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

Chitosan-integrated TiO₂ nanocomposite for adsorptive removal of Cd and Pb from drinking water

Suraya Samejo, Jameel Ahmed Baig, Tasneem Gul Kazi, Hassan Imran Afridi, H. Elhosiny Ali, Saima Perveen, Khalil Akhtar, Shakoor Ahmed Solangi, Fahad Abbasi, and Sajjad Hussain

Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan

E-mail: jameel.baig@usindh.edu.pk

Received: 21 October 2023  Accepted: 23 July 2024

Abstract:

This work described a plant extract-based synthesis of titanium oxide nanoparticles (D-TiO₂–NPs) using Duranta erecta leave extract, followed by the fabrication of its nanocomposite (D-TiO₂–NC) with chitosan for adsorptive removal of toxic metals (TMs) cadmium (Cd) and lead (Pb) from water. D-TiO₂–NPs and D-TiO₂–NC were characterized by various analytical techniques. This study confirmed the porous and rough crystalline nanostructure with different functional groups of chitosan and D-TiO₂–NPs of synthesized D-TiO₂–NC for feasible excellent adsorptive removal of Cd and Pb. The maximum removal of Cd and Pb was achieved at pH (6), initial concentration of metal ions (30 mg L⁻¹), the content of D-TiO₂–NC (50 mg), contact time (30 min), and temperature (45 °C) with adsorption capacities of 147 and 145.5 mg g⁻¹, respectively. The D-TiO₂–NC has successfully followed the pseudo-second-order kinetics for the successful removal of Cd and Pb. However, the resulting data followed multilayer adsorption for the removal of Cd while monolayer adsorption for Pb onto the D-TiO₂–NC. The findings of the thermodynamic study revealed that the D-TiO₂–NC followed the endothermic and spontaneous adsorption process for the adsorption of Cd and Pb. Furthermore, D-TiO₂–NC can easily be used several times after washing with diluted HNO₃ for the adsorptive removal of Cd and Pb. Moreover, it is quantitatively adsorbed (> 90%) the Cd and Pb from the collected drinking water samples.

Graphical abstract

Keywords: Environmental Chemistry; Chitosan; D-TiO2–NC; Pb and Cd; Adsorption; Isotherm model; Kinetics model; Thermodynamic study

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03637-6

Chemical Papers 78 (14) 7827–7843 (2024)