Enhanced Acetaminophen Degradation via Peroxymonosulfate Activation Using Cu-FeOOH Catalyst

In recent years, increasing pharmaceutical consumption associated with population growth and aging has raised concerns regarding the accumulation of pharmaceutical contaminants in aquatic environments. Acetaminophen, a widely used antipyretic and analgesic drug, is frequently detected in water systems because it is not completely removed by conventional wastewater treatment processes. Therefore, the development of efficient water purification technologies is required.

Advanced oxidation processes (AOPs), which activate peroxymonosulfate (PMS) to generate sulfate radicals (SO₄•⁻), have attracted considerable attention for the degradation of organic pollutants. Compared with hydroxyl radicals (•OH), SO₄•⁻ exhibits higher oxidation potential, longer lifetime, and greater selectivity, making it highly effective for degrading refractory organic compounds. However, the development of highly active catalysts for efficient PMS activation remains a significant challenge.

In this study, a Cu-modified FeOOH catalyst was synthesized and evaluated for the degradation of acetaminophen. The degradation efficiency increased with increasing Cu loading, and the 70% Cu-FeOOH catalyst exhibited the highest catalytic activity. In addition, the degradation rate increased with increasing PMS concentration, indicating efficient PMS activation by the 70% Cu-FeOOH catalyst. Investigation of the effect of initial pH revealed that acidic conditions enhanced the degradation performance, with the highest activity observed at pH 5. These results suggest that the reaction environment strongly influences the generation of reactive species. Radical scavenging experiments indicated that singlet oxygen (¹O₂) was the dominant reactive species, suggesting that non-radical pathways play a significant role in the degradation process. Furthermore, the catalyst could be readily recovered using an external magnetic field and maintained high catalytic activity during reuse tests.