文献类型：期刊文献

英文题名：Alkali synergistic sulfide-modified nZVI activation of persulfate for phenanthrene removal

作者：Tan, Yixin[1];Zhao, Nan[1,2];Song, Quanwei[3];Ling, Hao[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]CSCEC 8th Div Environm Technol Co Ltd, CSCEC Ecoenvironm Engn Res Ctr Soil Remediat Techn, Shanghai 200444, Peoples R China;[3]China Natl Petr Corp, Res Inst Safety & Environm Technol, Beijing 102206, Peoples R China

年份：2023

卷号：11

期号：3

外文期刊名：JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING

收录：;EI(收录号：20231613903092);WOS:【SCI-EXPANDED(收录号:WOS:001042676400001)】；

基金：This study was supported by the National Key Research and Devel- opment Program of China (Grant No. 2019YFC1806004) and the Soil Remediation Technology and Equipment of Eco-Environmental Engi- neering Research Center (CSCEC-PT-009) .

语种：英文

外文关键词：Sulfide -modified zero-valent iron; Persulfate; Phenanthrene; Alkali; Electronic conduction

摘要：Sulfide-modified nano zero-valent iron (S-nZVI) and persulfate (PS) have been widely used in advanced oxidation processes, whereas their performance in alkaline solutions is rarely discussed. In this study, the synergistic activation mechanism of S-nZVI with alkali is proposed and verified by removal experiments and activator characterization. nZVI and S-nZVI with different sulfidation degrees were prepared and used to enhance PS oxidation for phenanthrene (PHE) removal. Results indicate that the S/Fe ratio significantly affects PHE degradation, with the optimal ratio at 0.28. S-nZVI exhibits superior degradation rates to nZVI over a wide pH range (3  11), especially in alkaline solutions with a maximum removal rate of 94.7% at pH = 9. At the same time, the relative synergistic enhancement ratio shows a maximum value of 1.80. Hydroxyl radicals are identified as the main active groups. X-ray photoelectron spectroscopy results suggest that the alkaline solutions promote the conversion of S2-, which increases from 24.7% to 33.1% compared to neutral solutions. Furthermore, the electrochemical tests of S-nZVI and nZVI reveal that S-nZVI has lower electron transfer impedance and higher oxidation peak current density at pH = 9, which probably elucidates that the alkali accelerates the electron conductivity of S-nZVI. These findings, for the first time, demonstrate the alkali synergistic activation mechanism of S-nZVI/PS systems and provide a deeper insight into the efficient degradation of persistent organic pollutants in complex pH environments.