Synthesis and characterization of activated carbon from sugar beet residue for the adsorption of hexavalent chromium in aqueous solutions.

Jiaming Zhao,Huixia Ma,Guang Wu,Feng Zhou,Lihua Yu,Kongyan Yang

doi:10.1039/d0ra09644j

Abstract

A series of micro–mesoporous activated carbons (ACs) were prepared from sugar beet residue by a two-step method including KOH chemical activation and were used for Cr(vi) removal from aqueous solutions. Several characterization techniques, including SEM, TEM, N2 adsorption, XRD, FTIR, and Raman spectroscopy, were used to determine the chemical and physical characteristics of the ACs, and the adsorption properties of the ACs were tested. The results indicated that the high specific surface area of the ACs reached 2002.9 m2 g−1, and the micropore surface area accounts for 85% of the total area. The optimal conditions for achieving the maximum Cr(vi) adsorption capacity of 163.7 mg g−1 by the ACs were activation with a KOH/carbon ratio of 3.0, an initial Cr(vi) concentration of 400 mg L−1, an adsorbent dose of 2.0 g L−1 and pH of 4.5. Therefore, the ACs exhibit excellent adsorption performance for removing Cr(vi) from aqueous solutions. According to an investigation of the adsorption process, the adsorption isotherm is most consistent with the Langmuir isotherm model, and the adsorption kinetics were well described by the pseudo-second-order model.

Highlights

Chromium is a common metal pollutant mainly originating from industrial wastewater from electroplating, metallurgy, tanning, printing and dyeing processes.[1]
scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the morphologies of the beet residue and activated carbons (ACs) are shown in Fig. 1 and 2
The results indicate that the adsorption process of Cr(VI) by AC-3.0-700 can be described properly by the pseudo-second-order model, because the R2 value is the highest and the calculated adsorption capacity is comparatively similar to the practical experimental adsorption capacity

Summary

Introduction

Chromium is a common metal pollutant mainly originating from industrial wastewater from electroplating, metallurgy, tanning, printing and dyeing processes.[1]. The removal of Cr(VI) from contaminated water is important for protecting the environment and human health

Methods

Results

Conclusion