Effects of Manganese Carbonate Addition on the Carbocatalytic Properties of Lignocellulosic Waste for Use in the Degradation of Acetaminophen

A carbon-based material was synthesized using potato peels (BPP) and banana pseudo-stems (BPS), both of which were modified with manganese to produce BPP-Mn and BPS-Mn, respectively. These materials were assessed for their ability to activate peroxymonosulfate (PMS) in the presence of MnCO₃ to degrade acetaminophen (ACE), an emerging water contaminant. The materials underwent characterization using spectroscopic, textural, and electrochemical techniques. Manganese served a dual function: enhancing adsorption properties and facilitating the breaking of peroxide bonds. Additionally, carbonate ions played a structural role in the materials, transforming into CO₂ at high temperatures and thereby increasing material porosity, which improved adsorption capabilities. This presents a notable advantage for materials that have not undergone de-lignification. Among the materials tested, BPS exhibited the highest efficiency in the carbocatalytic degradation of ACE, achieving a synergy index of 1.31 within just 5 min, with 42% ACE degradation in BPS compared to BPS-Mn, which achieved 100% ACE removal through adsorption. Reactive oxygen species such as sulfate, hydroxyl, and superoxide anion radicals were identified as the primary contributors to pollutant degradation. In contrast, no degradation was observed for BPP and BPP-Mn, which is likely linked to the lower lignin content in their precursor material. This work addressed the challenge of revalorizing lignocellulosic waste by highlighting its potential as an oxidant for emerging pollutants. Furthermore, the study demonstrated the coexistence of various reactive oxygen species, confirming the capacity of carbon-based matrices to activate PMS.