Statistically optimised sequestration of mefenamic acid from polluted water by acacia gum phthalate/pectin hydrogel: A novel multifunctional adsorbent material synthesised via microwave-assisted process

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-06, Vol.466, p.143296, Article 143296
• Main Authors: Abbasi, Neha, Khan, Suhail Ayoub, Khan, Tabrez Alam
• Format: Article
• Language: English
• Subjects: Acacia gum phthalate; Adsorption; Hydrogel; Mefenamic acid; Pectin; Response surface methodology
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143296

[Display omitted] •A novel multifunctional hydrogel (AGP/PEC) was prepared by microwave-assisted method.•Mefenamic acid (MFA) removal was optimised via central composite design in RSM.•Langmuir isotherm and PSO kinetic models appropriately described the equilibrium data.•The AGP/PEC exhibited high removal efficiency of 93.45% and Qm of 103.43 mg MFA/g.•H-bonding, electrostatic, π − π and n − π interactions majorly governed the MFA uptake. Pharmaceuticals and personal care products (PPCPs) are an emerging class of perilous pollutants due to their potential inimicalimpacts on ecosystems necessitating their abatement.Herein, an environmentally-affable and multifunctional acacia gum phthalate/ pectin hydrogel (AGP/PEC) was innovatively synthesised by microwave-assisted free-radical polymerisation for subsequent mefenamic acid (MFA) decontamination from synthetic wastewater. The physicochemical characteristics of AGP/PEC was studied through FTIR, XRD, BET, TEM, SEM-EDX and XPS characterisation techniques showing the existence of –OH and –COOH functionalities, rough surface with good surface area (18.95 m2/g) and porosity that contributed to high MFA uptake (93.45%) via hydrogen-bonding, electrostatic, pore-filling, π−π, and n−π interactions. The independent and interactive influences of operative variables on the adsorption capacity of AGP/PEC was statistically evaluated via central composite design of response surface methodology. The most-effective MFA uptake was attained at optimal operating conditions: initial solution pH (5.9), dosage (0.4 g/L), and time (28.5 min). Langmuir isotherm with Qm = 103.43 mg MFA/g and pseudo-second order kinetic models best-correlated the corresponding data. The Qm increased with temperature specifying an endothermic process, which was authenticated by positive ΔH⁰ (= 7.75 kJ/mol). The parameter, bT = 0.16 kJ/mol and ED = 2.12 kJ/mol, calculated from Temkin and Dubinin−Radushkevich isotherm models, respectively specified physisorption. The better adsorptive competence in real water along with an excellent reusable potential (87.1%) up to fifth cycle designated AGP/PEC as a potent adsorbent for practical purposes. These findings accentuated that AGP/PEC could be gainfully implemented as green and advanced multifunctional adsorbent material for removing residual MFA from wastewater.