Oxidation of Natural and Synthetic Hormones by the Horseradish Peroxidase Enzyme in Wastewater


Steroid estrogens, including both natural estrogens (e.g., estrone - E1; 17β-estradiol - E2; and estriol - E3) and synthetic estrogens (e.g., 17α-ethinylestradiol - EE2), are known as endocrine-disrupting compounds. the objective of this research was to evaluate the feasibility of the enzymatic oxidation of estrogens and to optimize this process in municipal wastewater contaminated with steroid estrogens using horseradish peroxidase (HRP) and hydrogen peroxide. an initial HRP activity of 0.02 U ml-1 was sufficient to completely remove EE2 from the synthetic solution, although greater HRP doses (up to 0.06 U ml-1) were required to remove E1, E2 and E3. the optimal molar peroxide-to-substrate ratio was determined to be approximately 0.45. based on the Michaelis-Menten kinetics, the HRP had an increasing reactivity with E1, E3, E2, and EE2, in increasing order. in real activated sludge process effluent, an HRP dose of 8-10 U ml-1 was required to completely remove all of the studied estrogens, while only 0.032 U ml-1 of HRP was necessary to treat synthetic water containing the same estrogen concentrations. © 2007 Elsevier Ltd. All rights reserved.


Civil, Architectural and Environmental Engineering


International Council for Canadian Studies, Grant None

Keywords and Phrases

17α-ethinylestradiol; 17β-estradiol; Activated sludge; Endocrine-disrupting compounds; Enzymatic oxidation; Estriol; Estrogen; Estrone; Horseradish peroxidase (HRP); Michaelis-Menten kinetics; Steroid; Wastewater

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Article - Journal

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© 2024 Elsevier, All rights reserved.

Publication Date

01 Jan 2007

PubMed ID