Fe3O4 supported on water caltrop-derived biochar toward peroxymonosulfate activation for urea degradation: the key role of sulfate radical

作者：Li, Guang; Cao, Xiao-qiang^*; Meng, Na; Huang, Yi-meng; Wang, Xu-dong; Gao, Yuan-yuan; Li, Xuan; Yang, Ting-shu; Li, Bo-lai; Zhang, Yi-zhen; Lyu, Xian-jun; Liang, Yue

来源：Chemical Engineering Journal, 2022, 433: 133595.

DOI：10.1016/j.cej.2021.133595

• Urea
• Carbon material
• Peroxymonosulfate (PMS)
• Radical pathway
• Degradation

A new type of iron-doped and porous biochar (Fe@BC) derived from water mit rap was systematically investigated to catalyze the organic pollutants degradation by peroxymonosulfate (PMS). The effectiveness of this novel material was tested by treating excessive urea concentrations in swimming pool water. It exhibited good PMS activation capacity, achieving urea removal of 100% within 15 min. The Fe@BC/PMS system exhibited excellent resistance to common anions. Only chloride showed a small inhibitory effect, and the removal efficiency of urea decreased by 10% ([Cl-](0) = 10 mM). Quenching experiments and electron paramagnetic resonance spectroscopy analyses demonstrated that urea degradation was mainly mediated by the radical pathway, which in turn was dominated by surface-bound sulfate radicals (SO4 center dot-). Further, reusability experiments confirmed the stability of the material. After three cycles, the degradation efficiency can still reach 86%. Therefore, the conversion of water caltrop-derived biochar into a composite catalytic material provides a novel strategy for value-added utilization of aquatic waste biomass, and it is also a promising alternative for the treatment of urea from swimming pool water.

• 单位
  山东大学