Decolourization of Acid Orange 7 Dye from Aqueous Solution by Adsorption on NaOH Treated Eggshells in Continuous Fixed Bed Reactor Application using Response Surface Methodology: Optimization by Box–Behnken Design.

NaOH Treated Eggshells (TES) was investigated for the removal of Acide Orange 7 (AO7) from aqueous solution using the continuous method was modeled by response surface methodology (RSM) and was optimized using Box–Behnken design (BBD) . Fixed bed adsorption has become a frequently used in wastewater treatment processes. Various low cost adsorbents have been studied for their applicability in treatment of different types of effluents. In this work, the intention of the study was to explore the efficacy and feasibility for azo dye, AO7 adsorption onto fixed bed column of TES. The effect of operating parameters such as flow rate, initial dye concentration, and bed height were exploited in this study. The studies confirmed that the breakthrough curves were dependent on flow rate, initial dye concentration solution of AO7 and bed depth.The precision of the equation obtained by Box–Behnken design (BBD) utility for modeling and optimization by response surface methodology RSM was confirmed by the analysis of variance (ANOVA) and calculation of correlation coefficient relating the predicted and the experimental values of removal of dye. The results revealed a good agreement between the predicted values, as obtained by the model, and the experimental values for AO7. The optimum conditions proposed by Box–Behnken design (BBD) to reach the maximum dye removal through adsorption process. Under the optimum conditions, the removal efficiency of AO7 were 89.89%.The application of response surface methodology in order to optimize using Box–Behnken design (BBD) . The research on modeling adsorption by RSM has been highly developed and The TES was shown to be suitable adsorbent for adsorption of AO7 using fixed-bed adsorption column.