Preparation of activated carbon from olive mill solid residue

A process was developed for producing high quality activated carbon from Al gerian mill waste. The solid olive mill residue was carbonized at 800 degre es C and physically activated with CO2, air or steam. An optimum activation temperature of about 850 degrees C was determined for all the activation a gents used. Steam appeared to be the most efficient activator as compared w ith air and CO2. An optimal activation time of about 2 h was then determine d with steam as the optimum activation agent. The porous structure of the a ctivated carbon was characterized by nitrogen adsorption at - 196 degrees C , and in all cases the surface areas, calculated by DR and BET methods, con firmed the production of a material with good microstructural characteristi cs and specific surfaces exceeding 1500 m(2) g(-1) for the carbon prepared by steam activation. Phenol adsorption isotherms gave the adsorption proper ties and the adsorption capacity of about 11.24 mg of phenol per gram of th e activated carbon produced. The kinetics of the phenol adsorption onto the porous material was evaluated by means of two models: the external resista nce model and the linear model. The second model appeared to constitute a m ore appropriate fit for the experimental data. (C) 2000 Society of Chemical Industry.