Water Practice and Technology (May 2024)
Characterization and applicability of the Naima–Tiaret–Algeria illite-montmorillonite clay for methylene blue dye removal: adsorption kinetic, isotherm and thermodynamic studies
Abstract
An illite-montmorillonite clay from Naima, IMN (Algeria) was treated via physical and chemical treatment (TIMN) and investigated for the removal of methylene blue. IMN and TIMN clays were characterized by XRD, XRF, SEM-EDS, DSC-TG, FTIR and DC electrical conductivity methods. To analyze the sorption behavior of MB on the clays, a mechanistic model for interpreting the sorption data was developed. IMN clay revealed high sorption capacity (1.925 × 10−2 kg kg−1) for MB in 60 min. The pseudo-second-order model had a very good agreement to describe the MB adsorption process. The adsorption capacities, qe,exp, of 4.327 × 10−2 and 4.914 × 10−2 kg kg−1 for IMN and TIMN, respectively, were obtained. The free energy from the D–R model from adsorbing MB using IMN and TIMN ranged from 1.581 to 0.745 × 10−3J mol−1, respectively, suggesting that the process is physisorption. Besides, the sorption process was more sensible to temperatures that increase was beyond 40 °C causing a decrease in adsorption capacity, indicating that the adsorption reaction of MB onto IMN was exothermic. The adsorption mechanism of I/M clay to remove MB was likely based on hydrogen bonding, electrostatic attraction, cation exchange and n–π interaction. These results proved that TIMN was a promising adsorbent for removing MB from simulated wastewater. HIGHLIGHTS Natural Illite-Montmorillonite clay from Naima (IMN) and its modified form (TIMN) were successfully elaborated via physical and chemical treatments.; IMN and TIMN clays were characterized by X-ray diffraction (XRD), X-Ray Fluorescence (XRF), Fourier Transformed Infrared (FTIR), DC electrical conductivity, Scanning Electron Microscopy Energy Dispersive X-ray Spectroscopy (SEM-EDS), and DSC-TG methods.; IMN and TIMN clays were explored for the removal of methylene blue (MB) dye.; Up to 90 % removal of MB was achieved within 60 min by IMN and TIMN clays.; The driving factors of the adsorption process were categorized as hydrogen bonding, electrostatic attraction, cation exchange, n-π and OH−π interactions.;
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