| With the continuous development of industry, electroplating, metallurgy, petroleum industry, pesticide manufacturers and other industries produce large amounts of wastewater containing copper, which has a disastrous effect on the environment and wastes a lot of copper resources. Electrochemical method is especially effective and convenient for copper removal and recovery without secondary pollution. Electrolytic process energy consumption is very high, it can create considerable economic benefits when dealing with high concentration waste liquid, but the current efficiency would drop significantly with the decrease in Cu2+ concentration, which limits the popularization and application of electrolytic method in low concentration wastewater treatment. Microbial fuel cell(MFC) is a device directly converting chemical energy into electricity with the microbial metabolism. Using current generated by the MFC instead of the traditional power in the electrolytic to treat the copper-containing wastewater, which solve the problem of high energy consumption of copper-containing wastewater treatment by electrolysis.This research used organic wastewater as anode substrate,mixed bacteria in activated sludge as anode microbial inoculation,and Cu SO4 wastewater as catholyte. Double chamber microbial fuel cells(MFCs) were constructed. The effects of electrode, membrane, load and temperature on the electricity generation capacity of MFC were studied. The results show that the electricity production of MFC which using activated carbon/graphite rod as electrode is optimal and the maximum power density was 6.9 m W·m-2. When the electrode distance of MFC was 2 cm, the maximum power density was 48.4 m W·m-2 and the electricity production of MFC improves with the increase of surface area of the electrodes. The electricity production of MFC is optimal when using Nafion117 membrane. The electricity production of MFC improves with the increase of surface area of the membrane. With the increasing of external resistance of MFC, the output voltage of MFC increases and the output current is decreased constantly. The MFC production performance is optimal when 25℃, the maximum power density was 4.8 m W·m-2.The experiment investigates the MFC anode organic wastewater treatment and its production performance. The experiments used 1000 mg·L-1 sucrose, 1000 mg·L-1 sodium acetate, 1000 mg·L-1 Aminoform as anode substrate, respectively. The results show that the production performance is optimal using sodium acetate as anode fuel. MFC production performance increases with the increase of the anolyte concentration. Adding phosphate buffer solution could greatly improve the production capacity of MFC, the maximum current density could up to 4.44 m A·m-2. The removal rate of COD can reach about 60~80%. Using microscope, transmission electron microscope to observe anode biofilm, it was found that there exist zoogloea, protozoa and metazoans in the anolyte.The experiment investigates the effect of MFC treatment of simulated wastewater containing copper. The experiments used 5000 mg·L-1 Cu SO4, 5000 mg·L-1 Cu Cl2, 5000 mg·L-1 Cu(NO3)2 as catholyte, respectively, double room microbial fuel cells(MFCs) were constructed. The results show that the production performance is optimal using Cu SO4 as catholyte. MFC production performance increases with the increase of the catholyte concentration. The removal rate of Cu2+ can reach about 80%~92%. Sediment on cathode plate detected by XRD is mixture of Cu and Cu2 O and Cu2+ content could reach about 74%~85%.The experiment constructed five MFC reactor, SMFC, H-type MFC, double room MFC, U-type MFC, baffled membrane-less double room MFC. The results show that the production performance of SMFC is best and the production performance of H-type MFC is lowest. These MFCs can effectively treat wastewater containing copper, but SMFC can not recycle copper. Using scanning electron microscope to observe sediment, surface morphology is mainly flower and dendritic. The average particle size of copper powder is about 1000 nm~2000 nm. Continuous-flow and intermittent-flow double chamber MFCs were constructed. The electricity production of continuous-flow MFC is slightly better than intermittent flow MFC. The experiment used copper slag leaching liquor as catholyte to start the MFC device successfully, the maximum power density could up to 1.33 m W·m-2 and the removal rate of Cu2+ can reach 88.5%. |
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