Sulfate Radicals Destroy Pharmaceuticals and Personal Care Products

Presence of persistent and toxic pharmaceuticals and personal care products (PPCPs) in water bodies has generated considerable scientific, regulatory, and public interests, requiring the development of cost-effective technologies for PPCP treatment. This study reports that sulfate radical (SR)-based advanced oxidation technologies (AOTs) are promising as a new environmental risk management option for PPCP-contaminated water. Triclosan, sulfamethoxazole, and acetaminophen were effectively decomposed and mineralized by the attack of SRs generated through the activation of peroxymonosulfate (PMS) and persulfate with iron. The PMS/Fe system was more effective than persulfate/Fe but less effective than the H2O2/Fe (Fenton reaction) system that produces hydroxyl radicals. However, when conjugated with cobalt, PMS showed outstanding reactivity toward PPCPs, whereas negligible decomposition of PPCPs by H2O2 was observed. Insights and suggestions on PPCP decomposition by SRs are also discussed, including organic selectivity and system stability. As an alternative to established hydroxyl radical-based AOTs, SR-based AOTs should initiate new strategic plans to manage PPCPs and other emerging chemicals of concern in water resources.