Transformation by plasma technology of cisplatin found in hospital's wastewaters into platinum-containing nanoparticles

Abstract

Platinum-containing molecules such as cisplatin figure among oncology's most widely used antineoplastic agents. Cisplatin excreted in the urine usually ends up in municipal wastewater, with a strong toxicological and carcinogenic impact on the environment. Thus, cisplatin should be inactivated before reaching wastewater to attenuate its environmental impact. However, conventional recommended procedures use large quantities of toxic acids, which are not sustainable processes. In this study, a dielectric barrier discharge (DBD) atmospheric pressure plasma reactor is used to degrade cisplatin in wastewater, allowing platinum's recuperation. The article describes the plasma discharge (power, electron temperature, and density) and confirms the most stable operation parameters under Ar and Ar+H2 discharges. Cisplatin is diluted in water or synthetic urine, and plasma treatment is conducted for 30 min. The process degrades cisplatin molecules by conversion into platinum-rich nanoparticles (NPs). These nanoparticles are efficiently recuperated by centrifugation and are characterized by transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). The mass-balance assessment confirms that more than 90% of cisplatin is degraded and recuperated as Pt-rich NPs.