Oral, ÖzlemKantar, ÇetinYıldız, İlker2024-02-212024-02-212024Oral, Ö., Kantar, Ç., Yıldız, İ. (2024) Influence of pyrite on oxidative treatment of diclofenac with zero-valent iron/H2O2 system coupled with chemical precipitation under controlled and uncontrolled pH conditions. Journal of Cleaner Production, 438. doi: 10.1016/j.jclepro.2024.1408690959-6526https://doi.org/10.1016/j.jclepro.2024.140869https://hdl.handle.net/20.500.12428/5715Batch experiments, combined with surface measurements, were conducted to elucidate the impact of pyrite on diclofenac treatment by zero-valent iron (ZVI)/H2O2 system. In binary systems with ZVI/H2O2, diclofenac removal was limited under controlled-pH conditions due to the agglomeration of ZVI particles and low rate of iron leaching. However, the use of pyrite in batch systems under uncontrolled-pH conditions drastically increased diclofenac removal by the ZVI/H2O2 system due to a significant drop in pH and enhanced iron dissolution. The diclofenac removal by the ternary ZVI/pyrite/H2O2 system could be explained through a combined effect of adsorption, oxidative degradation of diclofenac with hydroxyl radicals (*OH) and chemical precipitation of diclofenac and/or its intermediate species with the iron species dissolved from the ZVI/pyrite particles. While adsorption/chemical precipitation accounted for 75% of diclofenac removal in the initial stage, oxidative degradation achieved the remaining 25% diclofenac removal in the second stage. Surface analyses show that, in systems with diclofenac, the iron species dissolved from ZVI and pyrite particles complexed with diclofenac and/or intermediate species to form some spherical particles. Overall, this study sheds light on the reaction mechanism for the practical application of the ternary ZVI/pyrite/H2O2 system to diclofenac removal.eninfo:eu-repo/semantics/closedAccessChemical precipitationDegradationDiclofenacFentonPyriteZero-valent ironArticle43810.1016/j.jclepro.2024.140869WOS:0011715467000012-s2.0-85183154776