Synthesis of Poly(methacrylic acid)/Montmorillonite Hydrogel Nanocomposite for Efficient Adsorption of Amoxicillin and Diclofenac from Aqueous Environment: Kinetic, Isotherm, Reusability, and Thermodynamic Investigations

Abstract

Herein, a simplistic redox polymerization strategy was utilized for the fabrication of a poly­(methacrylic acid)/montmorillonite hydrogel nanocomposite (PMA/nMMT) and probed as a sorbent for sequestration of two pharmaceutical contaminants, viz., amoxicillin (AMX) and diclofenac (DF), from wastewater. The synthesized hydrogel nanocomposite was characterized by the Fourier transform infrared, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, and transmission electron microscopy techniques to analyze structural characteristics and sorption interactions. The efficacy of PMA/nMMT was thoroughly investigated for the sequestration of AMX and DF from the aquatic phase with a variation in operative variables like agitation time, sorbent dosage, pH, and initial sorbate concentration. The reaction kinetics was essentially consistent with the pseudo-second-order model with rate dominated by the intraparticle diffusion model as well as the film diffusion mechanism. The Freundlich isotherm appropriated the equilibrium data over the entire range of concentration. Thermodynamic investigation explored the spontaneous and endothermic nature of the process. The most possible mechanism has been explained, which includes electrostatic interaction, hydrogen bonding, cationic exchange, and partition mechanism. Economic feasibility, better sorption capacity (152.65 for AMX and 152.86 mg/g for DF), and efficient regeneration and reusability even after four consecutive sorption–desorption cycles ascertained PMA/nMMT as a potential sorbent for AMX and DF uptake from the aqueous phase.

Selective Solid-Phase Extraction of Meropenem from Human Blood Plasma Using a Molecularly Imprinted Polymer

“…However, in pH 4, the adsorption was decreased because the positive charge on the MA surface was decreased. By contrast, when the meropenem met its isoelectric point of approximately 5.15 [20], it was attached to the sorbent surface by partition mechanism [21]. Further, the adsorption dropped with increasing pH because of the negative charges on both the sorbent surface and meropenem.…”

Adsorption of methyl violet dye from wastewater using poly(methacrylic acid-co-acrylamide)/bentonite nanocomposite hydrogels

“…The peaks at 1631 and 1699 cm -1 indicate the involvement of the carbonyl and vinyl groups of MAA monomer in the free radical polymerization. In addition, the peaks of 1728 and 1751 cm -1 are symmetrically bonded to carboxylate anions and C=O tensile vibrations in the monomers, respectively [28]. Figure 1c shows the FTIR spectra of poly(MAA-co-AAm)/bentonite nanocomposites after adsorption of MV dye contaminants.…”

Acrylate and Methacrylate Polymers’ Applications: Second Life with Inexpensive and Sustainable Recycling Approaches

“…In addition, a PMAA/montmorillonite (MMT) hydrogel nanocomposite (PMAA/nMMT) acted as an efficient sorbent for sequestration of pharmaceutical contaminants. Specifically, economic feasibility, better sorption capacity (152.65 for AMX and 152.86 mg/g for DF) and efficient regeneration and reusability even after four consecutive sorption−desorption cycles make PMAA/nMMT as a potential sorbent for amoxicillin and diclofenac uptake from the aqueous phase [ 92 ].…”