Removal of Phenol by Using Montmorillonite,Clinoptilolite and Hydrotalcite

This work is to study the removal of phenol from aqueous solutions by adsorption using three different adsorbents, clinoptilolite, montmorillonite, and hydrotalcite (HT). Except for montmorillonite, the other adsorbents were treated. Clinoptilolite was modified using cetyltrimethylammonium bromide (CTAB) and hydrotalcite was calcined by heating to 550C. Adsorption isotherms of phenol on all of the mentioned adsorbents was determined by using the batch equilibration technique and indicated that, the adsorption behavior could be modelled by using the Modified Freundlich equation. The differences observed in the isotherms were explained by the variations in adsorbent-adsorbate interactions under the effects of the different surface structures of adsorbents and the pH dependent ionization behavior of phenol. Calcined hydrotalcite (HTC) was found to be the best among the studied adsorbents since it can adsorb 52% of phenol from a solution containing initially 1 g/L phenol for the 1/100 adsorbent solution ratio while the others can adsorb only 8% of phenol for the same concentration and adsorbent solution ratio.