The modeling of gold recovery from tetrachloroaurate wastewater using a microbial fuel cell

► Cost-effective gold recovery with a rate as high as 99.89 ± 0.00% was achieved. ► The highest maximum power density of 6.58 W/m2 was achieved for a 60 mL catholyte. ► The maximum power density can be predicted simply by measuring Rint by EIS. ► Anodic concentration polarization quenching supports a mediator mechanism. ► The equation was derived to calculate the maximum actual MFC efficiency.