Performance and Anode Bacterial Community Analysis in Different Substrates Powered Microbial Fuel Cell
|School||Dalian University of Technology|
|Keywords||Microbial fuel cell Wheat straw biomass Fulvic acid Denaturing gradient gel electrophoresis 16S rDNA gene analysis|
The microbial fuel cell (MFC) is the use of microbial degradation of organic waste chemical energy into electrical energy as a catalyst. MFC system, electricity production microorganisms is a core element of the anode substrate (fuel) and inoculum source will directly affect the types of microorganisms producing electrical properties of electricity production. Dosing different substrates, especially the real substrate MFC, the study of microbial community structure of electricity production, for understanding the different substrate conditions of MFC power production mechanism has some theoretical significance. The two-bedroom MFC device to study the feasibility of the hydrolyzate of wheat straw as a the MFC fuel production power, and characterization of the anode producing electricity flora in the evolution of the entire operation cycle. The results showed that the hydrolyzate concentration of 1000mg-COD / L when, MFC maximum power density of up to 123 mW / m 2 sup> (364 mA / m 2 sup>). The power density changes with the the hydrolyzate initial concentration Monod empirical formula can be used to describe. The maximum power density for P max = 152.2 mW / m 2 sup>, K s = 284.9 mg-COD / L. The coulombic efficiency of 15.5% to 37.1%. Biofilm and suspended bacteria in the electricity production process. Complex substrate under the action of bacteria in the suspension fermentation simple small molecules fermentation product, the fermentation product of these small molecules electricity production bacteria in the biofilm further advantage of producing electricity. 16S rDNA library analysis showed that the The anode biofilm predominant is the Bacteroidetes bacteria Programme microorganisms (40%), followed by Alphaproteobacteria (20%), Bacilli (20%), Deltaproteobacteria (10%) and Gammaproteobacteria (10%). Suspended bacteria predominant the Bacteroidetes Hymenomycetes (44.4%), followed by Alphaproteobacteria (22.2%), Bacilli (22.2%), Betaproteobacteria (11.2%). Fermented and non-fermented substrate evolution and power output of the MFC community. Fermentation substrate glucose start MFC change plus the non-fermented substrate sodium acetate, genus producing electricity enrichment, a significant increase in power output. Sodium acetate after adding glucose to change the initial substrate, an anode microbial community structure changed significantly, MFC need an acclimation period (about 4 days) in order to restore the electricity production. Anode flora did not change significantly after the the sodium butyrate start MFC change on the same type of substrate sodium acetate, producing electrical properties unaffected. The mixed substrate start of MFC power production performance is lower than separate substrate start MFC to achieve longer required by the stability of the microbial community structure. The \Fulvic acid (FA) on the MFC power output and electricity production process. FA (0-2000 mg / L) Add to improve the power density and coulombic efficiency of 8.3 to 56.7% and 20.5 ~ 33.5%. FA change the metabolic pathways of the substrate caused by a metabolic intermediate changes in the proportion of acetic acid and ethanol, acetic acid was significantly increased.