Efficient ranitidine removal using Si3N4-ZVI/PAA system: Mechanistic insights and environmental implications

In this study, silicon nitride-zero-valent iron (Si 3 N 4 -ZVI) powders were obtained through post-milling and employed as a catalyst to activate peracetic acid (PAA) for the removal of Ranitidine (RAN). The system achieved an impressive 90.4 % of degradation efficiency, with a pseudo-first-order kinetic reaction constant 11.3 times higher than that of the ZVI/PAA system. Quenching experiments and Electron Paramagnetic Resonance (EPR) analysis confirmed that both radical and non-radical processes are involved in RAN degradation within the Si 3 N 4 -ZVI/PAA system. Moreover, the identified ten degradation products are less toxic compared to the byproducts from alternative oxidation methods reported by prior literature. The proposed degradation pathway of RAN includes C S cleavage, oxygenation/hydroxylation demethylation, and denitrification. Furthermore, the Si 3 N 4 -ZVI/PAA system showed effectively in treating RAN-contaminated surface water, artificial wastewater, and dissolved organic matter, demonstrating its great ability in treating diverse organic-contaminated water sources. In conclusion, results of this study suggest that the Si 3 N 4 -ZVI/PAA system possess high pollutant removal efficiency, broad applicability, and less environmental and health risks.