Degradation of dimethyl phthalate (DMP) in aqueous solution by UV/Si–FeOOH/H2O2

This paper considers the degradation of dimethyl phthalate (DMP), a highly toxic endocrine disrupter, by a novel Fenton reaction involving a new catalyst Si–FeOOH with H2O2 under UV365 irradiation. Si was selected for its non-toxic and less secondary pollution and the new catalyst Si–FeOOH was synthesized by adding Si to the amorphous FeOOH. The experiment showed that the physical strength of new catalyst Si–FeOOH was enhanced when Si/Fe was 0.2 and the opportunity of dissolved iron was also reduced. The efficiency of DMP degradation by UV/Si–FeOOH/H2O2 could reach 97% after 30 min reaction time at pH 5, 0.5 g/L dosage of Si–FeOOH, and 2.0 mmol/L of H2O2 under 125 W UV365 irradiation. DMP could be degraded effectively by synergistic effect of UV, Si–FeOOH and H2O2 due to the catalytic absorption and free radicals reaction of FeOOH under the UV irradiation. The Si–FeOOH photocatalyst can be very easily recycled and the efficiency of DMP photodegradation can also remain 87.1% after six runs of DMP degradation.