Comparative study of MTBE photocatalytic degradation with TiO2 and Cu-TiO2

The photocatalytic techniques have been widely applied to the treatment of wastewaters. However, this work introduces an innovative application of photocatalysis to the treatment in continuous of gaseous contaminants. Packed reactors with different lengths and a spiral one have been designed to study the photocatalytic degradation of methyl tert-butyl ether (MTBE), individual alcohols and mixtures with their corresponding aldehydes. These studies have been performed with TiO2 (Degussa P-25) and TiO2 doped with Cu (Cu-TiO2). The results obtained have shown that these systems can degrade and mineralize the tested compounds, thus achieving the decontamination of their gaseous emissions. Additionally, the reactor with Cu-TiO2 has been more efficient than that with TiO2 at the degradation and mineralization of MTBE, being the photocatalytic behaviour of the former more easily altered by the presence of intermediates. Additionally, it has been observed that reactor morphology plays an important role in degradation efficiency. The spiral reactor with Cu-TiO2, in which the catalyst was thermally deposited on the inner walls, achieved the highest degradation and mineralization of MTBE. The obtained results are particularly interesting as an alternative to reduce emissions of volatile organic compounds to the atmosphere. (c) 2007 Elsevier B.V. All rights reserved.