recovery.The microbial fuel cell reactor(MFC)alone,innovative reactor(CW-MFC)and a constructed wetland reactor(CW)alone were applied to oil wastewater degradation.Carbon fiber brush after heat treatment was used as the anode mater.The carbon felt that were modified by manganese dioxide(MnO2)serves as the cathode material.The innovative reactor(CWMFC)removal of chemical oxygen demand(COD),total organic carbon,and total nitrogen were compared with other reactor.The voltage of CW-MFC,CW and MFC reactors were measured continuously.The higher power density and output voltage were generated by the CW-MFC with a MnO2 modified cathode.The highest power density of CW-MFC was 102 mW/m2.The highest power density of MFC was 80 mW/m2.Maximum output voltage of CW-MFC were 642 mV.Maximum output voltage of MFC 245 mV.Compared with MFC,the plants play a critical role in cathode potential of CW-MFC.The reactor performance of electricity generation was relate to plants and cathode modification.The chemical oxygen demand removals of CW-MFC,CW,and MFC were between 73% and 75%.The oil removals of CW-MFC,CW,and MFC were over 95.7%.The total organic carbon removals of CW-MFC,CW,and MFC were between 41% and 53%.Organic matters in the oil contained wastewater and effluent of CW-MFC were analyzed by GC-MS.Both the type and concentration of the organic matters in the CW-MFC system effluent were significantly decreased compared with the CW-MFC system influent.Blank activated carbon packing,the CW packing,and the CW-MFC packing of the specific surface area were analyzed by automatic physical adsorption instrument(BET).Specific surface area: blank activated carbon packing > the CW-MFC system packing > the CW system packing.The pore size distribution of the CW-MFC packing and the CW packing pore has a huge difference.The pore volume of the CW-MFC packing and the CW packing pore also has a huge difference.These results indicate that the packing pollution of the CW-MFC system lighter than the CW system.So,the existence of the current inhibited the pollution of on packing materials.