Applicability of mesoporous carbon-glassy polyvinyl alcohol/silica gel hybrid composite to remove methylene blue from aqueous solution

Methylene blue removal from aquatic environment using newly synthesized mesoporous carbon-glassy polyvinyl alcohol/silica gel composite. The mesoporous hybrid composite was characterized using several techniques, including IR, UV–Visible, TGA, surface morphological analyses images, EDX spectra and XRD. The removal method of methylene blue removal affected by factors such as increase in pH, temperature, time of adsorption, MB initial concentration and dosage of adsorbent was investigated. The elimination percentage of MB varied from 91 to 96% as the temperature increased from 293 to 323 K, respectively. The efficiency of MCPS is evident by giving a 91% removal rate for a 25 mg/L dye solution at 293 K compared to 44% for the glassy PVA/silica gel hybrid composite and 36% for mesoporous. The desorption efficiencies obtained for MCPS were 8%, 32% and 6.5% for H₂O, HCl and acetic acid, respectively. The findings were processed utilizing two adsorption isotherm models in addition to kinetic models. The kinetic analysis results suggested that the pseudo-first-order model was consistent with the experimental findings. The Langmuir isotherm model was considered to be an adequate model for the uptake process. The highest capacities for uptake at 293, 303, 313 and 323 K were 13.55, 16.59, 19.81 and 25.01 mg/g, respectively. The thermodynamic parameters explained that MB removal was spontaneous and endothermic with ΔH ^o = 26.24 kJ/mol. From the low desorption efficiencies, we confirmed the uptake of MB by MCPS via physisorption.