Enhancing the bioremediation by harvesting electricity from the heavily contaminated sediments

•A 100 L SMFC was operated in heavily contaminated sediment for over 2 years.•The sediments could provide sufficient electron donors for long-term SMFC operation.•SMFC–PMS system is a durable and efficient tool in bioremediation and power-supply.

To test the long-term applicability of scaled-up sediment microbial fuel cells (SMFCs) in simultaneous bioremediation of toxic-contaminated sediments and power-supply for electronic devices, a 100 L SMFC inoculate with heavily contaminated sediments has been assembled and operated for over 2 years without external electron donor addition. The total organic chemical (TOC) degradation efficiency was 22.1% in the electricity generating SMFCs, which is significantly higher than that in the open-circuited SMFC (3.8%). The organic matters including contaminants in the contaminated sediments were sufficient for the electricity generation of SMFCs, even up to 8.5 years by the present SMFC theoretically. By using a power management system (PMS), the SMFC electricity could be harvested into batteries and used by commercial electronic devices. The results indicated that the SMFC–PMS system could be applied as a long-term and effective tool to simultaneously stimulate the bioremediation of the contaminated sediments and supply power for commercial devices.