Application Study On Modification Of MFC Electrodes And Its Use In Wastewater Treatment

Microbial fuel cells give us new biochemical energy extraction technology,along with the biological treatment capacity electric microorganisms to convert chemical energy part of the organic matter contained into electrical energy,and bio-diesel,bio-production of oxygen,fuel ethanol and other biomass utilization mode phase ratio,has its unique advantages and characteristics,it is an optimized collection of renewable clean energy technologies.In this paper,microbial fuel cells is used to be studied,the use of chemical and electrochemical analysis and other research methods to study the different materials to prepare MFC electrode was modified investigated,its role and influence in the microbial fuel cell electricity generation process.Through research,the main conclusions were followd:?1?Preparation of a modified Hummers legal graphite oxide and ammonia-hydrazine compound prepared by reduction of graphene by XRD,SEM,TEM,FTIR analysis measuring results,preparation of graphene success,graphite oxidation process,the layer spacing changed from 0.337 nm to 0.816 nm,after reduction of graphite oxide layer spacing was reduced to 0.379 nm,graphene layer spacing was greater than graphite,indicating that ammonia-hydrazine reduction was not complete,contains a small amount of oxygen-containing groups.The obtained graphene layers thinner and more,the surface of a sheet-like pleated structure.Assay showed that graphene methyl orange has a good adsorption performance,when pH is 2,dosage is 15 mg,temperature is 45 ? w hen the best adsorption conditions,when adsorption capacity is 56.49mg/g;isothermal results showed that the adsorption,Langmuir and Freundlich isotherm equation could well describe graphene for methyl orange adsorption isotherms,but better correlation Langmuir isotherm equation.Adsorption enthalpy and entropy changes were 1427.3J/mol and 28.93 J/mol·K,the adsorption process was endothermic spontaneous;when graphene adsorption of methyl orange kinetic equation fitting,pseudo-second-order kinetic the high degree of fit with the pseudo-second-order reaction model more accurately describe graphene adsorption of methyl orange.The use of PTFE emulsion as a binder,graphene bonded to the carbon cloth prepared graphene modified electrodes.Then varying amounts of modified electrodes made of graphene electrochemical test results show that the electrochemical oxidation of graphite-modified electrode was improved,and the content of the high yield of graphene the electrical properties of the stronger,the highest rate of electron transfer,best conductivity.?2?one-step oxidation-reduction method successfully prepared manganese dioxide nano-particles,nano-electron microscopy results showed that manganese dioxide particle dispersion was better particle size of 10 20 nm.Surface area there were a lot of active-OH.Apply it and do Reactive Blue assay results showed that: when the nano manganese dioxide in an amount of 0.15 g,reactive brilliant blue KN-R concentration wastewater 20mg/L,pH=3,the processing time was 90 min,temperature 30?was the solution absorbance at a minimum.The use of PTFE emulsion as a binder,5% solution of Nafion and nano manganese dioxide particles bonded to the carbon cloth prepared graphene modified electrodes.Then varying amounts of modified electrodes made of graphene electrochemical test results indicate MnO₂ / Pt / C has a higher current density and better power output than the Pt / C.?3?Blend in the operation of the MFC,MnO₂ / Pt/C than Pt/C has a higher current density and better output power.MnO₂ may promote the introduction of Pt/C cathode with less oxygen activation on overvoltage for reduction reaction,thus increasing the MFC local performance.In the use of MFC of MnO₂ / Pt/C catalyst in the maximum power of 360 mw/m²,MFC than as cathode using Pt/C catalyst increased output by 104%.And can be seen from the change of pH in three different cathode MFC through life after treatment of wastewater pH from 6.15 to 8.75,9.43,9.75,after processing of pH value,reaction process of the show of similar electrochemical reaction.And the COD degradation rate after treatment with MFC produces to the corresponding to the production capacity of the battery,the higher of COD degradation rate was higher,the effect of wastewater treatment was the better.?4?the treatment of low coking wastewater with MFC,the platinum electrode COD treatment rate is 82.9%,COD treatment efficiency iron oxide electrode reaches 72.5%,COD treatment efficiency manganese dioxide electrode is 73.4%.Description use MFC low coking wastewater treatment feasibility large.Maximum current platinum electrode produced 0.0015 A,the maximum current density is 2.40A/m².Manganese dioxide electrode,the maximum current is 0.0012 A,the maximum current density is 2.06A/m².Maximum current iron oxide electrodes for 0.0011 A,the maximum current density is 1.79A/m²,and the COD degradation rate corresponds to higher electricity output higher COD degradation rate of wastewater,wastewater treatment,the better,composite theoretical requirements.By comparing these three cathode materials to the platinum electrode on the wastewater treatment effect was indeed superior to the other electrode,a platinum electrode,but the cost was too high,inexpensive materials iron oxide,manganese dioxide in electricity production with respect for platinum ability less than platinum electrode,but the sewage treatment effect is closer to legend inexpensive materials for the study of low coking wastewater treatment MFC has a certain value.In summary,the graphene itself has a strong adsorption capacity,and high electrochemical properties can be used for the use of MFC,was a good conductive material.Nano-particles modified manganese dioxide electrode can not only improve the performance of electricity production in the MFC run time,and can increase the efficiency of sewage treatment,indicating that nano manganese dioxide as the cathode catalyst MFC to meet operational requirements.