Removal Of Estrogenic Activity Research Articles

Initial photocatalytic degradation intermediates/pathways of 17α-ethynylestradiol: Effect of pH and methanol

This study investigated the photocatalytic degradation of the synthetic oral contraceptive 17α-ethynylestradiol (EE2). Particular attention was paid on the effects of pH and the co-solvent methanol on the degradation intermediates of EE2. Twelve intermediates were identified, and several intermediates reported herein have not been found in previous studies. The degradation efficiency of EE2 and the number of identified intermediates decreased evidently at pH 3 and in the presence of methanol at pH 7. Three photocatalytic degradation pathways were proposed: The transformation of the phenolic moiety (pathway I) is the primary initial reaction pathway; the initial photocatalytic degradation in the aliphatic carbon linked to the aromatic ring (pathway II) only took place at pH 7; the isomerization of EE2 (pathway III) could occur only in the presence of methanol at pH 7. Results from this study underscore the importance of photocatalytic degradation on the removal of estrogenic activity mainly expressed by the phenol moiety of EE2.

Toxication or detoxication? In vivo toxicity assessment of ozonation as advanced wastewater treatment with the rainbow trout

Ozonation as advanced wastewater treatment method is an effective technique for micropollutant removal. However, the application of this method carries the inherent danger to produce toxic oxidation byproducts. For an ecotoxicological assessment conventionally treated wastewater, wastewater after ozonation and ozonated wastewater after sand filtration were evaluated in parallel at an operating treatment plant via the fish early life stage toxicity test (FELST) using rainbow trout ( Oncorhynchus mykiss). The FELST revealed a considerable developmental retardation of test organisms exposed to ozonated WW. This was accompanied by a significant decrease in body weight and length compared to reference water, to the conventionally treated WW and to the ozonated water after sand filtration. Hence sand filtration obviously prevents from adverse ecotoxicological effects of ozonation. An additional test with yolk-sac larvae resulted in a significant reduction of vitellogenin levels in fish exposed to ozonated wastewater compared to fish reared in conventionally treated wastewater. This demonstrates the effective removal of estrogenic activity by ozonation. Adverse ozonation effects may have been a result of the conversion of chemicals into more toxic metabolites. However, sand filtration reduced toxication effects indicating that these oxidation byproducts are readily degradable or adsorbable. The results indicate that in any case ozonation should not be applied without subsequent post treatment appropriate for oxidation byproducts removal (e.g. sand filtration).

Comparison of Trace Organics and Estrogenic Activity Removal in Integrated Fixed Film Activated Sludge and Conventional Wastewater Treatment

Comparison of Trace Organics and Estrogenic Activity Removal in Integrated Fixed Film Activated Sludge and Conventional Wastewater Treatment

Removal of estrogenic activity of iso-butylparaben and n-butylparaben by laccase in the presence of 1-hydroxybenzotriazole

In the presence of a redox mediator, 1-hydroxybenzotriazole (HBT), iso-butylparaben (iso-BP) and n-butylparaben (n-BP) were treated with laccase from white rot fungus Trametes versicolor. HPLC analysis demonstrated that iso-BP and n-BP almost completely disappeared from the reaction mixture after 4 h of treatment with the laccase-HBT system. Using the yeast two-hybrid assay system, it was also confirmed that the laccase-HBT system substantially removed the estrogenic activity of iso-BP and n-BP after 4 h of treatment. Furthermore, there was a linear relationship between the removal of estrogenic activity of both parabens and the decrease in their concentrations. These results demonstrate that the laccase-HBT system is effective in eliminating iso-BP and n-BP, and removing the estrogenic activity of both parabens.

Degradation and estrogenic activity removal of 17β-estradiol and 17α-ethinylestradiol by ozonation and O 3/H 2O 2

