Removal of Tartrazine from Aqueous Solution by Adsorption on Activated Red Mud

Bacioiu, Ionela-Gabriela; Stoica, Ligia; Constantin, Carolina; Stanescu, Ana-Maria

Removal of Tartrazine from Aqueous Solution by Adsorption on Activated Red Mud

2017

Bacioiu, Ionela-Gabriela | Stoica, Ligia | Constantin, Carolina | Stanescu, Ana-Maria

In this study, activated red mud was used to develop an effective adsorbent in order to remove a toxic azo dye (tartrazine E102) from aqueous solutions. To increase the adsorption capacity, the red mud was activated by acid-heat treatment using 20 wt.% HCl (RM-HCl). To establish the optimum operating parameters, the influence of pH, adsorbent dose, contact time, initial dye concentration, and stirring rate was investigated. The adsorption equilibrium was studied using Langmuir, Freundlich, Dubinin-Radushkevich, Temkin isotherm models, and the characteristic parameters for each adsorption isotherm were determined. The kinetics of the adsorption process was analyzed by means of pseudo-first-order and pseudo-second-order models. The maximum removal efficiency obtained under optimum conditions was 84.72%. These results were in accordance with the isotherm and kinetic data. The results suggested that tartrazine adsorption process follows the pseudo-second-order kinetic model and also that fits Langmuir isotherm model. The maximum monolayer adsorption capacity was 136.98 mg/g.

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