Effects Of Different Environmental Factors On Bacterial Diversity Of MEC Anode Biofilm

Hydrogen energy is a clean and efficient secondary energy source,and microbial electrolytic cell technology(MEC)can use renewable resources such as wastewater to produce hydrogen.Degradation of organic matter in waste contributes to environmental protection.In the entire MEC fermentation system,electroactive microorganisms dominate.In order to explore the effects of different environmental factors on the hydrogen production performance,bacterial diversity,and distribution of dominant bacteria in MEC anode biofilms,The single factor test method is used to regulate different environmental factors.Batch MEC anode biofilm culture experiments and hydrogen production potential verification experiments are performed in a single-cell MEC reactor with variable electrode distance.During the cultivation process,the electrolytic current,hydrogen content,electricity,Chemical activity,etc.were measured.After the anode biofilm was cultivated,the membrane biomass and hydrogen yield were measured.The bacterial diversity of the anode biofilm and the culture solution after the cultivation was sequenced.Finally,all the data were analyzed in different environments.The relationship among factors,MEC hydrogen production performance,bacterial diversity,and dominant flora.At the same time,a simple comparative analysis of the bacterial diversity and distribution of dominant communities in the MEC anode biofilm and the culture broth was made.The conclusion is as follows:When the electrolytic voltage is 0.8 ~ 1.2V,the temperature is 35 degrees Celsius,the culture environment is neutral,the inoculation amount is 30%,and the initial glucose concentration is 5 g / L,the smaller the electrode distance and the external load,using glucose as a substrate MEC has the best hydrogen production performance,and sodium acetate?sodium propionate?sodium butyrate and glucose are all suitable for MEC hydrogen production;Under different environmental factors,the hydrogen production performance of MEC is positively related to the abundance of the dominant electroactive bacteriaClostridium ? Geobacter ? Desulfovibrioand Desulfuromonas.Among them,the hydrogen production performance and MEC under different external load ?temperature?initial pH?and inoculation volume,the bacterial diversity of the anode biofilm is positively correlated;under different electrolytic voltage,electrode distance,and substrate conditions,the hydrogen production performance is not directly related to the diversity of the MEC anode biofilm;under different glucose concentration conditions,the hydrogen production performance is related to the anode Negative correlation of bacterial diversity in biofilms;Not all of the dominant bacteria on the surface of the anode biofilm are electroactive bacteria;the microbial diversity of the culture solution is generally greater than the diversity of the anode biofilm cultured under the same conditions,and the abundance of the dominant electrolysing bacteria on the MEC anode biofilm is uniform.Larger than the culture medium,the culture medium contains a small amount ofClostridium?Desulfovibrio?Desulfuromonas,and the amount of Geobacter in the culture medium is little or no;from the perspective of the few dominant bacteria,the abundance of Bacteroidete's abundance medium MEC anode biofilm,while the abundance of Actinobacteria,Firmicutes,and Proteobacteria is anode biofilm> culture fluid;...