This work investigated the degradation of a natural (17β-estradiol) and a synthetic (17α-ethinylestradiol) estrogens (pure or in the mixture) and the removal of estrogenic activity by the ozonation and O 3/H 2O 2 process in three different pHs (3, 7 and 11). The effect of oxidation via OH radical was evaluated adding a radical scavenger (t-butanol) in the medium. Estrogenic activity was performed using the YES assay. 17β-estradiol and 17α-ethinylestradiol presented similar estrogenic potential and the association of these estrogens resulted in an addictive effect for estrogenic activity. Ozonation and O 3/H 2O 2 processes were effective in removing the estrogens in aqueous solution. In the mixture at pH 11, removals were higher than 98% and 96% for 17β-estradiol and 17α-ethinylestradiol, respectively. In pH 3, 17β-estradiol and 17α-ethinylestradiol removals were 100% and 99.7%, respectively. When estrogens were treated separately, the removals in pH 11 were superior to 99.7 and 98.8%, while in pH 3 were 100% and 99.5% for 17β-estradiol and 17α-ethinylestradiol, respectively. 17α-ethinylestradiol has been always removed at lower rates (pure or in the mixture) for all applied conditions. Estrogenic activity was completely removed in pH 3 for ozonation or O 3/H 2O 2. The samples oxidized in pH 11 presented higher estrogenic activity than those in pH 7. Estrogens removal was lower at pHs 7 and 11, when the scavenger was added to the media. The higher estrogen residual concentrations found in ozonation in presence of tert-butanol are contributing for higher estrogenic activity observed in pHs 7 and 11. By-products with estrogenic activity were formed by oxidation via OH radical. Only a few compounds could be identified in pHs 7 and 11 and they have a phenolic ring, which, probably is contributing to the estrogenic activity observed.

Treatment of swine wastewater by submerged membrane bioreactors with consideration of estrogenic activity removal

A model laboratory scale membrane bioreactor (MBR) for the treatment of swine wastewater has been studied to illustrate the removal mechanisms of selected endocrine disrupting compounds (EDCs). A pilot scale MBR was also operated to confirm the results from the laboratory scale study. Liquid extraction with cyclohexane followed by yeast estrogen screen (YES) assay was used to determine the estrogenic activity (EA) of wastewater and sludge samples. Both laboratory and pilot scale MBRs were demonstrated to be effective systems for EA removal from swine wastewater. The average removal rate was 93.5% in terms of EA in the soluble phase of swine wastewater, and 94.5% in terms of total EA. During the steady-state operation period total COD removal efficiencies ranged from 68.5% to 82.7% and up to 99.9% removal of NH 3-N was achieved with proper pH control. A model mass balance revealed that over 85% of the influent EA was reduced through MBR process by degradation or evaporation. An average of 9.4% of the influent EA was removed from the MBR system in the wasted sludge, whereas 5.4% of the EA in the influent was found in the treated effluent.

Enhanced expression of laccase during the degradation of endocrine disrupting chemicals in Trametes versicolor

A putative laccase cDNA from a white-rot basidiomycete, Trametes versicolor, that consisted of 1,769 nucleotides was cloned using the rapid amplification of cDNA ends (RACE)-PCR method. The deduced amino acid sequence had 4 putative copper binding regions, which are common to fungal laccases. In addition, the sequence was 57-97% homologous to sequences of other T. versicolor laccases. Additionally, the expression of laccase and manganese peroxidase in this fungus were both greatly increased under degrading conditions for bisphenol A, nonylphenol and two phthalic esters (benzylbutylphthalate and diethylphthalate), all of which are reportedly endocrine disrupting chemicals (EDCs). Furthermore, the estrogenic activities of the EDCs also decreased rapidly during incubation when examined in a two-hybrid yeast system. Finally, kojic acid inhibited the removal of estrogenic activities generated by bisphenol A and nonylphenol, which confirmed that laccase was involved in the degradation of EDCs in T. versicolor.

Removal of estrogenic activity from endocrine-disrupting chemicals by purified laccase ofPhlebia tremellosa

A white-rot basidiomycete, Phlebia tremellosa, produced a laccase that showed increased activity during degradation of phthalates. A laccase was purified through the ion exchange chromatography and preparative gel electrophoresis, and the estimated molecular weight was 75 kDa. The optimum pH and temperature of the purified laccase was pH 4.0 and 20 degrees C, respectively. The K(m) value of the enzyme was 55.7 microM, and the V(max) was 0.0541 OD min(-1) U(-1) for o-tolidine. Purified laccase reduced the estrogenic activity of four different endocrine-disrupting chemicals. However, this effect was reduced by a laccase inhibitor, kojic acid, which confirmed that the laccase was involved in the removal of estrogenic activity.

