Collect. Czech. Chem. Commun. 2001, 66, 676-684

Effects of pH, Temperature and Various Anions on Thiourea Disappearance in Aqueous Media with Titanium Dioxide Under UV-Irradiation. Photomineralization Kinetics

Abdelghani Boussaouda,*, Gerard Ducb, Jean Pierre Meilleb and Michelle Petit-Ramelb

a Laboratoire de Chimie-Physique, Faculté des Sciences, Agadir, Morocco
b Laboratoire d'Instrumentation et de Chimie Analytique II, Université Claude Bernard, Lyon I, France


Disappearance of thiourea in aqueous suspensions of TiO2 or ZnO occurs under near-UV irradiation. The effects of some parameters such as initial concentration of thiourea, temperature, pH and common inorganic anions were examined. The results indicate that the process follows the Langmuir-Hinshelwood type kinetics. In the presence of anions such as nitrates, chlorides and sulfates, the initial disappearance rate of thiourea at pH 6 drops. It is found that the initial rate of thiourea disappearance increases when temperatue of reaction mixture increases. Finally, kinetics of thiourea photomineralization to nitrite, nitrate, sulfite and sulfate are established.

Keywords: Thiourea; TiO2; Kinetics; Photodegradation; Photooxidation; Photomineralization; Semiconductors.

References: 23 live references.