College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, China.
Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
Chemosphere. 2022 Jan;287(Pt 2):132247. doi: 10.1016/j.chemosphere.2021.132247. Epub 2021 Sep 13.
Chemical park is regarded as a major contributor of VOCs emissions in China. Currently, a green and safe technology, microbial fuel cells (MFCs), is being developed for the VOCs abatement. Noting that effective electron transfer is critical to the MFC performance. In this work, flavin mononucleotide (FMN) was dosed as an electron shuttle to improve the removal of the typical toxic VOCs, toluene. The experimental results revealed that the performance of toluene removal and power generation were accelerated with the dosage of 0.2-2 μM FMN. With the addition of 1 μM FMN, the removal efficiency, the maximum output voltage and the coulombic efficiency of MFC were increased by 18.4%, 64.4% and 56.3%, respectively. However, a further increase in FMN concentration to 2 μM caused a reduction in the removal efficiency and coulombic efficiency. The images of scanning electron microscopy and confocal laser scanning microscopy showed that the presence of FMN greatly promoted the microbial growth and its activity. Furthermore, microbial community analysis also implied that the moderate dosage of FMN (0.2-1 μM) was beneficial for the growth of the typical exoelectrogens, Geobacter sp., and thus the coulombic efficiency was increased. In addition, an electron transfer pathway involving in cytochrome b, OMCs, cytochrome c, and MtrA was proposed based on the cyclic voltammetry analysis. This work will provide a fundamental theoretical support for its application of toxic VOCs abatement from the chemical park.
化工园区被认为是中国 VOCs 排放的主要贡献者。目前，一种绿色安全的技术——微生物燃料电池（MFC）正在被开发用于 VOCs 的减排。鉴于有效的电子传递对 MFC 的性能至关重要。在这项工作中，黄素单核苷酸（FMN）被用作电子穿梭体，以提高去除典型有毒 VOCs（甲苯）的效率。实验结果表明，随着 FMN 剂量从 0.2 到 2 μM 的增加，甲苯的去除效果和发电性能得到了加速。添加 1 μM FMN 后，MFC 的去除效率、最大输出电压和库仑效率分别提高了 18.4%、64.4%和 56.3%。然而，当 FMN 浓度进一步增加到 2 μM 时，去除效率和库仑效率降低。扫描电子显微镜和共聚焦激光扫描显微镜的图像表明，FMN 的存在极大地促进了微生物的生长和活性。此外，微生物群落分析也表明，适量的 FMN（0.2-1 μM）有利于典型的外电菌（Geobacter sp.）的生长，从而提高了库仑效率。此外，基于循环伏安分析，提出了一个涉及细胞色素 b、OMCs、细胞色素 c 和 MtrA 的电子传递途径。这项工作将为其从化工园区去除有毒 VOCs 的应用提供基本的理论支持。
