Abstract
Cellulose fibers/Zeolite-A composite (CF/ZA) was synthesized as an innovative hybrid structure of enhanced adsorption properties for different selenium species (inorganic (selenate (Se VI)), selenite (Se (IV)), and organic (selenomethionine (SeMt)). The CF/ZA composite achieved actual adsorption capacities of 163 mg/g (Se (VI)), 212.4 mg/g (Se (IV)), and 109.3 mg/g (SeMt) which are higher values than zeolite, cellulose, and several studied adsorbents in literature. The kinetic and classic equilibrium studies are in agreement with Pseudo-First order kinetics (R-2 > 0.95) and Langmuir isotherm (R-2 > 0.89). This suggests homogenous, monolayer, and more physical uptake of the three selenium species. The monolayer model of one energy was assessed as an advanced equilibrium model. Based on the steric n parameter (2.88-3.31(Se (VI), 2.22-5.94 (Se (IV), and 3.46-4.41 (SeMt)) demonstrate the adsorption of them as three or more ions per each site in a vertical orientation by multi-ionic mechanisms. The adsorption energies (-20.78 to -27.14 kJ/mol) are related to physisorption processes such as hydrogen bonding (<30 kJ/mol) and dipole bonding forces (2-29 kJ/mol). The Gaussian energies (1.04-2.09 kJ/mol) support the physisorption reactions in addition to zeolitic ion exchange processes. The thermodynamic functions (internal energy, free enthalpy, and entropy) demonstrate the exothermic, feasible, and spontaneous properties of the reactions. (C) 2022 Elsevier B.V. All rights reserved.