Adsorption Study of Textile Dye Basic Red 46 on Clinoptilolite

The study investigates the application of clinoptilolite for the elimination of textile basic dye from water. It is about modeling the process of dye adsorption from an aqueous solution to a natural adsorbent. The natural adsorbent-clinoptilolite is originally from Serbia, it has been characterized by chemical analysis which determined that SiO2 dominates (58.23%). The most common mineral phase in clinoptilolite is a mineral from the group of clinoptilolite with a mineral content in the tuff of about 85%. The concentration of basic dye and adsorption time were varied in the study (20–120 mg/dm3 and 2-60 min), while the amount of clinoptilolite was constant (1 g). Two-, three-, four- and five-parameter models were used to describe the adsorption process. The two-parameter Langmuir linear model perfectly describes equilibrium adsorption, whereas the Radke-Prausnitz isotherm proved to be the best of the several parametric models (R2=0.999). In kinetics, the dominance of the Pseudo-second order adsorption mechanism was confirmed. According to the results, it can be said that clinoptilolite is an effective adsorbent for removing the basic dye from an aqueous solution.