No Catalyst Dye Photodegradation in a Microemulsion Template

This paper proposes an innovative solution for the efficient dye degradation from water treatment plant effluent, using microemulsion assisted photodegradation without the addition of a solid catalyst. Total photodegradation of dyes was achieved using for the first time a process based on combined photocatalytic effects of the water/oil interface processes and the potential activity of ethyl acetate as a UV initiator. The catalytic effect of nanostructured fluids based on the carboxylic oil phase is an absolute scientific premiere, and microemulsion assisted photodegradation processes open a new direction to pollutants photodegradation approach, exceeding the performances of both homogeneous and heterogeneous catalysis. The phenomenological modeling, with and without initiator, on both homogeneous and heterogeneous systems showed that the photodegradation of cationic and anionic dyes in a water/nonionic surfactant/ethyl acetate microemulsion is a radical process based on a chain reaction scheme. The complete photodegradation of cationic (Crystal Violet) and anionic (Methyl Orange) dyes in the microemulsion system occurs in 25 and 20 min, respectively, after an induction period of 5 min. The surfactant was recovered and reused in four successive processes, and for the degradation of 3.23 mg dye, 1 g of surfactant was used.