Sorption and desorption of three endocrine disrupters in soils

Sorption of the estrogens estrone (E1), 17beta-estradiol (E2) and 17alpha-ethynylestradiol (EE2) on four soils was examined using batch equilibrium experiments with initial estrogen concentrations ranging from 10 to 1000 ng mL-1. At all concentrations, >85% of the three estrogens sorbed rapidly to a sandy soil. E1 sorbed more strongly to soil than E2 or EE2. Partial oxidation of E2 to E1 was observed in the presence of soils. Autoclaving was more effective at reducing this conversion than inhibition with sodium azide or mercuric chloride, and had little effect on sorption, relative to the chemical microbial inhibitors. Sorption of EE2 was greater for fine-textured than coarse-textured soils, but greater than 90% of EE2 sorbed onto all four soils. The greatest degree of desorption of estrogens from the sandy soil occurred with the lowest initial concentration of 10 ng mL-1 and reached levels >or=80% for E1 and E2. Desorption of EE2 was greater in coarser textured soils than finer-textured soils. Again, relative desorption from all soils was greatest with low initial concentrations. Therefore, at environmentally relevant concentrations, estrogens quickly sorb to soils, and soils have a large capacity to bind estrogens, but these endocrine-disrupting compounds can become easily desorbed and released into the aqueous phase.     

Identification and behavior of reaction products formed by chlorination of ethynylestradiol

Six products were formed by reaction of ethynylestradiol (EE2) with sodium hypochlorite in buffered solutions. 4-Chloroethynylestradiol (4-ClEE2) and 2,4-dichloroethynylestradiol (2,4-diClEE2) were identified as the two major reaction products, using preparative HPLC, MS, and NMR. When EE2 reacted with chlorine at different pHs (pH 5, 7, and 9) or chlorine concentrations (0.2, 1, 2, and 5 mmol/l, corresponding to molar ratios to EE2, 1, 5, 10, and 25, respectively), the formation of 4-ClEE2 and 2,4-diClEE2 was observed under the above conditions, and the highest yields were 20 and 52 mol%, respectively. EE2 was consumed almost completely within 5 min of chlorination by addition of chlorine of more than 1 mmol/l (molar ratio to EE2, 5). On the other hand, the two products existed in highly chlorinated solutions after 60 min (4ClEE2, 1-6 mol%; 2,4-diClEE2, 3-25 mol%). The estrogenic activities of 4-ClEE2 by estrogen receptor alpha or beta binding assay were similar to those of the parent EE2, and the activities of 2,4-diClEE2 were lower about 10 times.     

Isolation and identification of 3-bromocarbazole-degrading bacteria

In this study, a bacterial strain, CH-1, capable of degrading 3-bromocarbazole (3-BCZ) was isolated from a polluted soil. Based on its physio-biochemical characteristics and 16S rRNA genes, strain CH-1 was identified as a Stenotrophomonas sp. Strain CH-1 was able to degrade 70% of 50 mg/L 3-BCZ within 8 d at pH 7.0 and 30°C in mineral salt medium (MSM). During the process, the main intermediate metabolite was identified as (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2, 4-dienoic by gas (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2,4-dienoic via gas chromatograph-mass spectrometry (GC-MS) analysis. The metabolite disappeared after 14 d, suggesting that the metabolite can also be degraded by strain CH-1. 3-BCZ is a new persistent organic pollutant. This is the first report of the biodegradation of 3-BCZ. The results indicated that strain CH-1 may be a promising bacterial candidate for the bioremediation of environments polluted with polyhalogenated carbazoles (PHCs).     

Sorption and Desorption of Three Endocrine Disrupters in Soils

Sorption of the estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) on four soils was examined using batch equilibrium experiments with initial estrogen concentrations ranging from 10 to 1000 ng mL^?1. At all concentrations, >85% of the three estrogens sorbed rapidly to a sandy soil. E1 sorbed more strongly to soil than E2 or EE2. Partial oxidation of E2 to E1 was observed in the presence of soils. Autoclaving was more effective at reducing this conversion than inhibition with sodium azide or mercuric chloride, and had little effect on sorption, relative to the chemical microbial inhibitors. Sorption of EE2 was greater for fine-textured than coarse-textured soils, but greater than 90% of EE2 sorbed onto all four soils. The greatest degree of desorption of estrogens from the sandy soil occurred with the lowest initial concentration of 10 ng mL^?1 and reached levels ≥80% for E1 and E2. Desorption of EE2 was greater in coarser textured soils than finer-textured soils. Again, relative desorption from all soils was greatest with low initial concentrations. Therefore, at environmentally relevant concentrations, estrogens quickly sorb to soils, and soils have a large capacity to bind estrogens, but these endocrine-disrupting compounds can become easily desorbed and released into the aqueous phase.     

