Synthesis of 2,4-dinitrophenylhydrazine loaded sodium dodecyl sulfate-coated magnetite nanoparticles for adsorption of Hg(II) ions from an aqueous solution

Lobat Taghavi,Raziyeh Zandipak,Soheil Sobhanardakani

doi:10.15171/ehem.2016.18

Abstract

Background: The rapid increase in agricultural and industrial development has made heavy metal pollution a serious environmental problem and public health threat; therefore, removal of heavy metals from water is important. The current study prepared DNPH@SDS@Fe3O4 nanoparticles as a novel and effective adsorbent for removal of Hg(II) ions from an aqueous solution. Methods: A selective adsorbent for Hg(II) was synthesized by coating Fe3O4 nanoparticles with sodium dodecyl sulfate which was further functionalized with 2,4-dinitrophenylhydrazine (2,4-DNPH). The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscopy (SEM) and SEM–EDXSt. The effects of pH, dose of adsorbent and shaking time on adsorption capacity were investigated. The kinetics and equilibrium of adsorption of the metal ions were thoroughly studied. Results: SEM showed that the size of the nanoparticles was 20 to 35 nm. The maximum adsorption capacity for Hg(II) was 164.0 mg g-1 for an adsorbent dose of 0.04 g at pH 7.0, 25°C and the initial metal concentration was 25 mg L-1,which was greater than for most adsorbents previously examined for Hg(II) adsorption. Adsorption experimental data showed good correlation with the pseudo-secondorder model and Langmuir isotherm model. Conclusion: The results indicated that the DNPH@SDS@Fe3O4 nanoparticles are an efficient adsorbent for removal of heavy metal from wastewater. Keywords: Adsorption, Mercury, Magnetite nanoparticles, Wastewater, Kinetics

Highlights

Recent industrial activity has increased the presence of hazardous heavy metals such as mercury (Hg) ions in wastewater [1]
Adsorption, coagulation-flocculation, ion-exchange, membrane filtration, chemical precipitation, flotation and electrochemical have all been employed for metal ion removal from aqueous solution; all these methods except adsorption are inefficient for the removal of some metal ions and incur high operational costs [6,7]
2,4-dinitrophenylhydrazine (2,4-DNPH), an important reagent which can act as an electron pair donor to react with most hard and intermediate cations, was chemically immobilized on the surface of the sodium dodecyl sulfate (SDS)-coated magnetite nanoparticles and the product was used for adsorption of Hg(II) ions from an aqueous solution

Summary

Introduction

Recent industrial activity has increased the presence of hazardous heavy metals such as mercury (Hg) ions in wastewater [1]. Adsorption has been demonstrated to be the most efficient method for removal of heavy metal ions from aqueous solutions [8,9]. 2,4-dinitrophenylhydrazine (2,4-DNPH), an important reagent which can act as an electron pair donor to react with most hard and intermediate cations, was chemically immobilized on the surface of the SDS-coated magnetite nanoparticles and the product was used for adsorption of Hg(II) ions from an aqueous solution. The current study prepared DNPH@SDS@Fe3O4 nanoparticles as a novel and effective adsorbent for removal of Hg(II) ions from an aqueous solution. Conclusion: The results indicated that the DNPH@SDS@Fe3O4 nanoparticles are an efficient adsorbent for removal of heavy metal from wastewater. Synthesis of 2,4-dinitrophenylhydrazine loaded sodium dodecyl sulfate-coated magnetite nanoparticles for adsorption of Hg(II) ions from an aqueous solution.

Methods

Results

Discussion

Conclusion