Separation and Purification Technology, Vol.132, 346-353, 2014
Removal of 2,4-dichlorophenol from contaminated soil by a heterogeneous ZVI/EDTA/Air Fenton-like system
The removal of 2,4-dichlorophenol (2,4-DCP) from contaminated soil by an amino carboxylic acid-enhanced zero-valent iron/Air (ZVI/Air) Fenton-like system has been performed in this study. The effects of ethylenediaminetetraacetic acid (EDTA) and ethylenediamine-N,N'-disuccinic acid (EDDS) on the catalytic degradation of 2,4-DCP were primarily studied in the presence of ZVI catalyst and O-2 oxidant. The result indicated that the degradation of 2,4-DCP in ZVI/Air system was hindered by EDDS but enhanced by EDTA. Complete destruction of 2,4-DCP in contaminated soil was achieved in the heterogeneous ZVI/EDTA/Air (ZEA) Fenton-like system under ambient air and room temperature. ZVI and EDTA were the predominant factors influencing the degradation of 2,4-DCP. The degradation of 2,4-DCP was ascribed to heterogeneous catalytic reaction over the ZVI surface in situ modified by EDTA via the formation of monodentate inner-sphere complexes. In this system, two main reactive oxygen species of O-2(center dot-)/HO2 center dot and Fe(IV) were generated, in which O-2(center dot-)/HO2 center dot was predominant. The novel ZEA oxidation system provides a promising eco-friendly alternative for the remediation of contaminated soils. (C) 2014 Elsevier B.V. All rights reserved.