Fate of Conjugated Natural and Synthetic Steroid Estrogens in Crude Sewage and Activated Sludge Batch Studies

Abstract

Steroids are excreted from the human body in the conjugated form but are present in sewage influent and effluent as the free steroid, the major source of estrogenic activity observed in water courses. The fate of sulfate and glucuronide conjugated steroid estrogens was investigated in batch studies using activated sludge grown on synthetic sewage in a laboratory-scale Husmann simulation and crude sewage from the field. A clear distinction between the fate of sulfate and glucuronide conjugates was observed in both matrices, with sulfated conjugates proving more recalcitrant and glucuronide deconjugation preferential in crude sewage. For each conjugate, the free steroid was observed in the biotic samples. The degree of free steroid formation was dependent on the conjugate moiety, favoring the glucuronide. Subsequent degradation of the free steroid (and sorption to the activated sludge solid phase) was evaluated. Deconjugation followed the first order reaction rate with rate constants for 17alpha-ethinylestradiol 3-glucuronide, estriol l6alpha-glucuronide, and estrone 3-glucuronide determined as 0.32, 0.24, and 0.35 h respectively. The activated sludge solid retention time over the range of 3-9 days had 74 to 94% of sulfate conjugates remaining after 8 h. In contrast, a correlation between increasing temperature and decreasing 17alpha-ethinylestradiol 3-glucuronide concentrations in the activated sludge observed no conjugate present in the AS following 8 h at 22 degrees C Based on these batch studies and literature excretion profiles, a hypothesis is presented on which steroids and what form (glucuronide, sulfate, or free) will likely enter the sewage treatment plant.

Influence of Operating Parameters on the Biodegradation of Steroid Estrogens and Nonylphenolic Compounds during Biological Wastewater Treatment Processes

“…The apparent biomass sorption (LogKp) values were 28 greater in the nitrifying/denitrifying works than those in the nitrifying/denitrifying works 29 with phosphorus removal for both steroid estrogens and alkylphenolic compounds 30 possibly indicating a different cell surface structure and therefore microbial population. 31 The difference in biological activity (mg tonne -1 ) identified in this study, of up to seven 32…”

Occurrence and fate of androgens, estrogens, glucocorticoids and progestagens in two different types of municipal wastewater treatment plants

“…This is most probably due to the conversion from other steroids with a similar structure, or hydrolysis of their conjugated forms (glucuronides and sulfates). 27,29 Overall, glucocorticoids had high degradation in each plant while androgens, estrogens and progestagens varied greatly between the two plants. The results from the present study showed that activated sludge treatment (Plant A) generally had a better capacity than oxidation ditch (Plant B) to degrade various steroids in sewage systems.…”

The effectiveness of anaerobic digestion in removing estrogens and nonylphenol ethoxylates

“…It was recognized by de Mes et al [15] that information on the role of conjugation in determining the fate of estrogens in all forms of wastewater treatment including anaerobic sludge digestion was lacking. However, it is known that sulphate conjugates are more stable than gluconarides [16]. Reports of the degradation of alkylphenol ethoxylates (APEOs) in anaerobic conditions are more scarce in comparison to steroid estrogens.…”