Adsorptive Removal of Acid Blue 80 Dye from Aqueous Solutions by Cu-TiO₂

Table 1

Kinetic, isotherm, and thermodynamic models.

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 [mol^2 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]