Efficient degradation of trimethoprim with ball-milled nitrogen-doped biochar catalyst via persulfate activation

초록

This study explored a novel eco-friendly metal-free biochar catalyst for trimethoprim (TMP) degradation in an aqueous solution. The preparation of a ball-milled and N-doped mulberry biochar (BMNMB) for the activation of persulfate to degrade an antibiotic. BMNMB exhibits a large contact surface area and high colloidal stability compared to pristine biochar, ball-milled, and thermally treated biochar (BMMB). Surface analysis studies confirmed the heteroatom doping of the ball-milled biochar materials. The degradation efficiency of TMP in the BMNMB900/PS (>97%) was higher than those of the BMMB900/PS (73%) and pristine MB/PS (24%) systems. The TMP removal treads were further verified by the pseudo-first-order kinetic model (PFOKM). The effective degradation of TMP was obtained under neutral pH conditions. The heterogeneous catalytic reaction performance was examined using the Langmuir-Hinshelwood (L-H) kinetic model. The anions had a negative impact on the catalytic activation of BMNMB900 with PS. The chemical scavenger analysis was confirmed via both radical (HO" and SO4"- ) and non-radical (1O2) reactive oxygen species (ROS) formed in the BMNMB900/PS system. Further, substantial evidence of 1O2 formation in the BMNMB900/PS system was observed in the electron spin resonance (ESR) analysis in the presence of D2O. Moreover, the linear sweep voltammogram also clearly demonstrated the electron transfer process in the BMNMB900/PS system. The TMP degradation mechanisms were proposed via the intermediate analysis using ultra-high-performance liquid chromatography with mass spectroscopy (UHPLC-MS/MS). The BMNMB900 catalyst with PS system successfully demonstrated the reusability of a catalyst in TMP degradation.

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