Polyphenol Oxidase from Agricultural Wastes for Dye Removal from Wastewater

This research addresses the urgent global need for the safe and economical removal of dyes from wastewater. We assessed the efficacy of polyphenol oxidase (PPO) extracted from different agricultural residues in removing reactive blue dye, marking the initial endeavor to do so. PPOs isolated and refined from rice straw, corn stover, peanut peels, olive husk, date core, and potato peels were examined. Optimal conditions for dye removal, comprising an enzyme concentration of 0.5 U/mL and a 10-min incubation period, were identified for all PPOs. Potato peels emerged as the most abundant source of PPO, displaying the highest dye removal efficiency at around 93.89%. Remarkably, this efficiency was consistent across a wide temperature range (20–80 °C) and a broad pH range (4–9), with no adverse effects noted in the presence of heavy metals. Comparative analysis highlighted potato peels as the most promising waste reservoir, highlighting resilience under diverse conditions. These findings provide valuable insights into utilizing PPO from agricultural waste for effective dye removal, offering potential applications in addressing environmental concerns within industrial settings.