Kinetics, Thermodynamics and Adsorption of BTX via Date-Palm Pits Carbonization I Aqueous Solution

Activated carbon has been the most widely used as adsorbent , which is a versatile adsorbent due to its large area, porous structure, high adsorption capacity and variable surface chemical composition. Benzene, toluene and xylene( BTX) compounds are toxic organic compounds that appear in underground water resources as results of leakage from underground fuel tanks and also improper waste discharge of oil and petrochemical industries. In this work, Palm date pits(Majhool) were used as the precursor in the preparation of activated carbon. The date pits were first washed with water to get rid of impurities, dried at 110 °C for 24 h, crushed, then it was mixed with FeCl3, AgNO3 and CuSO4•5H2O solution (as activating agent) at an impregnation ratio of 1:2 for 24 h at room temperature. The impregnated samples were next dried at 110°C. A stainless steel reactor was used for the carbonization of dried impregnated sample. The reactor was placed in a tube furnace and heated to reach an activation temperature (700°C ). Adsorption of BTX compounds from water by using activated carbon produced from date palm pits activated by FeCl3 was investigated in terms of contact time, adsorbent dose, temperature, pH and BTX concentration. Results indicated that the adsorption effectiveness was increased with increasing the pH , dose amount and the contact time. On the other hand, the adsorption efficiency was found to increase with decreasing the temperature. The equilibrium adsorption isotherm was explained using Langmuir and Freundlich models. BTX adsorption was better represented by Langmuir model. The kinetic of adsorption was studied using pseudo-first order, pseudo-second order and intraparticle diffusion. It was found that the adsorption followed pseudo-second order. Adsorption thermodynamic parameters for BTX adsorption such as standard enthalpy ΔH°, standard entropy ΔS° and standard free energy ΔG° were calculated. The shape, size and surface area of the samples were determined using SEM, iodine number and BET. The effect of activating agent on the adsorption efficiency of BTX was also studied.