Efficient Removal of Estrogenic Activity during Oxidative Treatment of Waters Containing Steroid Estrogens

The discharge of synthetic and natural steroid estrogens from municipal wastewaters to the aquatic environment has received increased attention because of their potential reproductive effects on fish. Using 17alpha-ethinylestradiol (EE2) as a representative steroid estrogen, several oxidants applied in wastewater treatment (chlorine, bromine, ozone, hydroxyl radical, chlorine dioxide, and ferrate) were shown to selectively and rapidly transform EE2. For typically applied oxidant doses, these transformations occur in the time range of seconds to minutes. The resulting initial transformation products of EE2 exhibit a substantially lower in vitro estrogenic activity (< 13% of EE2). For selected structural derivatives of EE2, a quantitative structure-activity relationship was established between substituents changed on the phenolic moiety and the relative in vitro estrogenic activity. In addition, the initial EE2 transformation products that still exhibit residual estrogenic activity are quickly further transformed by most of the tested oxidants. Therefore, oxidative wastewater treatment may serve as a powerful tool to remove estrogenic activity induced by steroid estrogens.

Removal of natural and xeno-estrogens during conventional wastewater treatment

The ecological impacts of natural estrogens and xenoestrogens in treated wastewater include altered sexual development and sex ratios among continuously exposed organisms. The primary sources of estrogenic activity in wastewater are natural estrogens such as estrone, 17β-estradiol and estriol and synthetic compounds like 17α-ethinylestradiol, alkylphenols and alklphenol ethoxylates. Precursors in raw wastewater can yield estrogenic intermediates during wastewater treatment. All these compounds can be destroyed by biochemical processes, albeit at significantly different rates or under different conditions. That is, estrogenic compounds can be, but are not always, destroyed by conventional wastewater treatment processes, suggesting that conventional processes can be optimized for removal of estrogenic activity from wastewater. Sorption to sludges derived from wastewater treatment affects the fates of hydrophobic xenoestrogens such as nonylphenol, in part because the biodegradability of sorbed contaminants is limited. It may also be possible to tailor sludge stabilization processes to remove trace contaminants, including estrogens. For example, there are significant differences in the efficiencies of aerobic and anaerobic digestion for destruction of alkylphenols and probably other estrogenic compounds with aromatic moieties. Because advanced wastewater treatment is not economically feasible for most communities, there is ample incentive to develop accurate relationships between operational parameters and removal of estrogenic compounds during secondary wastewater treatment.

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, 17β-estradiol, estriol, and 17α-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.

Estrogenic activity removal of 17β-estradiol by ozonation and identification of by-products

This work investigated the degradation of a natural estrogen (17β-estradiol) and the removal of estrogenic activity by the ozonation process in three different pHs (3, 7 and 11). A recombinant yeast assay (YES assay) was employed to determine estrogenic activity of the ozonized samples and of the by-products formed during the ozonation. Ozonation was very efficient for the removal of 17β-estradiol in aqueous solutions. High removals (>99%) were achieved with low ozone dosages in the three different pHs. Several by-products were formed during the ozonation of 17β-estradiol. However, only a few compounds could be identified and confirmed. Different by-products are formed at different pHs, which is probably due to different chemical pathways and different oxidants (O 3 and OH radical). The by-products formed at pH 11 were 10 ε-17β-dihydroxy-1, 4-estradieno-3-one (DEO) and 2-hydroxyestradiol, which were not formed in pH 3. Only testosterone could be observed in pH 3, whereas at pH 7 all three by-products were found. At pH 7 and 11 the applied ozone dosages were not enough to remove all the estrogenicity from samples, even though the 17β-estradiol residual concentration for these two pHs was lower than at pH 3. Higher estrogenicity was detected at pH 11. An explanation to this fact may be that oxidation via OH radical forms more by-products with estrogenic activity. Probably, the formation of 2-hydroxyestradiol at pHs 7 and 11 is contributing to the residual estrogenicity of samples ozonized at these pHs. In this work, complete removal of estrogenic activity was only obtained at pH 3.

Removal of estrogenic activity of 4‐tert‐octylphenol by ligninolytic enzymes from white rot fungi

4-tert-Octylphenol (4-t-OP) was treated with the white rot fungus Phanerochaete sordida YK-624 under ligninolytic condition with low-nitrogen and high-carbon culture medium. 4-t-OP completely disappeared after 5 days of treatment and the activities of ligninolytic enzymes, laccase and manganese peroxidase (MnP), were detected during this period, thus suggesting that the disappearance of 4-t-OP is related to these extracellular enzymes. Therefore, 4-t-OP was treated with laccase and MnP prepared from white rot fungi cultures. HPLC analysis demonstrated that 4-t-OP completely disappeared in the reaction mixture after 1 h of treatment with either laccase or MnP. Using the yeast two-hybrid assay system, it was also confirmed that laccase and MnP substantially removed the estrogenic activity of 4-t-OP after 1 and 2 h of treatment, respectively. These results strongly demonstrate that ligninolytic enzymes are effective in removing the estrogenic activity of 4-t-OP.

