Selective sorption of Pb(II) from aqueous solution using an imprinted silica-supported sorbent based on the solgel imprinting technique

Abstract

A lead ion-imprinted silica-supported sorbent (LIS) was prepared by the solgel method with lead ions as the template. The structural characteristics of the LIS were determined using Fourier transform infrared spectrometry and measurements of specific surface area. The selective adsorption performance of the LIS for the removal of Pb(II) from an aqueous solution was investigated in batch-type experiments. The adsorbent capacity and selectivity of the LIS were greater than those of the tested non-imprinted sorbent (NIS). The selectivity coefficients (α(K_di/K_dj)) of the LIS for Pb(II)/Cd(II) and Pb(II)/Ni(II) were 16.98 and 37.71, respectively, while those of NIS were only 3.53 and 3.29, respectively. Adsorption of Pb(II) by the LIS was well fitted by pseudo-second-order kinetic and Langmuir models. In addition, the thermodynamic parameters showed that Pb(II) adsorption onto the imprinted silica-supported LIS was an endothermic, positively entropic, and spontaneous sorption process.

Keywords:

• Selective adsorption
• Pb(II)
• Imprinted silica-supported sorbent
• Thermodynamics
• Kinetic model

Acknowledgments

This work was supported by the Scientific Research Award Foundation for Shandong Provincial (ZR2014EMQ007), the Science and Technology Development Program of Binzhou (2013ZC0702).