Removal of Cd(II) ions from aqueous solutions by nanodiopside as a novel and green adsorbent: Optimisation by response surface methodology

ABSTRACT

In this research, adsorption removal of cadmium ions from aqueous solutions by nanodiopside as a novel, green, and efficient adsorbent was studied. The prepared nanodiopside was characterised by FESEM, FTIR, XRD, EDX, TEM and BET analyses. All of the analyses indicated that the nanodiopside was synthesised correctly. The effect of several parameters on the removal percentage of the copper was investigated by central composite design and the optimal condition of parameters for maximum Cd²⁺ adsorption process was as follows: pH = 5.60, adsorbent dosage: 0.13 mg, Cd²⁺ concentration: 23.16 mg L⁻¹, contact time: 43.83 min, and temperature: 34.75 ^◦C, respectively. The kinetic and equilibrium data were explained by Pseudo-second-order (R²: 0.999) and Freundlich models (q_max: 124.92 mg g⁻¹ and R²: 0.998), respectively. The results of the reusability of nanodiopside after six sorption desorption cycles provide a promising potential for future industrial activities.

KEYWORDS:

• Nanodiopside
• adsorption
• removal
• cadmium (II)
• central composite design

Acknowledgments

Supports from Payame Noor University in Isfahan Research Council and contribution from Shahrekord University.

Disclosure statement

No potential conflict of interest was reported by the authors.