Performance and mechanism of innovative two-phase partitioning microbial fuel cell for effective propanethiol treatment

A two-phase partitioning microbial fuel cell (TPPMFC) was first time constructed to enhance the mass transfer and removal efficiency of hydrophobic volatile organic sulfur compounds by adding silicone particles as solid non-aqueous phase. The results indicated that the output voltage was gradient increased with the concentration of selected mode propanethiol increased from 100 mg/L to 500 mg/L, but the complete degradation cycle of PT was extended from 12 h to 78 h. The obvious enhancement of microbial fuel cell performance was achieved with 2 % (v/v) 0.4 mm silicone particle. The output voltage increased by 95.6 % +/- 12 %, the removal efficiency of 500 mg/L of propanethiol increased from 67 % +/- 3 % to 91 % +/- 4 % within 24 h, and the maximum power density was 26.23 mW/m2 (72.5 % improvement). The live microorganism on the anodic biofilm was maintained at 95 % after a long-term operation, which was benefited from the fluid shear force caused by agitated anolyte and solid non-aqueous phase. Moreover, the dominant microbial in the TPPMFC were Pseudomonas, sulfatereduced Aquamicrobium, and Acinetobacter, and the propanethiol was biodegraded by them via two different pathways compared with the traditional ones. Finally, the mechanisms of propanethiol removal and power generation in the TPPMFC were analyzed. It is believed that the results provide insight into the application of two-phase distribution technology for the removal of hydrophobic volatile organic compounds in bioelectrochemical systems.

Automated summary

A two-phase partitioning microbial fuel cell (TPPMFC) was constructed with silicone particles as solid non-aqueous phase, which enhanced the mass transfer and removal efficiency of hydrophobic volatile organic sulfur compounds. The addition of 2 % 0.4 mm silicone particles significantly improved the performance of the microbial fuel cell, with a 91 % removal efficiency of 500 mg/L of propanethiol achieved within 24 hours.