Assessment of copper ferrite doped montmorillonite for efficient dye removal with insights into operational parameters, adsorption pathways and regeneration capacity
摘要
Copper ferrite (CuFe2O4) nanoparticles were successfully loaded onto montmorillonite (MMT) to develop a highly active adsorptive material (MMT@CuFe2O4) capable of removing acid red 18 (AR18) and methylene blue (MB) dyes. Textural, crystalline, and morphological properties were examined by XRD, SEM, FTIR, and BET analyses. A substantial rise in surface area from 12.55 to 43.55 m²/g and an increase in total pore volume from 0.0622 to 0.1295 cm³/g in MMT@CuFe2O4 relative to MMT demonstrates the successful introduction of mesoporous structures. Adsorption data revealed that the maximum removal efficiencies of MB and AR18 were 74.23% and 88.96%, respectively, under the same conditions of time (180 min) and temperature (35 °C). The adsorption equilibrium was best described by the Langmuir model, with maximum adsorption capacities (qmax) of 17.89 mg/g for MB and 16.26 mg/g for AR18, and high correlation coefficients (R2 = 0.991 and 0.924). Kinetic data fitted the pseudo-second order model (R² > 0.97), indicating chemisorption as the dominant process, while the Elovich and intra-particle diffusion models further supported multilayer adsorption and intra-pore diffusion. The thermodynamic study demonstrated that adsorption proceeded spontaneously, as shown by the negative ΔG° values (− 3.29 to − 6.75 kJ/mol for MB and − 1.27 to − 9.01 kJ/mol for AR18), and was endothermic, with respective ΔH° values of 21.37 and 54.18 kJ/mol. Among the regeneration systems tested, electro-Fenton exhibited the highest recovery efficiency (75.63% for MB and 82.36% for AR18), whereas thermal regeneration showed the lowest (34.63% and 50.36%, respectively), demonstrating the superior regeneration performance of the EF method and the potential reusability of MMT@CuFe2O4 in practical dye removal applications.