Kinetics, isotherms and thermodynamic modeling of Mn²⁺ and Zn²⁺ single and binary removal using mercapto functionalized silica aerogel

Abstract

Heavy metals pollution is one of today's concerns of human societies. In the present project, mercapto functionalized silica aerogel was used to remove Zn²⁺ and Mn²⁺ from aqueous solution. The simultaneous adsorption of these ions has also studied. The kinetics and thermodynamics of the adsorption process as well as various isotherm models have been investigated. The results show that the adsorption process is spontaneous and favorable. The adsorption followed the Langmuir model and the maximum adsorption capacity for manganese and zinc was 1.38 and 1.33 mmol/lit, respectively. The kinetics of the adsorption process corresponds to the pseudo-second order equation. Intra particle diffusion model illustrated a greater affinity to the zinc ion, which confirmed by simultaneous adsorption results.

Graphical Abstract

Keywords:

• Binary adsorption
• isotherms
• kinetics
• silica aerogel
• thermodynamics