Removal of Cr(VI) and Hg(II) ions from wastewater by novel β-CD/MGO-SO3H composite

Abstract A novel magnetic adsorbent β -CD/MGO-SO 3 H with excellent hydrophilicity and high adsorption capacity was developed for removal of Cr(VI) and Hg(II) ions from wastewater. The adsorbent was characterized by transmission electron microscopy, X-ray diffraction and vibrating sample magnetometer. The kinetic adsorption test showed that the adsorptions of Cr(VI) and Hg(II) ions on the adsorbent fitted well with the pseudo-second order kinetics. The adsorption isotherms indicated that the adsorptions of Hg(II) and Cr(II) followed the Langmuir and the Freundlich models in single metal ion systems, respectively, while in binary metal ion systems they all followed the Langmuir model. The thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. Results showed that the as-prepared β -CD/MGO-SO 3 H composite could be utilized as an efficient and magnetically separable adsorbent for Cr(II) and Hg(II) in wastewater.