Co-substrate-Assisted Dimethyl Sulfide Degradation and Electricity Generation in a Microbial Fuel Cell

Dimethyl sulfide (DMS) emitted from the petrochemical industry is a typical volatile organic sulfur compound (VOSC) with poor solubility and odorous smell. A microbial fuel cell (MFC) is regarded as an appreciative method for simultaneous DMS degradation and electricity generation. In this work, for the first time, we developed an MFC system for DMS treatment. With an initial concentration of 95 mg L-1, the DMS removal efficiency at the closed-circuit state was achieved as high as 89.5% within 40 h, which was 1.21 times higher than that at the open-circuit state. The maximum power density and current density were 0.237 mW m(-2) and 2.644 mA m(-2), respectively. The dominant electrogenic bacteria in the MFC were Stenotrophomonas, Pseudomonas, and Candidatus Microthrix, and the DMS degraders included Thiobacillus, Truepera, and Candidatus Microthrix. Direct extracellular electron transfer was involved in the bioanode for DMS degradation according to the CV curves. Moreover, to overcome the toxicity of high-concentration DMS on microorganisms and enhance power generation, sodium acetate (NaAc) was added as a co-substrate, resulting in 52.5% increase in DMS degradation activity and a 16.5 times higher maximum output voltage. Overall, these findings may offer basic information for bioelectrochemical degradation of DMS and facilitate the application of MFCs in waste gas treatment.

Automated summary

A microbial fuel cell (MFC) system was developed for efficient degradation of DMS and simultaneous electricity generation. Dominant electrogenic bacteria and DMS degraders were identified in the MFC, and the addition of sodium acetate as a co-substrate significantly enhanced DMS degradation activity and output voltage.