Removal of Chromium(VI) by Chitosan Beads Modified with Sodium Dodecyl Sulfate (SDS)

Xiaoyu Du,Naoki Kano,Chihiro Kishima,Haixin Zhang,Naoto Miyamoto

doi:10.3390/app10144745

Abstract

In this study, chitosan beads modified with sodium dodecyl sulfate (SDS) were successfully synthesized and employed for the removal of chromium(VI) (Cr(VI)). The adsorption performance of the adsorbent (SDS-chitosan beads) was examined by batch experiments. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The adsorbent (SDS-chitosan beads) showed a maximum Cr(VI) adsorption capacity of 3.23 mg·g−1 and PC of 9.5 mg·g−1·mM−1 for Cr(VI). The prepared adsorbent was characterized by different techniques such as scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared spectroscopy (FT-IR). We used inductively coupled plasma mass spectrometry (ICP-MS) for the determination of Cr(VI) in solution. The experimental data could be well-fitted by pseudo-second-order kinetic and Langmuir isotherm models. The thermodynamic studies indicated that the adsorption process was favorable under the higher temperature condition. The SDS-modified chitosan beads synthesized in this work represent a promising adsorbent for removing Cr(VI).

Highlights

Toxic metal contamination in aquatic environments has attracted tremendous attention due to the rapidly increasing number of manufacturing industries
We evaluated the adsorption of chitosan modified with sodium dodecyl sulfate (SDS)
The maximum removal of Cr(VI) by modified chitosan beads can be obtained by controlling the SDS concentration

Summary

Introduction

Toxic metal contamination in aquatic environments has attracted tremendous attention due to the rapidly increasing number of manufacturing industries. Cr has been widely applied in many industrial activities based on its excellent properties, for example, such as in electroplating, leather tanning, nuclear power plants, and textile industries [3,4] It can be used for anodizing, corrosion control, and chemical manufacturing [5,6,7]. In a natural aqueous environment, Cr(VI) may exist in the form of CrO4 2− or HCrO4 − , whereas Cr(III) is inclined to form [Cr(H2 O)6 ]3+ , Cr(H2 O) (OH)2+ , Cr(H2 O) (OH)2 + , or Cr(III) organic complexes It is well-known that Cr(III) is an essential material for organisms, whereas Cr(VI) is more toxic, carcinogenic, and mutagenic [8,9].

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