*3.2. Mustard Tuber and Molasses Wastewater*

Mustard tuber processing is often known to generate a large volume of effluent, with the wastewater being of high strength and salinity. A case study was observed when a two-chambered MFC was employed to treat mustard tuber wastewater, recording a Pdmax of about 246 mW/m<sup>2</sup> , including 67% and 85% of CE and COD removal [74]. On the other hand, molasses are broadly employed in many research fields and are usually derived from sugarcane mills. It is usually considered a rich source of sugar and minerals such as Ca, including vitamins. It contains a high COD concentration, which varies from 60–100 g/L and thus acts as a major pollutant from the sugarcane processing factories. When the diluted molasses wastewater is used in MFCs, a 62 mW/m<sup>2</sup> power density was recorded, whereas 81% of COD was removed using a mixed inoculum [75]. A generated bioelectricity of 0.18 W/m<sup>2</sup> was recorded from an MFC treating sugarcane molasses whereby *Brevibacillus borstelensis* STRII was used [76]; additionally, there was an increase in power density when the sugarcane molasses concentration was increased. This demonstrates a promising way to manage the substrates in wastewater and energy generation whereby MFC integration in dark fermentation processes can result in positive environmental outcomes [77]. Table 2 summarizes some of the agricultural product processing wastewater used in MFC technology for its treatment and CE.


