Study on adsorption of Cd2+ by Ti‐pillared montmorillonite‐mixed activated carbon

Abstract

Abstract In this study, the composite of Ti‐pillared montmorillonite‐mixed activated carbon (TPM‐AC) was prepared by the water immersion method, and the adsorption of Cd2+ was studied under static conditions. A series of single experiments were conducted to determine the effects of the solution pH, adsorption time, initial Cd2+ concentration, and solution temperature on adsorption performance. The adsorption kinetics, isotherms, and thermodynamics behaviours of Cd2+ onto TPM‐AC were investigated. The results showed that the Brunauer–Emmett–Teller specific surface area and pore volume of TPM‐AC are increased, the crystallinity is greatly improved, and porous structural material with a large specific surface area is formed. The adsorption of Cd2+ by TPM‐AC is excellent and better than that of AC and TPM. The adsorption of Cd2+ by TPM‐AC, AC, and TPM can be described by the pseudo‐second‐order kinetic equation, and the adsorption isotherm is more consistent with the Langmuir isotherm model. The RL values of the dimensionless separation constants are all between 0 and 1, indicating that adsorption of Cd2+ is a relatively easy adsorption process. The values of thermodynamic parameters indicated that the adsorption is a reverse spontaneous and endothermic process.

Keywords

• Water (environmental science)
• Environmental issues
• Engineering materials