Photocatalytic degradation of high concentration paraquat solutions [Degradación fotocatalítica de soluciones de alta concentración de paraquat] Article uri icon

abstract

  • The photocatalytic degradation of aqueous paraquat solutions with titanium oxide illuminated with ultraviolet light (365 nm) was investigated. Several kinetic experiments were carried out to investigate the effect of the following reaction parameters: catalyst weight, kind of dissolved gas in the reaction mixture, flow of oxidizing gas and paraquat initial concentration. These experiments indicated that paraquat molecules are converted to some intermediate organic products that are finally converted to CO2. Small amounts of catalyst in the order of 0.05 and 0.3 g TiO2 / 100 cm3 of solution are required to completely mineralize all the organic molecules in solution. Oxygen must be supplied to the reaction system to assure a good efficiency of the photocatalytic process. Paraquat photocatalytic reaction follows a pseudo first order rate expression with respect to reactant concentration.

publication date

  • 2003-01-01