The uptake of Eriochrome Black T dye from aqueous solutions utilizing waste activated sludge: Adsorption process optimization using factorial design

In the present study, the sorption of Eriochrome Black T dye from aqueous solution on waste sludge was investigated by employing the factorial design method. Currently, there are worldwide interests to using inexpensive and commercially available adsorbent materials for contaminant removal. Design expert software was employed to examine the influence of different concentrations of dye, adsorbent dosage, contact time and pH on the removal efficiency of Eriochrome Black T using sludge. Additionally, the factorial design was applied to examine the interaction effect of these four variables on the adsorption process. The results were also subjected to examine the correlation between the actual and theoretical EBT dye removal efficiencies (%) which showed how closely the predicted distribution results followed the experimental values. Moreover, the experimental results were subjected to Halsey and Jovanovic adsorption isotherms to explain the adsorption process. The experimental data followed Jovanovic model with higher R2 (0.9997) than the Halsey model.