Superior dimethyl disulfide degradation in a microbial fuel cell: Extracellular electron transfer and hybrid metabolism pathways

• Published in: Environmental pollution (1987) 2022-12, Vol.315, p.120469-120469, Article 120469
• Main Authors: Zhao, Jingkai, Gao, Jialing, Jin, Xiaoyou, You, Juping, Feng, Ke, Ye, Jiexu, Chen, Jianmeng, Zhang, Shihan
• Format: Article
• Language: English
• Subjects: Dimethyl disulfide; Extracellular electron transfer; Metabolism pathway; Microbial fuel cell; Sulfur balance
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.120469

To enhance the biological degradation of volatile organic sulfur compounds, a microbial fuel cell (MFC) system with superior activity is developed for dimethyl disulfide (DMDS) degradation. The MFC achieves a removal efficiency near 100% within 6 h (initial concentration: 90 mg L−1) and a maximum biodegradation rate constant of 0.743 mM h−1. The DMDS removal load attains 2.684 mmol h−1 L−1, which is 6.18–2440 times the loads of conventional biodegradation processes reported. Meanwhile, the maximum power density output and corresponding current density output are 5.40 W m−3 and 40.6 A m−3, respectively. The main mechanism of extracellular electron transfer is classified as mediated electron transfer, supplemented by direct transfer. Furthermore, the mass balance analysis indicates that methanethiol, S0, S2−, SO42−, HCHO, and CO2 are the main intermediate and end products involved in the hybrid metabolism pathway of DMDS. Overall, these findings may offer basic information for bioelectrochemical degradation of DMDS and facilitate the application of MFC in waste gas treatment. Dimethyl disulfide (DMDS), which features poor solubility, odorous smell, and refractory property, is a typical pollutant emitted from the petrochemical industry. For the first time, we develop an MFC system for DMDS degradation. The superior DMDS removal load per unit reactor volume is 6.18–2440 times those of conventional biodegradation processes in literature. Both the electron transfer route and the hybrid metabolism pathway of DMDS are cleared in this work. Overall, these findings give an in-depth understanding of the bioelectrochemical DMDS degradation mechanism and provide an efficient alternative for DMDS removal. [Display omitted] •The feasibility of MFC system for DMDS degradation was validated.•The DMDS removal load attained as high as 2.684 mmol h−1 L−1 in the developed MFC.•The extracellular electron transfer was preferred to be mediated electron transfer.•The hybrid metabolism pathway of DMDS and functional microorganisms were cleared.