Innovative Wastewater Treatment: Dismantling Naproxen with Cavitation and Plasma Discharge

This study investigates the degradation of Naproxen in wastewater using a treatment method involving cavitation and plasma discharge. The significance of this method is emphasized in light of the increasing contamination of wastewater with pharmaceuticals. The experimental results demonstrate the capability of the system to degrade Naproxen in water, as confirmed by High-Performance Liquid Chromatography (HPLC) analysis. The primary mechanism behind Naproxen degradation involves the generation of radicals, charged particles, forces, and heat through plasma and hydrodynamic cavitation, leading to oxidation and bond cleavage. The study suggests that oxidative degradation, driven by the generated radicals, is the primary cause of Naproxen breakdown. Various proposed Naproxen degradation products indicate potential reactions involving oxygen radicals and hydroxyl groups. The effectiveness of the treatment increases with longer exposure, generating more radicals and facilitating increased Naproxen degradation. The treated samples exhibited a decrease in total peak area with longer treatment times, possibly due to the formation of undetected products or the evolution of gases like carbon dioxide. Additional peaks in chromatograms, especially after prolonged treatment, posed challenges in peak assignment. Further observations revealed ongoing oxidation even after five days of storage, suggesting delayed or persistent degradation, possibly due to remaining radicals or slow-reacting substances.