Kinetics models Elovich , adsorption capacity at time [mg g−1 ]; , desorption constant of Elovich model [g mg−1 ]; t , time [min]; , initial sorption rate of Elovich model [mg g−1 min−1 ][25 ] Fractional power , fractional power model constant [mg g−1 ]; , rate constant of fractional power model [min−1 ][25 ] Pseudo-first-order , adsorption capacity at equilibrium [mg g−1 ]; , adsorption capacity [mg g−1 ] at time (min); , rate constant of the model [min−1 ] [26 ] Pseudo-second-order , rate constant of pseudo-second-order model [g mg−1 min−1 ]; , adsorption capacity at equilibrium [mg g−1 ][26 ] , initial adsorption rate [mg g−1 min−1 ]Isotherm models , maximum adsorption capacity [mg g−1 ]; , adsorption capacity at equilibrium [mg g−1 ]; , Langmuir model constant [L mg−1 ]; , adsorbate concentration at equilibrium [mg L−1 ][27 ] Langmuir , Hall separation factor [dimensionless]; , initial concentration of AB80 [mg L−1 ][28 ] , surface coverage [dimensionless][28 ] Freundlich , Freundlich model constant [mg g−1 ] ; , Freundlich model constant [dimensionless][27 ] Halsey , Halsey model constant [L g−1 ]; , Halsey model exponent [dimensionless][27 ] Dubinin-Radushkevich , adsorption energy constant [mol2 kJ−2 ]; , Polanyi potential [kJ mol−1 ][27 ] Sips , affinity coefficient ; , Sips model constant [dimensionless][27 ] Redlich-Peterson [L g−1 ] and , Redlich-Peterson model constants; , Redlich-Peterson model exponent [dimensionless][27 ] Toth , Toth model constant [L mg−1 ]; , Toth model constant [dimensionless] [27 ] Khan , Khan model constant; , Khan isotherm model exponent[27 ] Koble-Corrigan and , Koble-Corrigan model constants; , Koble-Corrigan isotherm exponent[29 ] Fritz-Schluender [mg g−1 ] , , Fritz-Schluender model constants; , Fritz-Schluender exponent [dimensionless][29 ] Thermodynamic models Arrhenius , activation energy [kJ mol−1 ]; R , gas constant; , Arrhenius constant[30 ] Eyring-Polányi , Boltzmann constant; , activation entropy change [kJ mol−1 K−1 ]; , activation enthalpy change [kJ mol−1 ][30 ] Gibbs free energy , Gibbs free energy change [kJ mol−1 ][30 ]