Abstract

Natural clay being locally abundant and cheap material in Algéria can be easily activated to become a promising adsorbent for phenol removal from aqueous solution. The natural clay before and after activation was characterized using XRD and IR techniques. The effects of various experimental parameters, such as initial phenol concentration, temperature, pH, contact time and adsorbent done on the adsorption extent were investigated. Langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data fitted very well with this model. The activated natural clay had the monolayer adsorption capacity equal to 15 mg/g at pH value of 5.0 and 23°C, adsorption measurements show that the process is very fast and physical in natural clay. The extent of the phenol removal increased with the decrease in the initial concentration of the phenol and contact time of solution. The results showed that as the amount of the adsorbent was increased, the percentage (%) of phenol removal increased accordingly. Thermodynamic parameters showed that the adsorption of phenol on activated natural clay was exothermic.

Key words: Phenol, activated clay, adsorption isotherm, thermodynamic parameters, montmorillonites, adsorbent, x-ray diffraction.