Enhanced Nitrobenzene reduction by zero valent iron pretreated with H2O2/HCl

• Published in: Chemosphere (Oxford) Vol. 197; pp. 494 - 501
• Main Authors: Yang, Zhe, Ma, Xiaowen, Shan, Chao, Fang, Zhuoyao, Pan, Bingcai
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2018
• Subjects: H2O2; Nitrobenzene; Pharmaceutical wastewater; Pretreatment; Reductive degradation; Zero valent iron; Reductive degradation; Pharmaceutical wastewater; Nitrobenzene; Pretreatment; H2O2; Zero valent iron
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.01.068

In this study a novel iron-based reducing agent of highly effective reduction toward nitrobenzene (NB) was obtained by pretreating zero valent iron (ZVI) with H2O2/HCl. During the H2O2/HCl pretreatment, ZVI undergoes an intensive corrosion process with formation of various reducing corrosion products (e.g., Fe2+, ferrous oxides/hydroxides, Fe3O4), yielding a synergetic system (prtZVI) including liquid, suspensions and solid phase. The pretreatment process remarkably enhances the reductive performance of ZVI, where a rapid reduction of NB (200 mg L−1) in the prtZVI suspension was accomplished in a broad pH range (3–9) and at low dosage. Nitrosobenzene and phenylhydroxylamine are identified as the intermediates for NB reduction with the end-product of aniline. Compared with the virgin ZVI as well as another nanosized ZVI, the prtZVI system exhibits much higher electron efficiency for NB reduction as well as higher utilization ratio of Fe0. A rapid reduction of various nitroaromatics in an actual pharmaceutical wastewater further demonstrated the feasibility of the prtZVI system in real wastewater treatment. [Display omitted] •prtZVI is capable of reducing nitrobenzene efficiently.•prtZVI exhibited much higher utilization ratio and electron efficiency than ZVI.•Nitrobenze was removed via a step-by-step reduction.•The applicability of prtZVI was demonstrated by treating a pharmaceutical effluent.