ADSORPTION OF PHENOL FROM AQUEOUS SOLUTIONS USING ENGINEERED AND NATURAL ADSORBENTS

Abstract

This thesis conducted an investigation on the ability of six different adsorbents (aluminum oxide, zinc oxide, titanium dioxide, kaolin, fuller’s earth, and bentonite) to remove phenol from aqueous solutions through adsorption. The points of zero charge for aluminum oxide, zinc oxide, titanium dioxide, kaolin, fuller’s earth, and bentonite were found to be 9.0, 7.2, 6.9, 5.9, 8, and 7.7 respectively. Adsorption of phenol as a function of pH level was studied. Results revealed increase in removal efficiency with decrease in pH value. The highest removal efficiencies for aluminum oxide and zinc oxide, titanium dioxide, kaolin, fuller’s earth, and bentonite, respectively, at adsorbent pH = 4.5 and 0.5 g were 45.2%, 36%, 41.5%, 50%, 36.7%, and 61.1% respectively. Various kinetics models were studied and Phenol uptake onto all adsorbents can be expressed by Psuedo-second order kinetics. As for equilibrium studies not all adsorbents were best described by the same isotherm model. As Frendluich isotherm best describes aluminum oxide, bentonite, and fuller’s earth studies, Whereas Temkin isotherm best describes kaolin and zinc oxide, As for titanium, Dubinin-Radushkevich isotherm best described its equilibrium data. FTIR and SEM were used in conducting investigation on adsorbents with results revealing adsorption occurrence.