Chemically modified rice husk as an effective adsorbent for removal of palladium ions

Kareem A Nabieh; Wael I Mortada; Tamer E Helmy; Ibrahim M M Kenawy; Yasmeen G Abou El-Reash

doi:10.1016/j.heliyon.2021.e06062

Chemically modified rice husk as an effective adsorbent for removal of palladium ions

Heliyon. 2021 Jan 22;7(1):e06062. doi: 10.1016/j.heliyon.2021.e06062. eCollection 2021 Jan.

Authors

Kareem A Nabieh¹, Wael I Mortada¹, Tamer E Helmy¹, Ibrahim M M Kenawy², Yasmeen G Abou El-Reash²

Affiliations

¹ Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt.
² Chemistry Department, Faculty of Science, Mansoura University, Mansoura 35516, Egypt.

Abstract

Bio-matrix of rice husk and Mobil Composition of Matter No. 41 (MCM-41) was modified with alizarin red S for preconcentration of Pd²⁺ prior flame atomic absorption spectrometric determination. The prepared bio-matrix (RH@MCM-41@ARS) was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope, energy dispersive X-ray spectrometer (SEM/EDX) and surface area studies. The impact of different parameters (solution pH, amount of sorbent, contact time, sample volume, initial Pd²⁺ concentration and diverse ions) on the uptake of Pd²⁺ were evaluated. The maximum adsorption capacity of Pd²⁺ onto RH@MCM-41@ARS was 198.2 mg g^-1 at optimum conditions. Applying the optimized procedure as a preconcentration step led to limit of detection of 0.13 μg L^-1 and dynamic analytical range up to 500 μg L^-1. The sorbent was regenerated by 0.5 mol L^-1 thiourea for at least 10 cycles without significant reduction of adsorption capacity. The method was applied for preconcentration of Pd²⁺ from real samples.

Keywords: Modified rice husk; Palladium; Preconcentration.