Abstract

Reducing fuel cells electrical losses is achieved by the use of a catalyst. Being inexpensive and renewable, biocathodes have an advantage over synthetic and chemical ones. Here the microbial fuel cell (MFC)-utilizing biocathode based on the acidophilic chemolythotrophic microorganisms (ACM) mixed culture has been studied. The Leptospirillum sp., Acidithiobacillus sp., Ferroplasma sp. consortium has been used as a cathode biocatalyst. Pyrite enrichment tails of a mining and processing enterprise served as the catholyte substrates. It is experimentally demonstrated that ACM mixed culture Leptospirillum sp., Acidithiobacillus sp., Ferroplasma sp. introduced into the catholyte leads to MFC electrical characteristics increase by approximately two times. With the selected external load (30 Ω) Cathodic bioagents increased the MFC electric power four-fold (from 137 to 579 µW). Catholyte redox potential increased from 431 to 581 mV during 11 d in the presence of acidophilic iron-oxidizing microorganisms. At 33 d, this value increased up to 695 mV. This is an indirect evidence for active processes of iron oxidation. The analysis results for the Fe³⁺ content in the medium also support this assumption. Thus, in a course of a 33-d experiment Fe³⁺ concentration increased from 0 to 1.5 g/l. The redox processes intensification in the studied systems also confirmed by the cyclic voltammetry (CV). Under pyrite utilization conditions in the presence of ACM mixed culture cyclic voltammograms show an increase in the reduction current at the cathodic potentials region. The results obtained herein suggest that the studied biochemical system is a perspective catholyte for MFC capable to reduce a cathodic overpotential.

摘要

减少燃料电池的电损耗是通过使用催化剂来实现的。生物阴极价格便宜且可再生，相对于合成和化学而言具有优势。在这里，已经研究了基于嗜酸性化学营养型微生物（ACM）混合培养的利用微生物燃料电池（MFC）的生物阴极。该钩端螺旋体菌，嗜酸菌，铁原体属。财团已被用作阴极生物催化剂。采矿和加工企业的硫铁矿富集尾巴用作阴极电解液的底物。实验证明，ACM混合培养是钩端螺旋体，酸性硫杆菌，铁原体。sp。引入到阴极电解液中会导致MFC的电气特性提高大约两倍。在选择了外部负载（30Ω）的情况下，阴极生物制剂将MFC的电功率提高了四倍（从137 µW到579 µW）。在嗜酸性铁氧化微生物存在的11天内，阴极电解液的氧化还原电势从431 mV增加到581 mV。在第33天，该值增加到695 mV。这是铁氧化活跃过程的间接证据。介质中Fe ³⁺含量的分析结果也支持该假设。因此，在33天的实验过程中，Fe ³⁺浓度从0增加到1.5 g / l。循环伏安法（CV）也证实了所研究系统中氧化还原过程的增强。在黄铁矿利用条件下，在存在ACM的情况下，混合培养物的循环伏安图显示出阴极电位区域的还原电流增加。本文获得的结果表明，所研究的生化系统是能够降低阴极超电势的MFC的透视阴极电解液。