Kinetic and thermodynamic studies of Brazilian illite–kaolinite in natural and intercalated forms as adsorbents to removal of Zn2+ from aqueous solutions

• The chemical modification was realized with new occurrence of Brazilian clay.
• The model of Adams–Bohart was used to analyze the adsorption experimental data.
• The spontaneity of adsorption systems, reflected in the negative Gibbs energies.
• The kinetic adsorption can be described by the pseudo-second-order rate equation.
• The maximum desorption capacities found were 96.61% for natural clay.

In order to find out new sources reactive materials, the performance of natural and modified-illite/kaolinite for zinc adsorption from aqueous solution was investigated in the present study. The organic/inorganic material was obtained the natural clay using the intercalation process with dimethyl sulfoxide. The objective of this study was to examine the adsorption behavior of Brazilian phyllosilicate sample and hybrid material, towards a divalent metal has been studies by a batch technique. The phyllosilicate sample and hybrid material were characterized by X-ray diffractometry (XRD), cation-exchange capacity determination, surface areas were obtained from nitrogen adsorption/desorption, and elemental analysis. The Avrami, Lagergren, chemisorption, and Intra-particle diffusion models for adsorption isotherms were applied in order to determine the adsorption capacity to form a monolayer and the constant related to the adsorption intensity. The adsorption equilibrium was established in 140 min for natural and 120 min for modified clay The maximum number of moles adsorbed was determined to be 12.56 and 22.91 mmol/g for systems Zn2+-(kaolinite/ilite) and Zn2+-(kaolinite/ilite + dimethyl sulfoxide), respectively.