Sodium hydroxide supported cellulose for efficient removal of cationic dyes from aquatic solutions in batch and column modes: Adsorption characteristics and mechanism study

In the present study, sodium hydroxide-modified cellulose powder (SCP) adsorbent is prepared from cellulose powder (CP). The prepared sorbents are characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Brunauer, Emmett, and Teller (BET) and N2 adsorption isotherm, energy-dispersive X-ray spectroscopy (EDX), Xray diffraction (XRD), Thermogravimetric analysis (TGA), and point of zero charge. The batch adsorption method is applied to determine the optimum operational parameters for the removal of MB (MB) from aqueous solutions, including the initial concentration of dye, pH, adsorbent dosage, and contact time. Various kinetic models have been applied to test the experimental data to determine the mechanism of adsorption and its potential rate-controlling step. The obtained kinetics data revealed that the adsorption process of the dye is more fitting to the pseudo-second order than the pseudo-first order. Equilibrium data showed that the adsorption of the dye fits well with the Langmuir equilibrium isotherm model with maximum adsorption capacities of . Thermodynamic parameters, 0G degrees, 0H degrees, and 0S degrees, have been investigated. The negative values of 0G degrees for all sorbents explain the spontaneous behavior of the adsorption process, while the negative values of 0H degrees can explain the exothermic ic behavior of all sorbents. The prepared cellulose adsorbents were successfully applied for the removal of MB dye at low concentrations from different water samples.