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

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 17 beta-estradiol (E2) and 17 alpha-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 x 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.