Kinetic and Thermodynamic Studies of Zn²⁺ Adsorption Onto Superparamagnetic Poly (styrene-co-acrylic acid) Hydrogel

Abstract

The present research focuses on removal efficiency of superparamagnetic nano iron oxide loaded poly (styrene-co-acrylic acid) hydrogel for Zn²⁺ ions from aqueous solution by batch adsorption technique. The influence of pH, contact time, adsorbent dose, temperature, and metal ion concentration on the sensitivity of the removal process was inspected. Out of various kinetic models proposed, the pseudo second order seems to fit in the experimental data in the best way. Different thermodynamic parameters ΔG⁰, ΔH⁰, and ΔS⁰ have also been evaluated. The maximum percentage removal of Zn²⁺ ions (95%) was obtained at pH 7 in 120 min at room temperature (25°C).

Keywords:

• superparamagnetic nano iron oxide
• hydrogel
• isotherms
• kinetics
• thermodynamics

Acknowledgments

The authors are also grateful to UGC-DAE Consortium for Scientific Research, Indore, India, for XRD, FTIR, and AFM analysis and AIIMS, New Delhi, India, for TEM analysis.

Funding

The authors would like to express thanks to the Department of Atomic Energy, BRNS-BARC, Mumbai, India, for providing financial assistance.