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Ascorbic acid/Fe@Fe2O3: A highly efficient combined Fenton reagent to remove organic contaminants

2016; Elsevier BV; Volume: 310; Linguagem: Inglês

10.1016/j.jhazmat.2016.01.020

1873-3336

Xiaojing Hou, Xiaopeng Huang, Zhihui Ai, Jincai Zhao, Lizhi Zhang,

Environmental remediation with nanomaterials

In this study, we demonstrate that the combination of ascorbic acid and [email protected]2O3 core–shell nanowires (AA/[email protected]2O3) offers a highly efficient Fenton reagent. This combined Fenton reagent exhibited extremely high activity on the decomposition of H2O2 to produce OH for the degradation of various organic contaminants, including rhodamine B, methylene blue, alachlor, atrazine, siduron, lincomycin, and chloroamphenicol. The contaminant degradation constants in the AA/[email protected]2O3/H2O2 Fenton systems were 38–53 times higher than those in the conventional homogeneous Fenton system (Fe(II)/H2O2) at pH 3.8. Moreover, the OH generation rate constant in the AA/[email protected]2O3/H2O2 Fenton system was 1–3 orders of magnitudes greater than those of heterogeneous Fenton systems developed with other iron-containing materials (α-FeOOH, α-Fe2O3, FeOCl, and so on). The high activity of AA/[email protected]2O3 was attributed to the effective Fe(III)/Fe(II) cycle and the iron-ascorbate complex formation to stabilize ferrous ions with desirable and steady concentrations. During the AA/[email protected]2O3/H2O2 Fenton process, ascorbic acid served as a reducing and complexing reagent, enabling the reuse of [email protected]2O3 nanowires. We systematically investigated the alachlor and ascorbic acid degradation and found that they could be effectively degraded in the AA/[email protected]2O3/H2O2 system, accompanying with 100% of dechlorination and 92% of denitrification. This study sheds light on the importance of Fe(III)/Fe(II) cycle for the design of high efficient Fenton system and provides an alternative pathway for the organic contaminants removal.