Adsorption of crystal violet on kaolinite clay: kinetic and equilibrium study using non-linear models

This work studied the efficiency of Tamazert kaolinite clay for adsorbing the cationic dye crystal violet from an aqueous solution in a batch system. The kinetics of the process and the equilibrium of adsorption were studied using non-linear models. The characterization of Tamazert kaolinite clay showed that it has structural, textural and surface properties that are suitable for adsorption. The effects of various process parameters such as contact time, initial dye concentration, initial pH, adsorbent dose and temperature were tested. The kinetic study using non-linear regression showed that the pseudo-second order model best fitted the experimental data. The intra-particle model was also used to estimate the contribution of intra-particle diffusion to this process. The adsorption isotherms were fitted to Freundlich, Langmuir and Redlich-Peterson models, showing that the adsorption is limited to a monolayer with a monolayer adsorption capacity of 44.2 mg g(-1). The thermodynamic study indicated that the process is exothermic, spontaneous and accompanied by a decrease in entropy.

Automated summary

This study investigated the adsorption efficiency of Tamazert kaolinite clay for crystal violet dye in a batch system. Non-linear models were used to study the kinetics and equilibrium of the adsorption process. The characterization of the clay showed that it has suitable properties for adsorption. Various process parameters were tested, and the pseudo-second order model was found to best fit the experimental data. The adsorption isotherms were fitted to different models, indicating that the adsorption is limited to a monolayer with a specific adsorption capacity. The thermodynamic study revealed that the process is exothermic, spontaneous, and accompanied by a decrease in entropy.