Factors controlling the biodegradation of 17beta-estradiol, estrone and 17alpha-ethinylestradiol in different natural soils

We conducted a series of laboratory microcosm incubations with [(14)C]-labeled 17beta-estradiol (E2), estrone (E1) and 17alpha-ethinylestradiol (EE2) in 17 different natural soils to characterize hormone mineralization. A significantly higher mineralization was observed for E1 (2.0-37.6%) and E2 (4.2-50.2%) than for EE2 (0.5-2.6%) in all test soils after 21 days. Soil physical or chemical parameters were not related to estrogen mineralization. Although sorption parameters varied greatly for E2 (K(F)=21.9-317.5 mL g(-1)), for E1 (K(F)=46.0-517.5 mL g(-1)) and for EE2 (K(F)=29.9-326.1 mL g(-1)) this apparently did not control estrogen bioavailability since it showed no effects on hormone mineralization. In order to elucidate the controlling factors, experiments with combined additions of radiolabeled estrogens and different substrates were conducted. Additions of ammonium nitrate or alanine to soil samples generally increased EE2 mineralization, thus indicating N-limitation. Additions of glucose induced higher E2 and EE2 degradation in comparison to control samples which is attributed to co-metabolism. Additions of saw dust, catechol or streptomycin influenced the microbial population in the test soils and affected the mineralization of E2 and EE2. Thus, we clearly demonstrate that different microbial communities are responsible for E2 and EE2 degradation in soils. We suggest that EE2 is mineralized by white-rot fungi and E2 by bacteria.     

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.     

Titanium dioxide mediated photocatalytic degradation of 17beta-estradiol in aqueous solution

Photocatalytic degradation of 17beta-estradiol (E2) in aqueous medium mediated with titanium dioxide (TiO(2)) was studied. Moreover, effect of TiO(2) dosage on the degradation efficiency was investigated. Particular attention was paid to the identification of intermediates and analysis of photocatalytic degradation mechanism of E2 under neutral and alkaline conditions. The degradation efficiency of E2 increased with increasing concentration of TiO(2) but decreased due to light scattering as TiO(2) concentration was greater than 0.5mgml(-1). Several intermediates were formed during photocatalytic degradation of E2. However, only a few of the compounds could be identified and confirmed by LC-MS and LC-MS/MS. Six intermediates were observed by photocatalytic oxidation under alkaline conditions, namely 2-hydroxyestradiol, 10epsilon-17beta-dihydroxy-1,4-estradien-3-one (DEO), 10epsilon-hydroperoxide-17beta-hydroxy-1,4-estradien-3-one and three kinds of dicarboxylic acids formed by the opening of aromatic ring. In addition to the six intermediates mentioned above, 17beta-hydroxy-1,4-estradien-3-one (EO) was observed under neutral conditions and in the presence of methanol. Based on these intermediates, which were hardly degraded even after E2 was fully degraded, the mechanism of E2 degradation by TiO(2) photocatalysis was elucidated.     

Removal of selected natural and synthetic estrogenic compounds in a Canadian full-scale municipal wastewater treatment plant.

The effect of a full-scale municipal wastewater treatment plant (WWTP) and each of the treatment units within the stream on the removal of endocrine-disrupting compounds was evaluated by tracking 17-beta-estradiol (E2), estrone (E1), and 17-alpha-ethinylestradiol (EE2). The overall performance of the WWTP compared well with other plants, as 90.5% removal of E1+E2 and 74.9% removal of EE2 were observed. A larger fraction of EE2 entered the plant in particulate form than E1 and E2, while a lower fraction of EE2 left the plant in particulate form than soluble form. The activated sludge units reduced the concentration of E1+E2 and EE2 in the liquid phase by 88.2% and 44.6%, respectively. The UV treatment process did not reduce the amount of estrogens. The aqueous phase of the tertiary lagoon solids contained higher levels of estrogens compared with the lagoon influent.     

Occurrence and photochemical degradation of 17alpha-ethinylestradiol in Acushnet River Estuary

17alpha-Ethinylestradiol (EE2), a major constituent of common contraceptive pills, and three other estrogenic hormones, estrone (E1), 17beta-estradiol (E2) and mestranol (MeEE2) have been determined in Acushnet River Estuary seawater using a GC-MS technique. Among three estrogenic compounds detected, EE2 has the highest concentration, up to 4.7 ng/l, at which EE2 may affect lobster and other fish abundance in the coastal seawater due to its high biological activity on fish feminization. Two natural estrogenic hormones, E1 and E2 have also been found in the estuary at concentrations up to 1.2 ng/l and 0.83 ng/l, respectively. Although EE2 is persistent to microbial degradation, it can undergo a rapid photodegradation in estuarine seawater under natural sunlight irradiation, with a half-life of less than 1.5 days in spring sunny days.     

