Adsorption of Phenolic Compounds and Methylene Blue onto Activated Carbon Prepared from Date Fruit Pits

Abstract

Activated carbon has been prepared from date fruit pits. The carbon, prepared at different burn-off rates, showed a high uptake of methylene blue. At 92 % burn-off (weight loss percent of the carbonized pits upon activation), methylene blue uptake was 590 mg/g. With this high capacity, the carbon was then used to study the adsorption of phenol, 2-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol. The prepared activated carbon showed an adsorption capacity better than that of many activated carbons in current use. The experimental adsorption data for the single components were regressed using both Langmuir and Freundlich isotherm models and the fit was generally satisfactory. The experimental adsorption data of the binary system phenol-2-nitrophenol were compared with the predicted results using two predictive models: the generalized Langmuir and the IAS models. The data were better represented by the IAS theory than the generalized Langmuir model even though the fit of the experimental data was not adequate.