Modelling of Fixed Bed Column Adsorption of Cationic Surfactant on Silica Gel

The adsorption of cationic surfactant (CS) on silica gel in a continuous flow type packed bed reactor was studied in detail. The column having 2.5 cm internal diameter, with different bed depth such as 30, 40, 50 and 60 cm were used. The initial CS concentration was 2000 mg/l and the flow rate through the packed bed was 10 ml/min. The data generated from column study was analysed using bed depth service time (BDST) model. Different column design parameters like depth of exchange zone, time required for exchange zone to move its own height, adsorption rate, adsorption capacity, etc. were calculated. The adsorption rate constant (K) and adsorption capacity (N $_o$ ) were found to be 0.00122 1/mg–h and 32,330 mg/l respectively. Effect of flow rate and initial concentration were also studied. Desorption of CS from the silica gel surface was possible using 18% HCl.