(517a) Treatment of Endocrine Disrupting Compounds in Water

Historically, compounds such as substituted phenols, non-biodegradable chlorinated solvents, pesticides and surfactants, are recognized as examples of substances that are difficult to remove from water. Recently, pharmaceuticals and personal care products (PPCPs) and especially endocrine disrupting compounds (EDCs) are considered as emerging contaminants, which means that they are still unregulated or in the process of formulating regulations.

There is growing evidence of the impact of these emerging contaminants in the environment. Studies have shown that male fish in detergent-contaminated water express female characteristics, turtles are sex-reversed by polychlorinated biphenyls (PCBs), male frogs exposed to a common herbicide form multiple ovaries, pseudohermaphroditic offspring are produced by polar bears, and seals in contaminated water have an excess of uterine fibroids. Recent work shows that human development can also be feminized by exposure to estrogenic chemicals.

As an example, passive sampling is highly complimentary to spot sampling in environmental analysis. A polar organic chemical integrative sampler (POCIS) was extensively tested to optimize its performance under both controlled and field conditions. Under laboratory conditions, the kinetics of compound uptake by POCIS were linear during 10-day of exposure. POCIS sampling rates of the target compounds were significantly greater using polyethersulfone instead of polysulfone membrane, and was enhanced with increasing sorbent exposure area. Both spot and passive sampling demonstrated that most of the target chemicals were frequently detected in sewage effluent and river waters, and that the daily changes in the pollutant concentrations were greater for pharmaceuticals than for EDCs. The aqueous concentrations of all compounds were elevated at a sewage outfall, which has been confirmed to be an important source of the target compounds in rivers. The validated POCIS was successfully used to estimate the concentrations of the target compounds in effluent and river water, which were in good agreement with those from spot sampling for pharmaceuticals.

Advanced oxidation processes (AOPs) constitute a promising technology for the treatment of wastewaters containing pharmaceuticals and personal care products (PPCPs) and especially EDC's. AOPs are characterized by the generation of hydroxyl radicals. Besides fluorine, the hydroxyl radical is the strongest known oxidant. Therefore, it is possible for the hydroxyl radical to oxidize and mineralize almost every organic molecule into carbon dioxide (CO2) and inorganic ions. The most common advanced oxidation technique used at the industrial level is the Fenton's reagent process, which uses an iron salt and hydrogen peroxide.

The challenge of EDC's is that some exist in a steroid ring that is very difficult to degrade by standard methods used in waste water treatment systems to remove pathogens. 17?Ñ-ethinylestradiol (EE2), the synthetic estrogen commonly found in birth control pills, is one such compound. Using AOP's (Fenton's reagent, hydrogen peroxide and ozone) in combination with other prospective treatment methods (sonication and UV), a solution of EE2 was subjected to treatments of varying methods, durations and intensities. These treated solutions were analyzed using high performance liquid chromatography (HPLC) in order to evaluate their effectiveness in degrading the endocrine disrupting compound EE2 in wastewater.