Junyan Kuang, Qishi Si, Wanqian Guo, Fang Ma

State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology

HaiJuan Guo

School of Environment, Liaoning University

Abstract

A highly dispersed catalyst (Fe₃O₄/NFe) was prepared with Fe3O4 and natural goethite (NFe) to remove TC in the heterogeneous Fenton-like system. A large amount of ≡Si–O–Si on NFe could be destroyed by the grinding method to produce ≡SiO• on the surface. Fe₃O₄ nanoparticles were successfully grown on the NFe with the formation of Fe–O–Si bonds, the Fe₃O₄/NFe retained the magnetic performance and the larger dispersion from predecessors. In the Fe₃O₄/NFe/H₂O₂ process, the degradation performance of tetracycline (TC) could reach 90.1% in 30 min. Moreover, the toxicity of TC and its intermediates was estimated in ECOSAR software. The ESR analysis and quenching experiments revealed the contribution of •OH, HO₂•, and ≡SiO• in TC removal. A part of •OH, HO₂• in solution could decompose TC, and the ≡SiO• on surface also directly remove TC. The strong interactions of Fe–O–Si bonds improved the generation of abundant •OH, and the total concentration of •OH by Fe₃O₄/NFe in 30 min is 244.7 μmol/L. In DFT analysis, the electrons redistribution between Fe₃O₄ and NFe could easily provide the electrons to activate H₂O₂, and improved the adsorption of H₂O₂ in Fe₃O₄/NFe/ H₂O₂ system. The removal rate of TC still reached 73.3% by Fe₃O₄/NFe after five cycles. In the present work, this Fe₃O₄/NFe has been shown to be a promising alternative to traditional homogeneous Fenton method.

Read the full article here:   68-Highly dispersed natural Goethite Fe3O4 heterogeneous Fenton like catalyst for efficient tetracycline degradation Rapid accumulation of hydroxyl radicals by Fe O Si bonds.pdf