Adsorption properties of Pb²⁺ on thermal-activated serpentine

ABSTRACT

Adsorption properties of nature and thermal-activated serpentines to Pb²⁺ in aqueous solution were investigated. The results showed that Freundlich isotherm and pseudo-second-order kinetics model were suitable to describe the adsorption process of Pb²⁺ on serpentines. The thermodynamic parameters indicated that the adsorption process was endothermic and spontaneous. The serpentine activated at 700°C exhibited maximum adsorption capacity to Pb²⁺. Based on the XRD and XPS characterization, it could be found that the structure of serpentine did not change significantly during the adsorption process, and Pb²⁺ was adsorbed on the serpentine surface as the precipitation of Pb(OH)Cl and Pb(OH)₂.

KEYWORDS:

• Serpentine
• thermal activation
• Pb²⁺
• heavy metal
• adsorption

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 21707009, 21406016), the Doctor Startup Research Foundation of Liaoning Province (No. 20180540007), the Natural Science Foundation of Liaoning Province (No. 2015020201), the Program for Liaoning Excellent Talents in University (No. LJQ2015002).