Heterogeneous photocatalytic treatment of organic dyes in air and aqueous media

This review focuses on the heterogeneous photocatalytic treatment of organic dyes in air and water. Representative studies spanning approximately three decades are included in this review. These studies have mostly used titanium dioxide (TiO2) as the inorganic semiconductor photocatalyst of choice for decolorizing and decomposing the organic dye to mineralized products. Other semiconductors such as ZnO, CdS, WO3, and Fe2O3 have also been used, albeit to a much smaller extent. The topics covered include historical aspects, dark adsorption of the dye on the semiconductor surface and its role in the subsequent photoreaction, semiconductor preparation details, photoreactor configurations, photooxidation kinetics/mechanisms and comparison with other Advanced Oxidation Processes (e.g., UV/H2O2, ozonation, UV/O3, Fenton and photo-Fenton reactions), visible light-induced dye decomposition by sensitization mechanism, reaction intermediates and toxicity issues, and real-world process scenarios. © 2008 Elsevier B.V. All rights reserved.

Critical training of mass media documentalists

This study takes the old myth of objectivity in media discourse to one of the most important but unrecognized actors in the process of its construction: the mass media information scientist or documentalist. Accepting the subjective presence of the documentalist in his/her productions, this article opts for the recognition and explicit statement of this role, recommending two actions. First, we suggest that public higher education institutions combine the technical training of mass media documentalists with training in critical thinking skills. Our study analysed the subjects covered in course syllabi to detect the deficiencies to be addressed in meeting this objective. Second, we propose alternative lines of training that can contribute to cross-training of mass media documentalists in those degree programs to ensure that they acquire the needed skills in critical analysis.