Cu-Fe-Ni layered hydroxides / magnetic biochar composite as peroxymonosulfate activator for removal of enrofloxacin

In this research, an economical peroxymonosulfate (PMS) was employed as the oxidizing agent, while a sophisticated Cu-Fe-Ni layered hydroxides/magnetic biochar composite (MBC/CuFeNi LDHs, succinctly termed MC-1) functioned as a catalyst to mitigate the presence of enrofloxacin (ENR), a notably toxic contaminant discerned in water. The stratified architecture and intricate surface functional groups of the composite played pivotal roles in ENR's degradation. Metal oxides containing Cu, Fe, and Ni particularly exhibit excellent catalytic performance and oxygen storage capacity. The introduction of magnetic biochar (MBC) can reduce the aggregation of CuFeNi, and the rich functional groups on the surface of MBC can increase the content of functional groups on the surface of the composite, which helps to activate PMS. To be more precise, an impressive 91.6% of ENR was abated by the MC-1&PMS ensemble within a mere 20 min. Moreover, the catalytic dynamism of the MC-1&PMS synergy was predominantly ascribed to the production of hydroxyl (∙OH) radicals, complemented by sulfate (SO4∙-), singlet oxygen (1O2), and superoxide radicals (∙O2-). In the ensuing discourse, a conceivable degradation trajectory for ENR was postulated. Overall, this investigation furnishes novel perspectives in the conceptualization of heterogeneous carbon catalysts within the realm of advanced oxidation techniques.