Goethite/biochar-activated peroxymonosulfate enhances tetracycline degradation: Inherent roles of radical and non-radical processes

• Published in: The Science of the total environment 2021-08, Vol.783, p.147102-147102, Article 147102
• Main Authors: Guo, Yanxiu, Yan, Liangguo, Li, Xuguang, Yan, Tao, Song, Wen, Hou, Tailei, Tong, Caili, Mu, Junli, Xu, Meng
• Format: Article
• Language: English
• Subjects: Advanced oxidation process; Antibiotics; Biochar; Goethite; Peroxymonosulfate
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.147102

While biochar supported iron materials have been widely studied in advanced oxidation processes (AOPs), little is known about the effect and mechanism of goethite/biochar in sulfate radical (SO4−) based AOPs. Herein, a novel goethite/biochar composite was applied as peroxymonosulfate (PMS) activator for tetracycline (TC) degradation in the water. The superior catalytic efficiency of goethite/biochar was achieved through radical (OH and SO4−) and non-radical (1O2) processes according to the radicals quenching experiments and electron paramagnetic resonance analysis. Carbonyl group and Fe species were the main active sites on the surface of goethite/biochar, which was demonstrated by combining Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and reaction kinetic experiments. Furthermore, nine main by-products of TC degradation were detected by liquid chromatography-mass spectrometry and the reasonable degradation pathway was proposed according to the molecular structure analysis. Overall, the goethite/biochar materials could be applied to activate PMS for TC degradation, and this study will benefit the application of iron/biochar materials in practical water treatment. [Display omitted] •Low-cost goethite/biochar was synthesized by a co-precipitation method.•The composite efficiently activated PMS to degrade TC.•Radical and non-radical processes had synergetic effect on TC degradation.•CO and Fe(II) species assisted in PMS decomposition.