Recently, it has been determined that various synthetic and natural compounds can mimic or interfere with the action of natural hormones and disrupt the endocrine systems of humans and wildlife. These substances, collectively referred to as endocrine-disrupting compounds (EDCs) have been linked to a variety of adverse effects in both humans and wildlife. Numerous EDCs, most of which act as estrogens, have been detected in various surface and groundwaters.

A major source of estrogens in rivers appears to be treated wastewater effluent. Investigations worldwide have detected bioactive estrogens in waters receiving treated wastewater. Municipal wastewater is a complex mixture of natural and synthetic organic chemicals. The most powerful EDCs that are common in treated wastewater include natural hormones 17Beta-estradiol (E2), its breakdown product, estrone (E1), and 17alpha-ethinylestradiol (EE2), the synthetic estrogen used in birth control pills. Other non-steroidal organic chemicals have been shown to possess estrogenic activity, but are much weaker than the steroid hormones. These include the degradation of nonionic surfactants, such as alkylphenolethoxylates and plasticizers. Current technologies for treating municipal wastewaters are only partially successful at removing EDCs. Steroid hormones are especially difficult to remove completely. They contain “steroid rings” that are resistant to degradation by the microorganisms used in wastewater treatment plants. Not only are steroids not efficiently removed from the waste, but those not removed are actually activated by the treatment. As a result, both natural and synthetic estrogens and their degradation products tend to pass through wastewater treatment systems in bioactive forms and can reach concentrations in receiving streams sufficient to produce deleterious biological effects on organisms living in the waters.

This project investigates the effectiveness of various advanced oxidation process (AOP) techniques in degrading the two most potent steroids (E2 and EE2) in aqueous solution, and analyzes water and sediments in rivers in the Birmingham, Alabama area receiving treated wastewater to determine whether the estrogens are present in concentrations sufficient to disrupt endocrine systems of aquatic organisms in the receiving waters. Advanced oxidation processes studied include: ozonation, hydrogen peroxide, sonication, UV light, and combinations thereof. Effectiveness of the treatments are assessed and reported using quantitative chemical analysis using HPLC (indicating the extent to which the amount of the steroid in the spiked sample has been reduced by a given treatment, and also shows the accumulation of breakdown products). A cell-based estrogen screen assay is used to determine whether the treated sample retains biological (estrogenic) activity.