Fixed bed adsorption/desorption of Valeric acid from aqueous solution using granular activated charcoal

Document Type: Research Article


1 University of Guilan, Rasht, Iran

2 Department of Chemical Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran


In this research, the capability of granular activated charcoal (GAC) for adsorbing Valeric acid (VA) from aqueous solution was investigated in a fixed-bed column. The effect of important parameters, such as flow rate, initial concentration, bed depth and 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 at different situation. The Yoon–Nelson and Thomas models were found suitable for prediction the initial part of breakthrough curves. The FTIR tests indicated that the adsorption of VA on GAC was 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 cycle were 73% and 35%, respectively.