Electro-biocatalytic treatment of petroleum refinery wastewater using microbial fuel cell (MFC) in continuous mode operation

- Contaminants present in refinery wastewater treated in continuous mode MFC operation.
- Continuous mode operation showed higher performance (225 ± 1.4 mW/m2) over batch mode.
- GC chromatogram showed significant removal of hydrocarbon content of C6 to C40.
- Phenol and sulfide removal was also significant in continuous mode operation.
- Projected power yields showed the possibility of process up-scaling.

Refinery wastewater (RW) treatment in microbial fuel cell (MFC) was studied in batch mode operation followed by continuous mode operation with 8 h and 16 h hydraulic retention time (HRT). The MFC performance was evaluated in terms of power density, organics removal, specific contaminants (oil & grease, phenol and sulfide) removal and energy conversion efficiency with respect to operation mode. Higher power density of 225 ± 1.4 mW/m2 was observed during continuous mode operation with 16 h HRT along with a substrate degradation of 84.4 ± 0.8% including the 95 ± 0.6 of oil content. The columbic efficiency during this operation was about 2 ± 0.8% and the projected power yield was 340 ± 20 kW h/kg CODR/day. Batch mode operation also showed good substrate degradation (81 ± 1.8%) but took longer HRT which resulted in significantly low substrate degradation rate (0.036 ± 0.002 kg CODR/m3-day) over continuous mode operation (1.05 ± 0.01 kg CODR/m3-day). Overall, current study depicted the possibility of utilizing RW as substrate in MFC for power generation along with its treatment.

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