The soil microbial fuel cell (SMFC) has been widely used for soil remediation for its low cost and being eco-friendly. But low degradation efficiency and high mass transfer resistance limit its performance. This study constructed a solar cell-soil microbial fuel cell (SC-SMFC) with different voltages, which use clean energy to improve system performance. At different voltages, 2.0-V system showed the best performance and the maximum output power increased by 330% compared with SMFC. Moreover, 2.0-V SC-SMFC showed the fastest phenol degradation rate of 14 μg·mL-1·d-1 at the concentration of 80 μg/mL, which was twice of SMFC. Further increasing the concentration to 320 μg/mL, the system showed extremely high concentration limit and degraded 90% within 19 days. Under this condition, SC-SMFC still showed excellent cycle stability, with the third-round degrading 90% phenol in 13 days. Finally, electrochemical impedance spectroscopy (EIS) mechanism study showed that solar cells can accelerate microbial metabolic process and reduce the internal resistance, in which the 2.0-V system was only 87% of SMFC. In conclusion, SC-SMFC provides a green, low-cost, and convenient method for in situ soil remediation in the future.
Keywords: Clean energy; Organic pollutants; Phenol degradation; Soil microbial fuel cell; Soil remediation; Solar cell.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.