Degradation of Tetracycline with Fe1mg2-Bc as a Persulfate Activator: Performance and Reaction Mechanism

Abstract

Herein, a novel tetracycline (TC) removal strategy was established by activation of persulfate (PS) using Fe1Mg2-biochar (Fe1Mg2-BC), which was synthesized by wet impregnation method. Results revealed that TC elimination efficiency by Fe1Mg2-BC was significantly higher than those of BC and FeMg binary oxides, which may possibly result from the synergy of BC and FeMg binary oxides. Fortunately, Fe1Mg2-BC/PS method had an excellent ability for TC decomposition over a wide pH range of 3-11, and 87.3% of TC was removed after 60 min treatment. Several characterization methods were utilized to explore the properties of prepared materials. Quenching experiments and electron spin resonance (ESR) analyses confirmed that the superoxide radical (O2•−), followed by singlet oxygen (1O2) advanced TC degradation. The main degradation products were recognized by LC-MS measurement. Hence, the TC decomposition mechanism was proposed. Additionally, all the tests were also carried out in actual water samples. The results indicated that the Fe1Mg2-BC/PS system possessed the outstanding resistance for interferences in real water. This work proposes a new direction for the potential environmental applications of modified biochar.

Keywords: Biochar, Fe-Mg modification, Tetracycline, Persulfate