Phenol Adsorption from Aqueous Solutions onto Activated Carbon Produced from Iraqi Date-Stones.

Abstract

This study is conducted to synthesize an activated carbon from date-stones using different concentration (20%,35%,50%) of phosphoric acid as activater. The carbon was soaked for 72 hours followed by carbonization at (500°C) for two hours. Specific surface area and pH were measured. The adsorption of phenol at different temperatures (283K , 293K , 313K , 333K) from aqueous solutions onto activated carbon was investigated .The determination of phenol concentration at equilibrium solution was measured using U.V. spectrophotometer with an adsorbance wavelength of (211nm). The activated carbon exhibited high ability to adsorbe phenol from aqueous solutions. The maximum adsorption rates were 98.76% , 98.9% and 97.5% at an initial concentration of ( 240 mg/l ) of phenol and at 333K for activated carbon , (20% ,35% and 50%) , respectively. Adsorption isotherm was studied using Langmuir and Freundlich isotherm models. The characteristic parameters for each isotherm and related correlation coefficient have been determind .The results showed that the adsorption process of the synthetic activated carbon fits very well with the Freundlich isotherm model and in a lesser degree with Langmuir isotherm model . Thermodynamic parameters such as ∆G°, ∆H° and ∆S° have also been evaluated and it has been found that the sorption process was feasible, spontaneous and endothermic.