Removal of estrogenic activity of natural and synthetic hormones from a municipal wastewater: efficiency of horseradish peroxidase and laccase from Trametes versicolor.

Some researches studied the removal of steroid estrogens by enzymatic treatment, however none verified the residual estrogenicity after the enzymatic treatment at environmental conditions. In this study, the residual estrogenic activities of the key natural and synthetic steroid estrogens were investigated following enzymatic treatment with horseradish peroxidase (HRP) and laccase from Trametes versicolor. Synthetic water and municipal wastewater containing environmental concentrations of estrone, 17beta-estradiol, estriol, and 17alpha-ethinylestradiol were treated. Liquid chromatography-mass spectrometry analysis demonstrated that the studied steroid estrogens were completely oxidized in the wastewater reaction mixture after a 1-h treatment with either HRP (8-10 U ml(-1)) or laccase (20 U ml(-1)). Using the recombinant yeast assay, it was also confirmed that both enzymatic treatments were very efficient in removing the estrogenic activity of the studied steroid estrogens. The laccase-catalyzed process seemed to present great advantages over the HRP-catalyzed system for up-scale applications for the treatment of municipal wastewater.

Quantification of steroid sex hormones using solid-phase extraction followed by liquid chromatography-mass spectrometry.

In this study, the occurrence of trace amounts of natural and synthetic steroid estrogens in the aquatic environment was studied using liquid chromatography coupled with electrospray mass spectrometry, following solid-phase extraction (SPE). The SPE was performed with C18 and NH2 cartridges. The first objective was to develop a reliable method for analyzing steroid estrogens (resulting from human and animal excretions) in different matrices. The method developed was then applied to quantify the occurrence of natural and synthetic hormones (estrone [E1], 17beta-estradiol [betaE2], 17alpha-estradiol [alphaE2], estriol [E3], and 17alpha-ethinylestradiol [EE2]) in environmental samples in surface water and wastewater treatment plant (WWTP) influent and effluent. In the WWTP influents, betaE2, alphaE2, and E3 were identified as ranging up to 72.6 ng/L in WWTP influent and to 16 ng/L in WWTP effluent. Analysis o f surface wa ter sampled upstream from the WWTP revealed the presence of all five estrogens, at levels up to 19.8 ng/L. These concentrations of estrogens pose an issue for large and small communities, because they are higher than the recommended guidelines for estrogen-active compounds and because a lot of communities use surface water as drinking-water sources.

Laccase-catalyzed conversion of natural and synthetic hormones from a municipal wastewater.

The Trametes versicolor-derived laccase-catalyzed oxidation of natural estrogens (estrone--E1; 17beta-estradiol--E2; and estriol--E3) and a synthetic estrogen (17alpha-ethinylestradiol--EE2) was studied in synthetic water and municipal wastewater to optimize the process for steroid estrogen removal in wastewater. The optimal pH for each studied steroid estrogen oxidation was approximately 6 in synthetic water. This research also focused on the wastewater matrix effect on developed enzymatic treatment. At pH 7.0 and 25+/-1 degrees C, the experiments showed that the laccase-catalyzed system for the removal of steroid estrogens was not significantly affected by the municipal wastewater matrix. Laccase activity of 20 U/ml was sufficient to achieve complete removal of studied steroid estrogens in both synthetic water and municipal wastewater. Moreover, 1-hydroxy-benzotriazole, when used as a mediator, improved laccase-catalyzed system efficiency, thus decreasing the overall cost of the enzymatic system.

Oxidation of natural and synthetic hormones by the horseradish peroxidase enzyme in wastewater.

Steroid estrogens, including both natural estrogens (e.g., estrone - E1; 17beta-estradiol - E2; and estriol - E3) and synthetic estrogens (e.g., 17alpha-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.

Natural and synthetic hormone removal using the horseradish peroxidase enzyme: temperature and pH effects.

The primary objective of our research was to establish the technical feasibility of using the horseradish peroxidase (HRP) enzyme for natural and synthetic estrogens-estrone (E1), 17beta-estradiol (E2), estriol (E3), and 17alpha-ethinylestradiol (EE2)-removal. The effects of temperature and pH on enzymatic treatment kinetics were investigated. Residual estrogen concentrations were quantified by liquid chromatography, coupled with mass spectrometry analysis. In a synthetic solution at pH 7 and 25+/-1 degrees C, the HRP enzyme-catalyzed process was capable of achieving 92-100% removal of E1, E2, E3, and EE2 within 1h of treatment with an HRP activity of 0.017 U/ml. The influence of the pH (5-9) and temperature (5-35 degrees C) on estrogen removal was observed to be significant, with the optimum pH near neutral conditions. The results also showed that wastewater constituents significantly impact the HRP-catalyzed estrogen removal. The experimental research proved that the HRP-catalyzed system is technically feasible for the removal of the main estrogens present in the environment at low concentrations.