keywords: Tea waste, activated carbon, adsorption, response surface methodology
The optimum adsorption conditions for the removal of methylene blue (MB) dye onto activated carbon produced from Nigerian tea waste were studied with the help of response surface methodology (RSM) statistical software. The effect of two adsorption variables (adsorbent dosage and adsorbate concentration) were investigated using central composite design (CCD), a subset of response surface methodology (RSM) with the targeted response being percentage removal of MB. The optimum adsorption conditions obtained were the adsorbent dosage of 0.7 g and the initial concentration of 87 mg L-1 with the desirability of 0.96. The predicted and experimental adsorption efficiency values for MB adsorption were 90.23 and 91.07%, respectively, showing desirable agreement between the experimental and the predicted value from the models with a relatively small error of 0.84. The results show that tea waste has the potential of being a very good precursor for activated carbon production.