| For a long time, anaerobic and aerobic biological treatment of sewage water is the main method of sewage treatment. Due to its expensive cost and the restrictions of high concentrations sewage water, the traditional method has been affected by global energy shortage and has also become the obstacles of China’s further economic development. The microbial fuel cell technology is a new technology of sewage treatment, which can purify sewage water and be access to get output power at the same time. Microbial fuel cells technology has attracted close attention from international academic community, is regarded as a high efficiency, low power consumption, clean and environmentally friendly processing technology.This article is to study the characteristics of the DCMFC for piggery sewage water which is based on the new achievement of MFC and the COD treatment efficiency, power-producing capacity, the assessment and analysis of indicators.The results show DCMFC will start to work after three months’cycling by inoculating black grain which can generate electrical bacteria sludge and gathering. There will be two excellent repeatable power generating cycle, which is similar to microbial metabolism. The polarization curves show the maximum output power is220mW/m2(5.50mW),the apparent internal resistance is19.56Ω which corresponds to Hyperbl theoretical counting result.It is tested for DCMFC with stable operation under the conditions of50Ω by selecting the different external resistances of50Ω5Ω and500Ω, and it is found that the external resistance increases to the bigger one, the greater the output voltage (36.70mV to670.00mV), the smaller the current (1.30to14.00mA), the greater the internal resistance (0.72to8.20Q), the greater the cathode electrode potential (-380.00to156.00mV), the greater the anode electrode potential (-407.00mV to525.00mV), the higher the COD removal rate (53.38percent to61.35percent), the smaller the coulombic efficiency (7.19percent to40.89percent),the higher the cell efficiency (3.16percentto47.55percent), the higher the non-electricity bacteria energy loss rate (59.11percent to92.81percent).When the external resistance is 50Ω,the power is highest(5.51mW), loading rate is highest(0.150.34kgm-3d-1), the energy efficiency is also highest (4.24percent). Excessively big or small external resistance are not conducive to DCMFC electrical properties.Different external resistance of DCMFC under the stable operation of50Ω outside resistance, its cathode and anode electrode potential, the output voltage and current influence law with the resistance can be fitted by ExpDecl model to the intendedsynthesis equation y=y0+Ae-x/t, the ideal external resistance range of options is among80Ω to500Ω.Under the conditions of fixtures, structures, materials, external resistance and temperature conditions, the run impacted factors of DCMFC are studied and analyzed, including the type of anode substrate, anode substrate concentration, electron acceptor and buffer. Experimental studies have shown that the appropriate operating conditions of DCMFC are as follows:anode substrate of glucose, the substrate concentration of COD1000mg/L or more, buffer solution of CBS=9.60, the electron acceptor of ferricyanide,[Fe(EDTA)]Na can be used as a recycling of electronicreceptor usage at the same time. After the adjustment and optimization of run of the various operating conditions, it draws that its producing electrical properties is18.38mW (PA735.00mW/m2,I=35.00mA)and the resistance is10.41Ω;At the same time, the COD removal and production of electrical properties law of the DCMFC in dealing with the simulated and actual swine Wastewater are dicussed in this paper. The tests shows that when DCMFC deals with simulated wastewater with glucose initial concentration1683.33mg/L, the COD removal efficiency is81.96percents and the coulombic efficiency is13.22percents, the cell efficiency is37.99percents, the load rate is0.38kgm-3d-1, the stable output power is3.09mW,and the anode substrate daily effluent COD processing efficiency and the laws of the substrate COD concentration changing over time can be fitted by ExpDec1model to describe the fitting correlation coefficient, respectively0.99632and0.98744. And when dealing with COD concentration of actual farms wastewater of933.70mg/L, it has a well treatment effect, it turns out that the output power of2.85mW (114mW/m2), electricity production duration of98.1h, COD removal rate of67.87percents, Coulomb19.82percents efficiency and energy utilization rate of6.00percents cell efficiency of44.62percents, the load rate of0.24kgm-3d-1, and the substrate COD removal efficiency with the time variation of can use ExpDecl model to describe the fitting correlation coefficient of up to0.99935.In addition, DCMFs of series or parallel combinations are discussed in this paper. It turns out that serious voltage reversal phenomenon happens on unlike DCMFCs of series combination,resulting in the failure of which disadvantaged DCMFC and not presenting after the superposition of the battery law. Parallelling two ones that are not synchronized to deal with the actual wastewater will reduce the energy efficiency itself, and bring the phenomenon of "mutual raiding".Finally DCMFC is improved, and a detailed study of the electricity law of the improved DCMFC in treating different kinds of high concentrations of simulated wastewater process, resulting in getting the maximum output power density in the initial COD concentration of each substrate and using Hyperbl model to fit it,and the fitting coefficient is0.89535, the maximum power of myopia value is6.35mW (253.81mW/m2), which is however less than the maximum power density of original DCMFC which is723.84mW/m2. Also COD removal and production of electrical properties law are discussed in improved DCMFC of simulated and actual swine Wastewater and swine Wastewater treatment, it comes to deal with the1867.3Omg/L farms simulated wastewater output power of3.58mW(143.20mW/m2), electricity production duration of213.90h, COD removal rate of77.83percents, the coulombic efficiency of18.89percents, the energy utilization rate of5.86percents and39.84percents cell efficiency, the load rate of0.17kgm-3d-1and the anode substrate daily effluent COD processing efficiency and the laws of the substrate COD concentration changing over time can use ExpDecl model to describe the fitting correlation coefficient of0.99328and0.97656, respectively. Improved DCMFC processing1093.34mg/L actual swine wastewater with maximum output power of2.74m W (PA=109.41mW/m2,1=5.30mA) energy to handle1466.66mg/L actual wastewater output power of4.36mW (174.40mW/m2), electricity production duration of148.40h average internal resistance of3.40Ω when the water, the COD removal rate reaches to73.26percents, the coulombic efficiency of21.49percents, the energy utilization rate of8.40percents, the cell efficiency of53.36percents, the loadrate0.18kgm-3d-1, and the daily effluent total COD treatment efficiency and the laws of the substrate COD concentration changing over time can use ExpDecl model to describe the fitting correlation coefficient of0.99683and0.99782, respectively. |
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