Protons accumulation during anodic phase turned to advantage for oxygen reduction during cathodic phase in reversible bioelectrodes.
Protons accumulation during anodic phase turned to advantage for oxygen reduction during cathodic phase in reversible bioelectrodes.
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DOI：
10.1016/j.biortech.2014.09.076
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发表时间：
2014-12
影响因子：
11.4
通讯作者：
E. Blanchet;Sophie Pécastaings;B. Erable;C. Roques;A. Bergel
中科院分区：
文献类型：
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作者：
E. Blanchet;Sophie Pécastaings;B. Erable;C. Roques;A. Bergel
可逆生物电极是通过交替供应乙酸盐和氧气而设计的。结果表明，当电极切换为生物阴极时，阳极阶段在生物膜内产生和积累的质子极大地有利于氧还原反应。阻碍生物阳极运行的质子积累因此成为生物阴极的优势。生物阳极由花园堆肥渗滤液在 -0.2 V vs. SCE 的恒定极化下形成，能够支持长时间暴露于强制通风，其阳极效率仅略有变化。他们为乙酸盐氧化产生了 16 ± 1.7 A/m2 的电流密度，为氧还原产生了高达 -0.4 A/m2 的电流密度。通过 16S rRNA 焦磷酸测序对微生物群落进行的分析显示，Chloroflexi 具有很强的选择性 (49 ± 1%)，而在未暴露于氧气的传统生物阳极中未观察到这种情况。首次发现 Chloroflexi 作为电活性生物膜的优势门。
Reversible bioelectrodes were designed by alternating acetate and oxygen supply. It was demonstrated that the protons produced and accumulated inside the biofilm during the anodic phase greatly favored the oxygen reduction reaction when the electrode was switched to become the biocathode. Protons accumulation, which hindered the bioanode operation, thus became an advantage for the biocathode. The bioanodes, formed from garden compost leachate under constant polarization at −0.2 V vs. SCE, were able to support long exposure to forced aeration, with only a slight alteration of their anodic efficiency. They produced a current density of 16 ± 1.7 A/m2for acetate oxidation and up to −0.4 A/m2for oxygen reduction. Analysis of the microbial communities by 16S rRNA pyrosequencing revealed strong selection of Chloroflexi (49 ± 1%), which was not observed for conventional bioanodes not exposed to oxygen. Chloroflexi were found as the dominant phylum of electroactive biofilms for the first time.