Study On The Resource Of Treating Wastewater Containing Copper With Microbial Fuel Cell

Copper mine, mining, smelting, electroplating industry and the electronicsindustry annually emit large quantities of wastewater containing copper, the emissionsof heavy metals copper ion has great harm to water and soil. Copper is also a preciousmetal, its recovery from wastewater has a high economic value. The microbial fuel cell（MFC） is a decontamination capacity of new technologies which can convert theorganic matter into electricity using the anaerobic microorganism as catalyst. MFC canbe applied to treat the copper-containing wastewater, the copper ions is reduced at thecathode and elemental copper can be recovered. Therefore, no matter from sewage andpower generation, the removal of copper ions in the wastewater, reducing the pollutionof water bodies or from the recovery of precious metals elemental copper point of view,this discovery has important theoretical and practical significance. But at home andabroad for this technology is still in the study.The main research topics was different factors on the impact of electricityproduction performance and Cu²⁺removal with MFC processing wastewatercontainging copper, providing guidance for further improving the performance ofelectricity production,Cu²⁺removal effect and the practical application of MFCprocessing wastewater containing copper. In this study, the dual-chamber MFC devicewas used, using synthetic wastewater as anode chamber substrate, simulated copperwastewater with copper sulfate as cathode chamber electrolyte and the anaerobicmicroorganism as catalyst. In the study, the anode chamber concentration of thesubstrate and the initial concentration of Cu²⁺, plus sodium sulfate electrolyte, theinitial pH, concentration of hydrogen peroxide in cathode solution and the externalresistor, and respectively changing the distance between anode，cathode and proton exchange membrane （PEM） on the performance of electricity production and Cu²⁺removal of MFC. And the differences of electricity production was explored when fourkinds of heavy metal ions (Cu²⁺, Pb²⁺, Ag⁺, Cr6+)as electron acceptor of MFC.The study results showed that:（1） With cathode air aeration and liquid sulfuric acid of12water hydrogenphosphate dihydrate, sodium dihydrogen sulfate and sodium chloride electrolyte aselectrolyte of Anolyte, the reactors MFC was quickly started, after half a month, themaximum output voltage reaches310mV.（2） The range of COD concentration was185.9-1235.1mg/L, the higher the anodeCOD concentration, the higher Cu²⁺removal rate, but the lower the COD removalefficiency and coulombic efficiency, the output voltage increase is not obvious, undersome anolyte conditions, the maximumthe output power first increases rapidly withincreasing substrate concentration, and then slowly increased, the relationship betweenthe two correspond to the Monod equation. When anolyte Cu²⁺concentration was1600mg/Land the external resistance was1000ohm, obtained by fitting the highestoutput power density was209mW/m2and half-saturation constant （Ks） was125.58mg/L.（3） Cu²⁺concentration was60-1400mg/L, the higher the catholyte initial Cu²⁺concentration, the better the effect of producing electricity, the faster its own removalrate, but the lower removal efficiency of Cu²⁺; by cathodic reduction componentanalysis, the higher Cu²⁺concentration,the lower the cathodic reduction of force, lessconducive to generation of elemental Cu;Under low concentration of initial Cu²⁺,internal resistance of the battery was larger, the internal resistance of the battery can besignificantly reduced and its electricity production effects can be improved under lowconcentration of the copper-containing waste liquid by applying Na2SO4electrolyte.（4） When200mg/LH2O2exists, output voltage and output power was significantlyhigher than H2O2, but the Cu²⁺removal significantly reduced in pre-electricityproduction, while H2O2concentration was200mg/L, maximum output power densitywas114.1mW/m2that was increased by51.3%than H2O2was0mg/L, but notsignificantly lower the internal resistance of battery. The lower the pH of acidicwastewater containing copper, the higher the output power and voltage, but Cu²⁺ removal rate increased little.（5） Reduce the external resistor will help increase the output power, and cansignificantly improve the removal efficiency of Cu²⁺,while external resistor was0,after10h, the removal rate of Cu²⁺reached98.1%; lesssmall the cathode and the PEMspacing is more obvious on reducing the internal resistance of the battery andimproveing the production power-up and Cu²⁺removal rate than reducing the spacingof the anode and PEM, EIS results show that, when the the cathode and the PEMdistance decreases, the reduce of the internal resistance of the battery was mainlycaused by the reduce of the ohmic internal resistance of the battery.（6） Through using the campus life sewage as anode matrix to run the device,finding that the electricity production and removal of Cu²⁺effects was considerable asusing synthetic wastewater, We can conclude that it was feasible to treat actualdomestic sewage in the anode chamber and at the same time to remove Cu²⁺in thewater by cathodic reduction with this device.（7） Cu²⁺,Ag⁺, Cr6+, Pb²⁺four heavy metal ions were used as electron acceptors ofthe cathode, electricity production effect of Cr6+is the best, when its initialconcentration was200mg/L, the maximum output power density reached270mW/m2,the worst production electric is Pb²⁺, the higher of the heavy metal ion’ redo, the higherits producing electricity and the removal of metal ion.