Fixed Bed Adsorption/Desorption of Valeric Acid from Aqueous Solution Using Granular Activated Charcoal

n this research, the capability of Granular Activated Charcoal (GAC) for adsorbing Valeric acid (VA) from an aqueous solution was investigated in a fixed-bed column. The effect of important parameters, such as flow rate, initial concentration, bed depth, and the temperature was considered. The maximum adsorption capacity was achieved equal to 750.93 (mg/g). Length of Mass Transfer Zone (MTZ), Length of Unused Bed (LUB), and Carbon Usage Rate (CUR) were calculated. Three dynamic models (Thomas, B-A, and Yoon-Nelson) were applied in different situations. The Yoon–Nelson and Thomas models were found suitable for predicting the initial part of breakthrough curves. The FTIR tests indicated that the adsorption of VA on GAC has mainly occurred physically. The feasibility of desorbing VA from saturated GAC was also determined. The column was regenerated by using deionized water in three cycles. The desorption percentage of Valeric acid in the second and third cycles were 73% and 35%, respectively.