Single-chamber microbial fuel cells (MFCs) using domestic wastewater (DWW) and milk processing
wastewater (MWW) were operated at different organic loading rates (OLRs). The maximum power density
(PDmax) and OLR (readily biodegradable COD [RBCOD] and soluble COD [SCOD]) followed the
Lineweaver?Burk equation in all influents. The coefficients of determination were 0.9209 and 0.9975
for SCOD and RBCOD, respectively. OLR based on RBCOD showed better power generation function than
that based on SCOD. PDmax (2.9?12.2 W/m3) in DWW was lower than that (6.9?24.9 W/m3) in MWW but
the net energy recovery (kWh/kg-SCODremoved) in DWW (0.542?1.108) was larger than that in MWW
(0.322?0.602). This was attributed to the higher ratio of RBCOD/SCOD (0.44) and the lower values of
RBCOD (40 mg/L) in DWW, compared to RBOCD/SCOD (0.11) and RBCOD (110 mg/L) in MWW.
Therefore, RBCOD is an important indicator for estimating power generation.
