Removal of Orthotolidine from Aqueous Solution Using Activated Carbon Synthesized from Heavy Crude Oil Waste

Abstract

In this research, activated carbon (A.C) and non-activated carbon (N.A.C) have been produced from heavy crude oil waste by distillation operations, carbonization and activation. Anhydrous zinc chloride (ZnCl2) (10% W/V) have been used for activation process with temperature of (500) ºC.Adsorption processes of Orthotolidine on the surface of (A.C) and (N.A.C) have been studied at (pH = 7) with various periods for contact (10-120) minutes and with temperatures of (283, 293, 303, 313) K, using solutions of (50, 100, 150, 200) mg L versus grain size of carbon (Mesh 70). The results showed that the percentage of adsorption increases with increasing of temperature and contact time.The highest percentage of adsorption of Orthotolidine reached to (99.00) %, using (A.C) and solutions of (100 mg L) concentration at contact time of (120 minutes) and temperature of (313 K), whereas a higher percentage of adsorption of Orthotolidine reached to (97.36) %, using (N.A.C) at the same previous conditions.Equations of Frendlich, Langmuir and Temkin have been applied on the adsorption processes. The results showed that all of the equations fit with adsorption processes according to correlation factor values (R2). The thermodynamic functions have been calculated. Values of (ΔGº) showed that the adsorption processes were spontaneous. Values of (ΔHº) showed that the adsorption processes were chemisorption and endothermic.