“…The removal of hydrocarbons in soil is correlated with bio-current generated by exoelectrogenes (Li et al, 2014b;Lu et al, 2014a;Zhang et al, 2014). Using MFCs to remediate sediment contaminated by hydrocarbons, the degradation rate increased by up to 12 times from 2% to 24% in 66 d. However, according to the low power density reported previously (an average of 37 mW m À3 ), the system heavily suffered from very high internal resistance of $4 kX, mainly attributed to the high Ohmic resistance as a result of low conductivity in soil (Morris and Jin, 2012).…”