Electric field induced salt precipitation into activated carbon air-cathode causes power decay in microbial fuel cells
Electric field induced salt precipitation into activated carbon air-cathode causes power decay in microbial fuel cells
复制标题
电场诱导盐沉淀到活性炭空气阴极中导致微生物燃料电池的功率衰减
DOI：
10.1016/j.watres.2017.06.087
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发表时间：
2017-10-15
期刊：
影响因子：
12.8
通讯作者：
Wang, Xin
中科院分区：
文献类型：
--
作者：
An, Jingkun;Li, Nan;Wang, Xin
活性炭空气阴极作为微生物燃料电池（MFC）在废水处理领域真实的应用的一种有前途的设计，在长期运行后存在着严重的功率衰减问题。然而，由于污染物的复杂性质，其衰变机制仍然不清楚。与以往报道不同的是，我们发现局部碱化和自然蒸发对阴极性能的影响是可调和的（类似于电流密度的2%衰减），而电场诱导盐沉淀（类似于53%）和生物污损（类似于37%）根据电荷转移电阻占主导地位，在6个月内，功率密度从1286 +/- 30下降到822 +/- 23 mW m（-2），下降了36%。生物污垢可以通过刮除来去除，但电场诱导的生物膜下的盐沉淀仍然堵塞了催化剂层37%的比面积，甚至可以看到盐沉淀穿透了气体扩散层。我们的研究结果提供了一个新的见解，交流空气阴极性能衰减，提供了重要的信息，在未来的阴极寿命的改善。(C)2017爱思唯尔有限公司版权所有
As a promising design for the real application of microbial fuel cells (MFCs) in wastewater treatment, activated carbon (AC) air-cathode is suffering from a serious power decay after long-term operation. However, the decay mechanism is still not clear because of the complex nature of contaminations. Different from previous reports, we found that local alkalinization and natural evaporation had an ignorable effect on cathode performance (similar to 2% decay on current densities), while electric field induced salt precipitation (similar to 53%) and biofouling (similar to 37%) were dominant according to the charge transfer resistance, which decreased power desities by 36% from 1286 +/- 30 to 822 +/- 23 mW m(-2) in 6 months. Biofouling can be removed by scrapping, however, electric field induced salt precipitation under biofilm still clogged 37% of specific area in catalyst layer, which was even seen to penetrate through the gas diffusion layer. Our findings provided a new insight of AC air-cathode performance decay, providing important information for the improvement of cathodic longevity in the future. (C) 2017 Elsevier Ltd. All rights reserved.