Preparation of functionalized Pd/Fe-Fe3O4@MWCNTs nanomaterials for aqueous 2,4-dichlorophenol removal: Interactions, influence factors, and kinetics

Jiang Xu; Zhen Cao; Xue Liu; Heng Zhao; Xi Xiao; Jiaping Wu; Xinhua Xu; John L Zhou

doi:10.1016/j.jhazmat.2016.04.063

Preparation of functionalized Pd/Fe-Fe3O4@MWCNTs nanomaterials for aqueous 2,4-dichlorophenol removal: Interactions, influence factors, and kinetics

J Hazard Mater. 2016 Nov 5:317:656-666. doi: 10.1016/j.jhazmat.2016.04.063. Epub 2016 Apr 26.

Authors

Jiang Xu¹, Zhen Cao², Xue Liu², Heng Zhao², Xi Xiao³, Jiaping Wu³, Xinhua Xu⁴, John L Zhou⁵

Affiliations

¹ State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China. Electronic address: jxu@sklec.ecnu.edu.cn.
² State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China.
³ Ocean College, Zhejiang University, Zhoushan 316021, China.
⁴ Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China. Electronic address: xuxinhua@zju.edu.cn.
⁵ School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia.

PMID: 27349842
DOI: 10.1016/j.jhazmat.2016.04.063

Abstract

Magnetic multi-walled carbon nanotubes (MWCNTs) were prepared to support Pd/Fe nanoparticles, inhibit the aggregation and passivation, and achieve magnetic separation to avoid the environmental risk of nanoparticles. Rapid adsorption of initial contaminant, steady dechlorination, and gradual desorption of final product was observed. The micromorphology, chemical structure, and components of the nanohybrids were comprehensively characterized by a series of analysis technologies, such as EDX, XRD, SEM, TEM, and XPS. The interactions between the nanohybrids compositions were discussed according to the characterization and experimental data. The whole insight of 2,4-dichlorophenol (2,4-DCP) adsorption- dechlorination-desorption was studied in detail, including the pathways, influence factors, dechlorination kinetics and selectivity. Weak acidity (pH=5.0 and 6.5) favored the 2,4-DCP removal. Satisfactory reactivity of the Pd/Fe-Fe3O4@MWCNTs nanohybrids was observed in five consecutive runs, and 99.2%, 89.6%, 92.1%, 99.8%, and 99.9% of 2,4-DCP was removed, respectively. Most of the final product (phenol) was steadily desorbed to the liquid phase, resulted in the re-exposure of active sites on the nanohybrids and maintained a longer activity.

Keywords: 2,4-Dichlorophenol; Dechlorination; Interaction; Pd/Fe-Fe(3)O(4)@MWCNTs nanohybrids; Selectivity.