Response surface methodology for the high efficiency removal of lead and zinc from effluents using natural sepiolite particles on the corn silk

ABSTRACT

The purpose of this research was the synthesis of corn silk/sepiolite (CS/SEP) for the elimination of lead and zinc from industrial effluents. The properties of the composite were studied using BET, FT-IR, FESEM, and XRD techniques. Effects of amount of adsorbent, pH, initial concentration, and contact time on lead and zinc heavy metal ions adsorption were studied by central composite design (CCD). The results showed that the highest removal efficiency of lead and zinc (93.13% and 89.04%, respectively) was obtained at pH = 5.49, adsorbent amount: 0.03 g, and contact time: 19.92 min. Besides, the equilibrium and kinetic studies showed that the Langmuir isotherm model (q_max: 245.71 and 199.47 mg g⁻¹ for copper and zinc, respectively) and the pseudo-second-order kinetic model could better determine the sorption process of lead and zinc by the corn silk/sepiolite composite than other models. Also, the thermodynamic study indicated that the sorption process was endothermic.

KEYWORDS:

• Lead
• zinc
• removal
• sepiolite
• corn silk
• central composite design

Acknowledgments

We gratefully acknowledge the financial assistance provided by the Omidiyeh Branch of Islamic Azad University.

Disclosure statement

No potential conflict of interest was reported by the author(s).