初始pH值对MEC阳极膜的产氢性能和微生物群落的影响

Effect of initial pH on the performance and microbial community of MEC anode biofilms

实验采用单池微生物电解池(MEC)研究不同初始pH值(5,7,9)下形成的MEC阳极膜的产氢性能及微生物群落的变化。结果表明:在阳极膜形成过程中,各实验组的电流值和氢含量表现出正相关关系。pH值为7左右时的实验组有最佳的氢气产率(1.52 mol H2·mol^-1-G)和最大的氧化峰值电流(35.41mA),产氢效能高的反应器中电活性微生物优势较大。16SrDNA测序结果显示不同pH下形成的阳极膜的OTUs数分别为781、1156和953,pH为5和9下形成的阳极膜微生物多样性及微生物量较低。此外,MEC阳极膜上的占主导地位的产电菌均以Clostridium和Geobacter为主,但pH值为7左右时形成的阳极膜微生多样性、优势菌及生物量都最为丰富。

The experiment used a single-cell microbial electrolysis cell(MEC)to study the hydrogen production performance and microbial community changes of the MEC anode membrane at different pH values(5,7,9).The results show that during the formation of the anode film,the current value of each experimental group showed a positive correlation with the hydrogen content.The experimental group with a pH value of about 7 has the best hydrogen yield(1.52 mol H2·mol^-1-G)and the largest oxidation peak current(35.41mA).The reactor with high hydrogen production efficiency has a greater advantage in electroactive microorganisms.16SrDNA sequencing results showed that the number of OTUs of anode membranes formed at different pH was 781,1156 and 953,respectively,and the microbial diversity and microbial biomass of anode membranes formed at pH 5 and 9 were low.In addition,the dominant electro-producing bacteria on the MEC anode membrane are mainly Clostridium and Geobacter,but the microbial diversity,dominant bacteria and biomass of the anode membrane formed when the pH value is around 7 are the most abundant.