Technical Proceedings of the 2009 Clean Technology Conference and Trade Show

Clean Technology 2009

Chapter 7: Water, Waste and Remediation

S. Sinha, N.G. Tapia-Orozco, D.S. Acosta-Ramírez, R. Rodríguez-Vázquez
273 - 276
photocatalysis, DDT, surfactant, TiO2/UV
The toxic effects from the use of pesticides are of great concern to the environment. The pesticides containers are not treated according to the Mexican normativity and hence increase the pollutant levels in the environment, so we propose to clean these containers with surfactant for a further photocatalytic TiO2 treatment. Recently it has been demonstrated that semi conducting nanomaterials mediate the photo catalytic oxidation of the organic compounds that degrade pollutants. When the semi conductors are exposed to UV light, redox reactions occurs at the surface of the catalyst generating, hydroxyl radicals and superoxide ions which induces the oxidation process. The use of surfactants could increase the pesticides removal from the containers that can be degraded through remediation by photocatalysis, however, the presence of this surfactant could inhibit the free radicals produced during the catalysis. Conclusion: After this study we conclude that the best result for the degradation is found to be at 200ml/L air flow and CMC concentration of the surfactant. This surfactant concentration does not inhibit the generation of free radicals involved in pesticides photocatalytic degradation, the degradation time is reduced to 40 minutes for o,p-DDT and DDE, and to 10 minutes for p,p-DDT
Effect of surfactant on TiO2/UV mediated heterogeneous photocatalytic degradation of DDT in contaminated water