Optimization and modeling of Pb ions adsorption on bentonite and HNO-activated bentonite using Taguchi and ANOVA methods

This study investigates the activation of bentonite using HNO 3 and its application for Pb 2+ adsorption. Physical-chemical analyses (Brunauer–Emmett–Teller, X-ray diffraction, and Fourier transform infrared) revealed that HNO 3 activation enhanced the surface area and altered the structural charact...

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Bibliographic Details
Main Authors: Nguyen Xuan Loc, Nguyen Thi Anh Thu, Do Thi My Phuong
Format: Article
Language:English
Published: SAGE Publishing 2025-05-01
Series:Adsorption Science & Technology
Online Access:https://doi.org/10.1177/02636174251338370
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Summary:This study investigates the activation of bentonite using HNO 3 and its application for Pb 2+ adsorption. Physical-chemical analyses (Brunauer–Emmett–Teller, X-ray diffraction, and Fourier transform infrared) revealed that HNO 3 activation enhanced the surface area and altered the structural characteristics of bentonite. Adsorption experiments, designed using the Taguchi method (L25, four factors, five levels), identified contact time as the most influential factor for Pb 2+ removal. The maximum Pb 2+ adsorption capacity of HNO 3 -activated bentonite was 1.3 times higher than raw bentonite (61.77 mg/g vs 48.22 mg/g). Adsorption isotherms fitted well with the Temkin model (R 2  > 0.9, χ 2  < 0.15), and kinetic data followed the Elovich model (R 2  > 0.91, χ 2  < 1.44). The initial sorption rate (α) for HNO 3 -activated bentonite was 1.12 times greater than that of bentonite, indicating enhanced adsorption kinetics. This study demonstrates the effectiveness of HNO 3 -activated bentonite for efficient Pb 2+ removal from aqueous solutions.
ISSN:2048-4038