Removal of Endocrine Disrupting Chemicals in Wastewater Treatment by Fenton-Like Oxidation

Abstract

The presence of endocrine-disrupting chemicals (EDCs) in wastewater effluent is a major concern to the scientific community. This research effort was aimed at investigating Fenton-like degradation of two EDCs 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). The results of the study showed that E2 and EE2 were effectively removed by the Fenton-like oxidation process. Removal efficiencies of 95% and 98% at ferric concentration of 1 × 10−3 M (58.6 mg l−1) were achieved for E2 and EE2, respectively. The kinetics of Fenton-like degradation of E2 and EE2 were adequately described by the pseudo second order kinetic model. Values of 27.8 and 22.5 kJ mol−1 were obtained for the activation energy for E2 and EE2, respectively, from the Arrhenius-type plot, showing that the process does not just involve radical reactions but also intermediate reaction steps involving radical–molecule or ion–molecule reactions. The presence of high dissolved organics in wastewater significantly reduced the removal efficiencies. The reaction by-products for E2 and EE2 were more stable to the oxidation process and more readily biodegradable. Fenton-like oxidations therefore offers a promising alternative for the removal of these EDCs in wastewater treatment applications at the tertiary treatment stage.