Equilibrium Studies for Dye Adsorption onto Red Clay

Abstract

In this study, it was aimed to remove malachite green, a cationic dye, from aqueous solutions by the adsorption method under various experimental conditions by using red clay. Red clay was used because it is abundant in nature and easily accessible in our region. In addition, it has been preferred as an adsorbent because it is used economically without any pre-treatment. The effects of initial malachite green concentration, temperature, adsorbent amount, and contact time on the adsorption process were evaluated. To examine the percent dye removal effect of the initial malachite green concentration, five different amounts of 25-150 ppm were examined. In order to examine the effect of the amount of red clay on the percentage of dye removal, five different amounts, in the range of 0.5-2 grams, were examined. In order to find the optimum time for the adsorption process, studies were carried out at four different values, 30-120 minutes. In the adsorption process of red clay and malachite green, experiments were carried out at three different degrees as 298, 313 and 333 K. After reaching equilibrium in the adsorption process, the data obtained were analyzed and studies were carried out by applying them to isotherm models. The results obtained from the adsorption process were compared with Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models. It has been determined that the experimental studies are more compatible with the Dubinin-Radushkevich model. According to the results, it is incompatible with the Langmuir model. Accordingly, it can be said that the adsorption takes place in a multilayer and heterogeneous form.

Keywords

• Dye removal
• Red clay
• Cationic dye
• Isotherm

References

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