Application of Box-Behnken design for optimization of malachite green removal from aqueous solutions by modified barley straw

Untreated wastewater can have important effects on the environment and human. The work aimed to evaluate the effectiveness of modified barley straw to remove Malachite Green (MG) from industrial wastewater. Studied variables were pH, contact time, initial malachite green concentration, and adsorbent dosage. Box-Behnken design method was used for modelling the process of adsorption. The results of the analysis of variance showed that there is a significance relative among process parameters. The high value of R-2 (0.9753) indicated that there was a high correlation between the predicted and experimental values. The removal efficiency of malachite green increased by increasing of modified barley straw dosage, pH and contact time, and decreasing of color concentration. Remove the color was better in alkaline conditions and the best pH was equal to 9.5. The optimum contact time to remove was 120 min. The findings of this study showed that the Box-Behnken model can efficiently optimize the malachite green adsorption onto modified barley straw from aqueous solutions.