HETEROGENEOUS PHOTOCATALYSIS - DEGRADATION OF ETHYLBENZENE IN TIO2 AQUEOUS SUSPENSIONS

Heterogeneous photocatalysis in TiO2 aqueous suspensions has been used as a technique for the total destruction of organic compounds, such as ethylbenzene, in water. The photocatalytic degradation of ethylbenzene follows pseudo-first-order kinetics in a concentration range between 3 and 50 muM. Studies have shown that a Langmuir-Hinshelwood equation form can describe the initial rate of ethylbenzene disappearance. The objective of our research was to examine the degradation of intermediates species produced by the oxidation of ethylbenzene. The temporal course of the degradation was followed by high performance liquid chromatography. Gas chromatography-mass spectrometry analysis of the reactor solution from a ethylbenzene experiment revealed the presence of several intermediate species, namely 4-ethylphenol, acetophenone, 2-methylbenzyl alcohol, 2-ethylphenol and 3-ethylphenol. The influence of pH on the photocatalytic degradation of ethylbenzene was examined for initial 50 muM solutions at two different pH values. This study shows that the degradation of ethylbenzene at higher pHs requires a much longer illumination time to attain quality standards of drinking water.