Abstract:

The photochemical degradation of dimethyl phthalate(DMP) in aqueous solution was investigated via a comparative assessment in vario
us advanced oxidation systems (UV, H₂O₂, UV/H₂O₂, UV/Fe²⁺, Fenton and UV/Fenton). The degradation trends followed the following order: UV/Fenton>UV/H₂O₂>dark/Fenton>UV/Fe²⁺>UV>H₂O₂. It could be inferred from the studies that UV radiation enhanced the removal rate of DMP in the Fenton process and UV/Fenton was the most effective for the decomposition of DMP. According to the experimental result, the concentrations of Fe²⁺ and H₂O₂ and pH value were the three main factors that could greatly influence the degradation rate of DMP, and the effect of the factors followed the order: pH value>H₂O₂ concentration>Fe²⁺ concentration. The optimum conditions were obtained by orthogonal experiment at initial pH=3—4 for the UVFenton system, with original Fe²⁺ and H₂O₂ concentrations of 3.6×10^-4—7.2×10^-4 mol/L and 1.9×10^-2 mol/L, respectively.

Key words: UV-Fenton method, dimethyl phthalate(DMP), photodeg