فهرست نشریات علمی دسترسی آزاد ایران

Herein, the synthesis of a novel eco-friendly hydrogel composite was carried out using sodium carboxymethyl cellulose (SCMC) and methacrylic acid (MAA) as major monomers to produce free radical polymerization combined with modified bentonite. Both PMAA added functional groups and increased the density of functional groups on the surface for more efficient reaction kinetics with AAP, while sodium-modified bentonite also significantly improved BET surface area, cation-exchange capacity (CEC), and structural integrity – all contributing to a clearly defined porous structure containing abundant active sites. FTIR, XRD, BET, FE-SEM and TGA were used to characterize the composite and confirm its structural, chemical and morphological properties. The influence of varying adsorbent dosage, contact time, solution pH and temperature were evaluated through batch adsorption tests for its removal on the crystal violet (CV) dye. Through optimization of parameters such as pH (pH = 8) and equilibrium time (t = 72 h), a maximum adsorption capacity of the hydrogel was reached, equal to 140.56 mg·g⁻¹, whereas the optimal removal efficiencies towards toxic metals were computed at T = 5°C. Results obtained from adsorption data fitted the Langmuir isotherm and suggested monolayer chemisorption on a homogenous surface. Thermodynamic calculation indicated ΔS° = −9.108 J·mol⁻¹·K⁻¹, ΔG° = +2.523 kJ·mol⁻¹ and ΔH° = −10.485 kJ·mol⁻¹ that presented the moderate spontaneity and exothermic reaction stage during the crystallization process. The PMAA/SCMC/modified bentonite hydrogel shows a good structural property and an exceptional adsorption stability for CV dye, as proved by above mentioned findings. In summary, this composite exhibited a potential clean adsorbent for high performance wastewater treatment.