Microbial fuel cell-enhanced electrokinetic process for remediation of chromium from marine sediments

The combination of microbial fuel cell with electrokinetic processes, known as Microbial Electrokinetic Cell (MEKC), is an innovative and sustainable process for simultaneous sediment remediation and renewable energy production. This study made a major contribution to research on MEKC by demonstrating the maximum energy extraction and chromium removal using three types of the anode electrode, comprising plate graphite (PG), scratched plate graphite (SPG), and the combination of SPG with granular activated carbon (SPG-GAC) used as bioanode. The results indicated that power generation changed noticeably based on the anolyte type and electrode configuration. The application of the SPG-GAC electrode resulted in the maximum power densities of 10 +/- 0.02 and 5.12 +/- 0.04 W/m(3)in MEKCs fed by actual and synthetic wastewater, respectively. However, feeding MEKC with synthetic wastewater instead of the actual one caused a slight reduction in chromium removal from 72.64 to 69.50% in anode and from 53.70 to 49.44% in cathode chamber. According to the obtained results, the SPG-GAC can be suggested to improve MEKC power generation by increasing bacterial adhesion and enhancing the extracellular electron transfer using the granular activated carbon. Furthermore, the results provided a proof-of-concept that MEKC has a high potential to be used for efficient sediment remediation and to promote environmental health.