Using Lime (Citrus × aurantiifolia), Orange (Citrus × sinensis), and Tangerine (Citrus reticulata) Waste as a Substrate for Generating Bioelectricity

Abstract

This paper focuses on using lime, orange, and tangerine waste as fuel for the generation of bioelectricity. The tangerine microbial fuel cell evidenced a maximum voltage peak of 1.1 V on day 13, while displaying abrupt voltage losses on the following days and throughout the remaining period of substrate monitoring. On the other hand, orange-based fuel denotes lower current generation during these 28 days with values close to 1.6 mA and 0.25 mA on the first and last day, respectively. Still, orange generated 3.5 mA on the first day with values sharply declining in the following days until reaching 0.91 mA on the last day. In general, substrate volumes in the microbial fuel cells diminished over time, which is consistent with the voltage and current values reported. In addition, pH values increased from day 1 for all substrates, reaching acidic pH values on the last day of measurement due to the consumption of carbon sources. Tangerine reported the highest current density (CD) at 72 mW/cm2 and a maximum voltage of 1.06 volts, while orange generated a CD of 62.5 mW/cm2 and 0.94 volts.