The adsorption isotherms of AB193 onto BTMAbentonite were analyzed according to Langmuir, Freundlich
and D–R models. All of three-isotherm models for AB193 adsorption were fitted very well with the experimental equilibrium
data. The mechanism of the dye–BTMA-bentonite interaction is thus likely to be very complicated involving a
wide range of sites differing in a number of aspects including energy considerations.