2015/4/30 · The voltage output (power density) for the carbon flake cathode and Pt-loaded carbon paper cathode was 384 ± 16 mV (44.4 ± 2.5 mW/m 2) and 399 ± 9 mV (44.1 ± 3 mW/m 2 ), respectively. The percentage of COD reduction at the anode region and effluent was above 75 and 85 %, respectively, for all cathode materials.