Development of methods for the removal of dye using metal-doped alumina catalysts

Abstract EN

The present study is related to the removal of colorants.

Synthetic colorants represent a relatively large group of organic chemicals.

Such chemicals have undesirable effects not only on the environment but also on human beings.

Adsorption of dye such as Acid Red 4 on pure alumina and alumina supported metals was studied as a function of temperature, amount of adsorbent and shaking time.

Alumina was doped with divalent metals such as nickel and zinc by the impregnation technique, making the Ni 0.001–Al2O3, Ni0.01–Al2O3, Zn 0.001–Al2O3, Zn 0.01–Al2O3 adsorption systems.

A spectrophotometric technique was used for measuring the extent of adsorption.

The data were fitted in Langmuir, Freundlich, and Dubinin–Radushkevich isotherm equations and their corresponding constants were calculated from the slopes and intercepts of their respective lines.

Thermodynamic parameters such as enthalpy change (∆H), free energy change (∆G), and entropy change (∆S) of adsorption were calculated by using Langmuir’s constant K.

Sorption mean free energy (E) for each system were calculated by using the Dubinin–Radushkevich equation.