Affecting Factors On The Treatment Of Aging Landfill Leachate By Microbial Fuel Cell

In this paper,microbial fuel cells were used to treat the aging landfill leachate for environmental safety.The influence of the reactor type,electrode type,electrode parameters,the type and composition of the electrode liquid,the combination of microbial fuel cells and microbial electrolysis cell on the performance of the microbial fuel cells was systematically studied and analyzed.The regularity and mechanism of power generation and pollutant removal are also discussed.The main achievements are as follows.Using Na AC as the anode carbon source to start the double chamber MFC,the electric performance of the biological cathode MFC is superior to the chemical cathode MFC,and the stable voltage,the open circuit voltage and the maximum power density of the aerobic MFC are all superior to the anaerobic MFC after the start-up.When chemical MFC and aerobic MFC use the 100% landfill leachate to produce electricity,the maximum output voltage,maximum output power density and COD removal ratio of chemical MFC are better than that of aerobic MFC,but the removal rate of ammonia in aerobic MFC is slightly higher than that of chemical MFC.Cathode material is the main factor affecting the power generation performance of MFC,and anode material is the key factor affecting the removal efficiency of pollutants in MFC.The performance of double chamber MFC with carbon cloth as anode and carbon felt as cathode is the best.After cathode loaded Mn O2/r GO,the power generation property and the treatment efficiency of the main pollutants such as COD and NH3-N in the aging landfill leachate of the anode substrate are better than those of the MFC without loading catalyst.When the anode modification of the single chamber MFC by heat treatment,and heat combined with chemical oxidation treatment,the biocompatibility and electron transfer efficiency of the anode can be improved,and the power generation performance of the microbial fuel cell can be improved and the removal rate of ammonia in the aging landfill leachate is improved.In the treatment of different concentration of landfill leachate,the COD removal rate of the anode chamber and the output voltage in the dilution multiple of the anodic leachate are first increased and then decreased,the average maximum output voltage of chemical MFC is higher than that of biological cathode MFC,the coulomb efficiency decreases with the increase of the initial concentration of the leachate.The removal rate of NH3-N in the anode chamber increases with the increase of the leachate ratio and migrates to the cathode partially under the action of the concentration gradient.Different concentrations of aged landfill leachate as substrate of a single chamber air cathode MFC can improve the biodegradability of the substrate leachate of the cell,the maximum output voltage and power density of the MFC with the concentration of 40% is the highest while the internal resistance are the smallest,the removal efficiency of COD in the anode substrate is the best.When the concentration of aged landfill leachate is 100%,the coulomb efficiency and ammonia removal rate of the cell are the highest.A new process for treated aged landfill leachate as cathode fluid is not conducive to improving the electricity production performance of the double chamber MFC,but it can effectively improve the removal rate of COD and ammonia in the treated aging landfill leachate.When the area ratio of anode and cathode for double chamber MFC and single chamber MFC changes,the electricity generation property of MFC betters with the increase of electrode area,and the effect of cathode area change on the power generation property is more obvious than that of the anode area change.The double chamber MFC with anode to cathode area ratio of 2:2 has the best electricity generation performance,while the electricity producing performance of the single chamber MFC with area ratio of 4:2.25 is best.From the perspective of electricity generation performance and pollutant removal efficiency,double chamber MFCs are superior to single cell MFCs in general.When the electrode spacing of single chamber MFC is 2cm,the output voltage is the largest,the power generation cycle is the longest,the maximum power density is the largest,and the COD removal rate is the highest.When the spacing is 4cm,the output voltage is the lowest,the power generation cycle is the shortest and the maximum power density is the minimum.When the external resistance of the microbial fuel cell is changed to the microbial electrolysis cell,the output voltage is greatly increased,the maximum output power density is increased,the internal resistance is obviously reduced,and the degradation rate of COD in the MFC leachate is enhanced.When 2 microbial fuel cells are connected to 1 microbial electrolysis cells,the removal rate of COD is 6 times than that of 1 microbial fuel cell in series with 1 microbial electrolysis cell.And the removal rate of ammonia in the microbial electrolysis cell combined with microbial fuel cells is more than 90%.