ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of ionic liquid to highly selective removal of Cd²⁺ onto carbon nanotube: optimized by Plackett–Burman design method

Mina Dana, Parastoo Jamshidi, and Farzaneh Shemirani

School of Chemistry, College of Science, University of Tehran, Tehran, Iran

E-mail: mina.dana@ut.ac.ir

Received: 7 November 2022  Accepted: 20 August 2023

Abstract:

This article investigates the effect of adding HMIMBF₄ (HM) to remove high amount of Cd²⁺ ions. Magnetic carbon nanotube (mCNT) was used as the main part of the adsorbent, and a Schiff base kind of N,N′-bis(salicylidene)ethylenediamine (ES) was applied to increase the selectivity of the method toward Cd²⁺ ions. X-ray diffraction patterns, Fourier-transform spectra, scanning electron microscopy pictures and alternative gradient force magnetometry characterize and confirm the interaction among the components, the presence of the materials, successful modification procedure and enough magnetic property. To better compare the adsorption applicability of HM, ES-mCNT and ES-HM-mCNT, the preconcentration condition was optimized for each adsorbent by the Plackett–Burman Design method. The swelling property confirms more affinity of ES-HM-mCNT toward Cd²⁺ ions, because it improved the dispersibility of the adsorbent into the sample solution. The reusability was 18 and 11 times for ES-mCNT and ES-HM-mCNT, respectively. Both adsorbents were durable for 60 days. Both systems follow the Langmuir isotherm adsorption model and the Pseudo-Second order kinetic model. Thermodynamic adsorption investigation shows that the adsorption in both systems is endothermic and spontaneous.

Keywords: Ionic liquid; Schiff base; Cd2+; Removal; Flame atomic adsorption; Magnetic separation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03044-3

Chemical Papers 78 (1) 141–150 (2024)