FIXED-BED ADSORPTION OF CONGO RED ONTO TEA WASTE IN THE PRESENCE OF Fe2O3 NANOPARTICLES: AN EXPERIMENTAL AND MODELING STUDY

In this study، tea waste (TW) is employed for the removal of Congo red (CR) from aqueous solutions in a fixed-bed column at 30 °C. The breakthrough curves of the adsorption process of CR on TW at three different flow rates are determined. The results revealed that the breakthrough curves were dependent on flow rates in a manner in which a lower flow rate was in favor of the CR adsorption in the column-mode process. As the flow rate increased from 4. 6 to 6. 6 mL/min، the amount of dye uptake capacity decreased from 1. 78 to 1. 53 mg/g. The effect of the presence of Fe2O3 on the adsorption of CR on TW is also studied at 30 °C. The results showed that the presence of nanoparticles increased the adsorption uptake of CR by about 32%. Moreover، four novel models are developed for the prediction of the breakthrough curves resulted from the experimental data. The results of the models were in good agreement with experimental data (R2>0. 99). The statistical parameters confirm the suitability of the models.