Destruction of estrogenic activity in water using UV advanced oxidation

The transformation of the steroidal Endocrine Disrupting Compounds (EDCs), 17-beta-estradiol (E2) and 17-alpha-ethinyl estradiol (EE2) by direct UV photolysis and UV/H(2)O(2) advanced oxidation was studied from the perspective of the removal of estrogenic activity associated with the compounds. First, experiments were performed to link the oxidation of E2 and EE2 with subsequent reduction in estrogenic activity. No statistically significant difference between removal rates was observed, implying that the oxidation products of E2 and EE2 are not as estrogenic (measured by the Yeast Estrogen Screen (YES)) as the parent compounds. Utilizing the YES, 90% removal of estrogenic activity of E2 and EE2 at environmentally relevant concentrations ( approximately 3 microg L(-1)) was achieved using a combination of 5 mg L(-1) H(2)O(2) and a UV fluence of less than 350 mJ cm(-2). Thus, these compounds, when considered at environmentally relevant levels, are significantly degraded at much lower UV fluences than previously thought. A steady state OH radical model was used to predict oxidation of EE2 in laboratory and natural waters.

The removal of estrogenic activity and control of brominated by-products during ozonation of secondary effluents

The purposes of this study were to investigate the behavior of brominated by-products, such as bromate ion and total organic bromide, formed during ozonation for the removal of estrogenic activity in sewage effluents and to propose operation parameters for the ozonation process. It is necessary to reduce the E 2 equivalent concentration of estrogenic activity in secondary effluent treated by 90% of the initial one. To do so, ozonation until dissolved ozone concentration increased to 0.1 mg/L (which corresponds to approximately 1 mg O 3/mg DOC 0 [consumed ozone per initial DOC] of consumed ozone for the effluent in this study) is proposed as an operation parameter for ozonation without the formation of brominated by-products.

Occurrence of Estrogenic Compounds in and Removal by a Swine Farm Waste Treatment Plant

The total estrogenic activity of the wastewater from a swine farm in Japan was quantitatively characterized, and the compounds responsible for the estrogenic activity were identified and quantified. The wastewater treatment process consisted of a series of an up-flow anaerobic sludge blanket (UASB) and a trickling filter. Samples were collected at each treatment step, and the total estrogenic activity was determined by use of an in vitro gene expression assay (MVLN; MCF-7 human breast cancer cell stably transfected with the pVit-tk-LUC receptor plasmid). Individual estrogenic compounds were identified and quantified using liquid chromatography-mass spectrometry (LC/MS) and liquid chromatography-tandem mass spectrometry (LC/ MS/MS). To further identify the compounds contributing to the estrogenic activity in the wastewater, the sample extracts were fractionated into 12 fractions (fractions 1-12) by HPLC. The rate of removal of estrogenic activity between the effluent and the influent was greater than 97%. The trickling filter removed the majority of the estrogenic activity. The removal rates of specific estrogenic compounds ranged from 44 to 99%. Estrogenic activity was detected mainly in the fractions containing estrone (El), 17beta-estradiol (betaE2), 17alpha-estradiol (alpha E2), estriol (E3), bisphenol A (alphaPA), and equol (EQ0). The ratios of betaE2-EQc (betaE2 equivalents derived from chemical analysis) to betaE2-EQB (betaE2 equivalent derived from bioassay) in the 12 fractions collectively were contributed by El (17-30%), betaE2 (23-30%), acE2 (<1%), E3 (1-2%), BPA (<1%), and EQO (2-3%) in the influent and El (16-37%), PE2 (<1-7%), alphaE2 (<1%), E3 (<1-3%), BPA (<1%), and EQO (<1%) in the effluent. The compounds responsible for most of the estrogenic activity measured in the bioassay were natural estrogens such as El and betaE2.

