Degradation of dibutyl phthalate by homogeneous photocatalysis with Fe(III) in aqueous solution

摘要

The degradation of dibutyl phthalate (DBP) photoinduced by Fe(III) in aqueous solution has been investigated under monochromatic irradiation and sunlight, Hydroxyl radicals ~centre dotOH, responsible of the degradation, are formed via an intra-molecular photoredox process in excited Fe(III) aquacomplexes. The concentration in Fe(OH)~(2+) in the starting Fe(III) solution appears to be a controlling parameter of the degradation rate, as already stated in our previous works. The first step of the decomposition of DBP involves the hydrogen abstraction on the butyl chain mainly on the carbon in #alpha#-position to aromatic ring. The major primary photoproducts are hydroxy, dihydroxy and carboxylic derivatives. For prolonged irradiations, DBP and its photoproducts are completely mineralized due to the regeneration of the absorbing species and the continuous formation of ~centre dotOH radicals that confers a catalytic aspect to the process. Consequently, the degradation photoinduced by Fe(III) could be an efficient method of DBP removal from water.