*3.4. Winery Wastewater*

Winery wastewater with different compositions was tested using MFCs made up of two single-chamber air cathodes [80]. A wire made up of titanium along with carbon fiber was put in place of generic anodes, while on the other hand, cathodes were made up of platinum-coated carbon cloth of 0.4 mg Pt/cm<sup>2</sup> . The white wine wastewater resulted in less promising results with an energy generation capacity of 263 mW/m<sup>2</sup> ; albeit a significant quantity of COD (90%) and BOD (95%) removal was achieved with a CE of 15%. Comparatively, red wine wastewater had 111 W/m<sup>2</sup> , with a recorded 27% COD removal, whereas a maximum BOD removal of 83% was achieved; hence, a lower CE of 9% was observed. These experiments indicated that different wastewater, even from the same industry, can have different usable substrates with differentiated compositional characteristics, which determines the MFC's power output. This was facilitated by diverse and different microbial populations found in the anode; besides, the negative influence on MFC performance was due to a high concentration of polyphenolic compounds in some winery wastewater.