Removal of estrogenic activity of natural steroidal hormone estrone by ligninolytic enzymes from white rot fungi

Natural steroidal hormone estrone (E 1) was treated with the white rot fungus Phanerochaete sordida YK-624 under ligninolytic condition with low-nitrogen and high-carbon culture medium. E 1 decreased by 98% after 5 d of treatment and the activities of ligninolytic enzymes, manganese peroxidase (MnP) and laccase, were detected during treatment, which suggested that the disappearance of E 1 is related to ligninolytic enzymes produced extracellularly by white rot fungus. Therefore, E 1 was treated with MnP and laccase prepared from the culture of white rot fungi. HPLC analysis demonstrated that E 1 disappeared completely in the reaction mixture after 1 h of treatment with either MnP or laccase. Using the yeast two-hybrid assay system, it was also confirmed that both enzymatic treatments completely removed the estrogenic activity of E 1 after 2 h. These results strongly suggest that ligninolytic enzymes are effective in removing the estrogenic activity of E 1.

Removal of estrogenic activity of endocrine-disrupting genistein by ligninolytic enzymes from white rot fungi

Endocrine-disrupting genistein was treated with the white rot fungus Phanerochaete sordida YK-624 under ligninolytic condition with low-nitrogen and high-carbon culture medium. Genistein decreased by 93% after 4 days of treatment and the activities of ligninolytic enzymes, manganese peroxidase (MnP) and laccase, were detected during treatment, thus suggesting that the disappearance of genistein is related to ligninolytic enzymes produced extracellularly by white rot fungi. Therefore, genistein was treated with MnP, laccase, and the laccase-mediator system with 1-hydroxybenzotriazole (HBT) as a mediator. HPLC analysis demonstrated that genistein disappeared almost completely in the reaction mixture after 4 h of treatment with either MnP, laccase, or the laccase–HBT system. Using the yeast two-hybrid assay system, it was also confirmed that three enzymatic treatments completely removed the estrogenic activity of genistein after 4 h. These results strongly suggest that ligninolytic enzymes are effective in removing the estrogenic activity of genistein.

Removal of Estrogenic Activity and Formation of Oxidation Products during Ozonation of 17α-Ethinylestradiol

This study investigated the oxidation of the oral contraceptive 17alpha-ethinylestradiol (EE2) during ozonation. First, the effect of ozone (O3) on the estrogenic activity of aqueous solutions of EE2 was studied using a yeast estrogen screen (YES). It could be shown that O3 doses typically applied for the disinfection of drinking waters were sufficient to reduce estrogenicity by a factor of more than 200. However, it proved impossible to completely remove estrogenic activity due to the slow reappearance of 0.1-0.2% of the initial EE2 concentration after ozonation. Second, oxidation products formed during ozonation of EE2 were identified with LC-MS/MS and GC/MS and the help of the model compounds 5,6,7,8-tetrahydro-2-naphthol (THN) and 1-ethinyl-1-cyclohexanol (ECH), which represent the reactive phenolic moiety and the ethinyl group of EE2. Additionally, oxidation products of the natural steroid hormones 17beta-estradiol (E2) and estrone (E1) were identified. The chemical structures of the oxidation products were significantly altered as compared to the parent compounds, explaining the diminished estrogenic activity after ozonation. Overall,the results demonstrate that ozonation is a promising tool for the control of EE2, E2, and E1 in drinking water and wastewater.

Rapid loss of estrogenicity of steroid estrogens by UVA photolysis and photocatalysis over an immobilised titanium dioxide catalyst

The presence of low levels of natural and synthetic steroid estrogens in the aquatic environment, and their biological effects on aquatic organisms, are presently issues of concern. In this study, we investigated the temporal removal of estrogenic activity of several potent and environmentally relevant steroid estrogens by photocatalysis over an immobilised titanium dioxide (TiO 2) catalyst. We used a recombinant yeast assay to measure estrogenic activity, which provided detection limits within the reactor of 53 ng/l for 17 β-estradiol and 17 α-ethinylestradiol, and 100 ng/l for estrone. Pseudo-first-order kinetic data showed that photocatalysis over titanium dioxide was equally effective at removing the estrogenic activity of all three steroid substrates in aqueous solutions (initial concentrations of 10 μg/l) with a 50% reduction in estrogenicity within 10 min. In control experiments without TiO 2 catalyst, the rate of UVA photolysis of the steroid substrates varied, but was most effective with 17 α-ethinylestradiol followed by estrone, and was least effective with 17 β-estradiol (0.42, 0.2 and <0.1 times the rate achieved with photocatalysis, respectively). The application of photocatalysis for the removal of steroid compounds within STW effluent released into the aquatic environment is discussed.