PREPARATION OF ACTIVATED CARBON FROM CHERRY STONE VIA PHYSICAL ACTIVATION AND THEIR APPLICATION FOR PHENOL REMOVAL

摘要

Phenolic compounds are very harmful to organisms even at low concentrations due to its toxicity and carcinogenicity properties. Thus, it is fully recommended to remove the phenol from industrial effluentsbefore entering the water streamfl]. The treatment of wastewater with activated carbon is considered to be an effective method for the removal of phenol from waste solution because of its large surface area, micro-porous nature, high adsorption capacity, high purity and easy availability[2]. Activated carbon can be produced by physical or chemical activation. The physical activation method consists of two different steps. In the first one -carbonization- the raw material is thermally treated under nitrogen atmosphere and a carbonized material with an ,, incipient porosity is obtained. In the second step -activation-the carbonized material previously prepared is subjected to thermal treatment in the presence of a gasifying agent such as carbon dioxide, steam or air at a given temperature. The main advantage of physical activation over chemical activation is that it avoids the incorporation of impurities coming from the activating agent, which may affect the chemical properties of the activated carbon. As a consequence of the activation step, a certain mass of the carbonized material is lost due to the formation of gaseous carbon oxides. The bum-off percent influences the textural properties of the activated carbons although, in general, the materials produced in this manner usually show a well-developed surface area and porous texture[3]. Activated carbons are produced from a variety of carbonaceous materials. The choice of precursor largely depends on its availability, cost, and purity, but the manufacturing process and intended applications of the product are also important considerations. Therefore evaluation of biomass is getting increased attention in all over the world as it is renewable, widely available, cheap, and environmental friendly [4]. In this study activated carbon was produced from cherry stone by physical activation using steam as activating agent.The prepared activated carbon was used as an adsorbent for phenol removal.The adsorption parameters such as pH, adsorbent dosage, initial phenol concentration, contact time and temperature were examined.