Removal of Acid Blue 113(AB113) dye from aqueous solution by adsorption onto activated red mud: a kinetic and equilibrium study

Dyes are among the most important sources of environmental pollutants which are found in wastewater of different industries such as textile manufacturing industries and are harmful for human health and environment. The purpose of this study was to assess removal of AB113 dye from aqueous solution by its adsorption onto activated red mud as a cheap adsorbent.

This study was a laboratory study. At first red mud was activated by adding 20 ml nitric acid for each 10 gr of red mud for 24 hours, and dried out in 150 0C for 4 hours. Acquired equilibrium time was determined which was 60 min. The effect of pH, contact time and initial AB113 dye concentration, kinetic and isotherm models were studied at constant equilibrium time. Data were interpreted and analyzed by Excel software and regression coefficient.

Increased pH and increased initial dye concentration led to decreased rate of dye removal. But dye removal increased by increasing contact time. The results showed that AB113 adsorption follows Longmuir isotherm (R2= 0.9943, qe= 0.172 mg/g) and pseudo second order models (R2= 0.9999, qe= 3.86 mg/g) to a greater degree. Considering the constant distribution coefficient, with increasing initial amount of red mud adsorbent surface became homogeneous.

The results of this study showed that red mud can be used as a fast, effective and cheap adsorbent with high efficiency for the treatment of textile manufacturing wastewater.