Lanthanum-Doped Magnetic Biochar Activating Persulfate in the Degradation of Florfenicol

Abstract

In this study, lanthanum-doped magnetic biochar (LaMBC) was synthesized by co-doping elements with lanthanum as the magnetic biochar (MBC), and it was characterized for its application in the activation of PS in the degradation of florfenicol (FLO). The results were indicated that the LaMBC/PS system consistently achieved a degradation efficiency of over 99.5%, with a reaction rate constant 4.71 times as that of MBC. The mechanism of FLO degradation suggested that O2•- and •OH played dominant roles, contributing 40.92% and 36.96%, respectively, during FLO degradation. Through physicochemical characterization and quenching experiments, it can be concluded that the key reasons for the enhancement of MBC activation performance are as follows: (1) Lanthanum doping in magnetized biochar increases the Fe(Ⅱ) content in MBC. (2) Lanthanum doping significantly improves the adsorption capacity of LaMBC, increasing the concentration of pollutants on the catalyst surface and effectively enhancing the reaction rate. (3) Lanthanum doping effectively increases the surface Fe(Ⅱ) content during the reaction process in LaMBC, promoting the generation of active oxygen species in PS. This study not only provides a novel approach for the treatment of antibiotic organic pollutant wastewater but also contributes to the understanding of the mechanisms behind rare earth metal element-enhanced activation of PS by MBC.

Keywords: magnetic biochar、persulfate、FLO、lanthanum