Acid-Modified and Surfactant-Functionalized Bentonite and Clinoptilolite for Naproxen Adsorption from Water
4 affiliations
- 1Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza 66450, NL, Mexico
- 2Tecnologico de Monterrey, Instituto de Materiales Avanzados para la Manufactura Sostenible, Av. Eugenio Garza Sada 2501, Monterrey 64849, NL, Mexico
- 3Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Ave. Eugenio Garza Sada 2501 Sur, Monterrey 64700, NL, Mexico
- 4Ingeniería en Diseño Industrial, Universidad Politécnica de Apodaca, Av. Politécnica No. 2331, Col. El Barretal, Apodaca 66600, NL, Mexico
Abstract
Pharmaceutical contamination of aquatic environments, particularly by nonsteroidal anti-inflammatory drugs such as naproxen, remains a persistent challenge for conventional water treatment. This study evaluated the naproxen adsorption performance of bentonite and clinoptilolite in their natural, acid-activated, and hexadecyltrimethylammonium (HDTMA)-modified forms. Materials were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen physisorption, confirming that acid activation increased surface area and porosity while HDTMA introduced an organophilic character without disrupting the crystalline framework. Adsorption experiments identified pH 6 as optimal for all HDTMA-modified materials. Sequentially modified clinoptilolite (C-AS) achieved the highest capacity, reaching 14.8, 16.5, and 19.9 mg g−1 at 25, 30, and 35 °C, respectively, outperforming all bentonite-based materials, whose interlayer pore blockage limited surfactant benefits. Kinetic data were best described by the pseudo-second-order model for most materials, while the Elovich and Avrami fractional-order models provided superior fits overall, with sub-unitary Avrami exponents indicating a heterogeneous, multi-pathway adsorption mechanism; Weber–Morris analysis further confirmed that intraparticle diffusion was not the sole rate-limiting step. Equilibrium data showed mixed Langmuir–Freundlich behavior that was resolved using the Sips model, and thermodynamic parameters derived from a three-temperature (25–35 °C) study confirmed spontaneous, endothermic adsorption governed by physisorption. These results demonstrate that the pairing of acid activation with surfactant functionalization is markedly more effective for zeolitic frameworks than for layered clays, offering a low-cost strategy for pharmaceutical removal from water.
Related
- CTAB-functionalized clinoptilolite alginate microbeads for enhanced Congo Red adsorption: performance, kinetics and equilibrium analysis
- Valorization of Rice Husk through the Development of New Materials of Silica Functionalized with Phthaloyl Diamide Ligands: Characterization, Isomer Effect, Ag+ Adsorption Investigation, and Antibacterial Activity
- Artificial neural network-assisted modelling of methylene blue dye adsorption onto ZIF-8 functionalized fishtail palm seed biomass: Isotherm and performance analysis
- Preparation of Customizable Ligand-Functionalized Chitin Biopolymer Adsorbents Utilizing the Azide–Alkyne “Click” Reaction for the Adsorption of Aqueous Cu(II)
- Development of hybrid amine-functionalized diatom-based materials for efficient formaldehyde adsorption under dry and humid conditions
BibTeX
@article{rivera2026acidmodified,
title = {{Acid-Modified and Surfactant-Functionalized Bentonite and Clinoptilolite for Naproxen Adsorption from Water}},
author = {Gloria Lourdes Dimas Rivera and Mario Osvaldo Caballero Leal and Teresa de Jesús Montalvo Herrera and Ladislao Sandoval Rangel and David Alejandro De Haro Del Río},
journal = {Molecules},
year = {2026},
month = oct,
doi = {10.3390/molecules31203636},
url = {https://www.mdpi.com/1420-3049/31/20/3636},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Acid-Modified and Surfactant-Functionalized Bentonite and Clinoptilolite for Naproxen Adsorption from Water
AU - Gloria Lourdes Dimas Rivera
AU - Mario Osvaldo Caballero Leal
AU - Teresa de Jesús Montalvo Herrera
AU - Ladislao Sandoval Rangel
AU - David Alejandro De Haro Del Río
PY - 2026
DA - 2026/10/01
JO - Molecules
DO - 10.3390/molecules31203636
UR - https://www.mdpi.com/1420-3049/31/20/3636
AB - Pharmaceutical contamination of aquatic environments, particularly by nonsteroidal anti-inflammatory drugs such as naproxen, remains a persistent challenge for conventional water treatment. This study evaluated the naproxen adsorption performance of bentonite and clinoptilolite in their natural, acid-activated, and hexadecyltrimethylammonium (HDTMA)-modified forms. Materials were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen physisorption, confirming that acid activation increased surface area and porosity while HDTMA introduced an organophilic character without disrupting the crystalline framework. Adsorption experiments identified pH 6 as optimal for all HDTMA-modified materials. Sequentially modified clinoptilolite (C-AS) achieved the highest capacity, reaching 14.8, 16.5, and 19.9 mg g−1 at 25, 30, and 35 °C, respectively, outperforming all bentonite-based materials, whose interlayer pore blockage limited surfactant benefits. Kinetic data were best described by the pseudo-second-order model for most materials, while the Elovich and Avrami fractional-order models provided superior fits overall, with sub-unitary Avrami exponents indicating a heterogeneous, multi-pathway adsorption mechanism; Weber–Morris analysis further confirmed that intraparticle diffusion was not the sole rate-limiting step. Equilibrium data showed mixed Langmuir–Freundlich behavior that was resolved using the Sips model, and thermodynamic parameters derived from a three-temperature (25–35 °C) study confirmed spontaneous, endothermic adsorption governed by physisorption. These results demonstrate that the pairing of acid activation with surfactant functionalization is markedly more effective for zeolitic frameworks than for layered clays, offering a low-cost strategy for pharmaceutical removal from water.
SN - 1420-3049
ER -