Photodegradation of 17β-estradiol in water by UV-vis/Fe(III)/H2O2 system

Photodegradation of 17β-estradiol (E2) in aqueous solutions by UV-vis/Fe(III)/H2O2 system, namely Photo-Fenton system, was preliminarily investigated under a 250 W metal halide lamp (λ ≥ 313 nm). The influences of initial pH value, initial concentration of H2O2 and E2 on photodegradation efficiency of E2 were discussed and the amount of CO2 produced by the photodegradation reaction was measured. The results indicates that E2 could be decomposed efficiently in UV-vis/Fe(III)/H2O2 system. Under the condition of 10.0 μmol L−1 Fe(III), 1000 μmol L−1 H2O2 and pH 3.0, the degradation efficiency of 18.4 μmol L−1 E2 reach 75.2% after the irradiation of 160 min. Over the range of pH 3.0-6.0, the higher acidity, the higher the degradation efficiency of E2 and initial reaction rate are. The degradation efficiency of E2 increases with increasing of initial concentration of H2O2 and with decreasing of initial concentration of E2. The E2 mineralization efficiency increases with reaction time but the mineralization efficiency was lower. When the initial concentration of Fe(III) and H2O2 were 10.0 and 1000 μmol L−1, respectively, the mineralization efficiency of 18.4 μmol L−1 E2 solution with pH 3.0 was only 21.6% after 160 min irradiation. It is suggested that the mineralization occurred probably only at aromatic ring.