Enhanced dechlorination of 2,4-dichlorophenol by recoverable Ni/Fe-Fe3O4 nanocomposites

Cancan Xu; Rui Liu; Lvjun Chen; Jialu Tang

doi:10.1016/j.jes.2015.10.033

Enhanced dechlorination of 2,4-dichlorophenol by recoverable Ni/Fe-Fe₃O₄ nanocomposites

J Environ Sci (China). 2016 Oct:48:92-101. doi: 10.1016/j.jes.2015.10.033. Epub 2016 Mar 25.

Authors

Cancan Xu¹, Rui Liu², Lvjun Chen³, Jialu Tang⁴

Affiliations

¹ Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environment, Yangtze Delta Region Institute of Tsinghua University, Zhejiang, Jiaxing 314006, China. Electronic address: xucancan523127@163.com.
² Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environment, Yangtze Delta Region Institute of Tsinghua University, Zhejiang, Jiaxing 314006, China. Electronic address: liuruitsinghuazj@gmail.com.
³ Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environment, Yangtze Delta Region Institute of Tsinghua University, Zhejiang, Jiaxing 314006, China; School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: chenlj@tsinghua.edu.cn.
⁴ Zhejiang Provincial Key Laboratory of Water Science and Technology, Department of Environment, Yangtze Delta Region Institute of Tsinghua University, Zhejiang, Jiaxing 314006, China.

PMID: 27745676
DOI: 10.1016/j.jes.2015.10.033

Abstract

Ni/Fe-Fe₃O₄ nanocomposites were synthesized for dechlorination of 2,4-dichlorophenol (2,4-DCP). The effects of the Ni content in Ni/Fe-Fe₃O₄ nanocomposites, solution pH, and common dissolved ions on the dechlorination efficiency were investigated, in addition to the reusability of the nanocomposites. The results showed that increasing content of Ni in Ni/Fe-Fe₃O₄ nanocomposites, from 1 to 5wt.%, greatly increased the dechlorination efficiency; the Ni/Fe-Fe₃O₄ nanocomposites had much higher dechlorination efficiency than bare Ni/Fe nanoparticles. Ni content of 5wt.% and initial pH below 6.0 was found to be the optimal conditions for the catalytic dechlorination of 2,4-DCP. Both 2,4-DCP and the intermediate product 2-chlorophenol (2-CP) were completely removed, and the concentration of the final product phenol was close to the theoretical phenol production from complete dechlorination of 20mg/L of 2,4-DCP, after 3hr reaction at initial pH value of 6.0, 3g/L Ni/Fe-Fe₃O₄, 5wt.% Ni content in the composite, and temperature of 22°C. 2,4-DCP dechlorination was enhanced by Cl^- and inhibited by NO₃^- and SO₄^2-. The nanocomposites were easily separated from the solution by an applied magnetic field. When the catalyst was reused, the removal efficiency of 2,4-DCP was almost 100% for the first seven uses, and gradually decreased to 75% in cycles 8-10. Therefore, the Ni/Fe-Fe₃O₄ nanocomposites can be considered as a potentially effective tool for remediation of pollution by 2,4-DCP.

Keywords: 2,4-Dichlorophenol; Catalytic dechlorination; Common dissolved ions; Ni/Fe-Fe(3)O(4) nanocomposites; Recoverable.

MeSH terms

Chlorophenols / chemistry*
Environmental Restoration and Remediation / methods*
Ferrous Compounds / chemistry*
Halogenation
Nanocomposites / chemistry*
Nickel / chemistry*
Waste Disposal, Fluid / methods
Water Pollutants, Chemical / chemistry*

Substances

Chlorophenols
Ferrous Compounds
Water Pollutants, Chemical
Nickel
ferrous oxide
2,4-dichlorophenol