Microbial degradation of 17β -estradiol and 17α -ethinylestradiol followed by a validated HPLC-DAD method

This work aimed at studying the biodegradation of two estrogens, 17α -estradiol (E2) and 17β -ethinylestradiol (EE2), and their potential metabolism to estrone (E1) by microbial consortia. The biodegradation studies were followed by High Performance Liquid Chromatography–Diode Array Detector (HPLC–DAD) using a specifically developed and validated method. Biodegradation studies of the estrogens (E2 and EE2) were carried out with activated sludge (consortium A, CA) obtained from a Wastewater Treatment Plant (WWTP) and with a microbial consortium able to degrade recalcitrant compounds, namely fluorobenzene (consortium B, CB). E2 was more extensively degraded than EE2 by CA whereas CB was only able to degrade E2. The addition of acetate as a supplementary carbon source led to a faster biodegradation of E2 and EE2. E1 was detected as a metabolite only during the degradation of E2. The 16S rRNA gene sequence analyses of strains recovered from the degrading cultures revealed the presence of the genera Pseudomonas, Chryseobacterium and Alcaligenes. The genera Pseudomonas and Chryseobacterium were retrieved from cultures supplied with E2 and EE2, while the genus Alcaligenes was found in the presence of E2, suggesting that they might be involved in the degradation of these compounds.     

β-Estradiol and ethinyl-estradiol contamination in the rivers of the Carpathian Basin

17β-Estradiol (E2) and 17α-ethinyl estradiol (EE2), which are environmental estrogens, have been determined with LC-MS in freshwater. Their sensitive analysis needs derivatization and therefore is very hard to achieve in multiresidue screening. We analyzed samples from all the large and some small rivers (River Danube, Drava, Mur, Sava, Tisza, and Zala) of the Carpathian Basin and from Lake Balaton. Freshwater was extracted on solid phase and derivatized using dansyl chloride. Separation was performed on a Kinetex XB-C18 column. Detection was achieved with a benchtop orbitrap mass spectrometer using targeted MS analysis for quantification. Limits of quantification were 0.05 ng/L (MS1) and 0.1 ng/L (MS/MS) for E2, and 0.001 ng/L (MS1) and 0.2 ng/L (MS/MS) for EE2. River samples contained n.d.–5.2 ng/L E2 and n.d.–0.68 ng/L EE2. Average levels of E2 and EE2 were 0.61 and 0.084 ng/L, respectively, in rivers, water courses, and Lake Balaton together, but not counting city canal water. EE2 was less abundant, but it was still present in almost all of the samples. In beach water samples from Lake Balaton, we measured 0.076–0.233 E2 and n.d.–0.133 EE2. A relative high amount of EE2 was found in river Zala (0.68 ng/L) and in Hévíz-Páhoki canal (0.52 ng/L), which are both in the catchment area of Lake Balaton (Hungary).     

How seasonality affects the flow of estrogens and their conjugates in one of Japan's most populous catchments

A detailed study of the free and conjugated estrogen load discharged by the eight major sewage treatment plants into the Yodo River basin, Japan was carried out. Sampling campaigns were focused on the winter and autumn seasons from 2005 to 2008 and the free estrogens estrone(E1), 17β-estradiol(E2), estriol(E3), 17α-ethynylestradiol(EE2) as well as their conjugated (sulfate and glucuronide) forms. For both sewage effluent and river water E2 and E1 concentrations were greatest during the winter period (December-March). This coincides with the period of lowest rainfall and lowest temperatures in Japan. E1 was the dominant estrogenic component in effluent (means of 10-50 ng/L) followed by E2 (means of 0.5-3 ng/L). The estrogen sulfate conjugates were found intermittently in the 0.5-1.7 ng/L concentration range in the sewage effluents. The greatest estrogen exposure was found to be in the Katsura River tributary which exceeded 1 ng/L E2-equivalents during the winter period.     

Assessment of the importance of sorption for steroid estrogens removal during activated sludge treatment

Distribution coefficients (K(d)) between water and activated sludge particles (f(oc)=27.7+/-0.1%) were measured for the steroid estrogens (SE), estrone (E1), 17beta-estradiol (E2) and 17alpha-ethinylestradiol (EE2) in batch experiments. Experimental concentration levels ranged from environmentally realistic low ng/l to the high microg/l. In this range K(d)s were independent of their water concentration. The experimentally obtained K(d)s (with 95% confidence intervals) were 402+/-126 l/kg, 476+/-192 l/kg and 584+/-136 l/kg for E1, E2 and EE2, respectively. K(d)s were used to estimate the fraction of the total SE concentration that is expected to be sorbed in the activated sludge treatment tanks of a typical STP assuming equilibrium conditions. Assuming a suspended solids concentration of 4 g/l dissolved solids (ds), it was estimated that 61+/-9%, 66+/-13% and 70+/-6% of the total concentration of E1, E2 and EE2, respectively, would be sorbed during activated sludge treatment. The fraction of the SEs that was expected to be sorbed to suspended sludge particles in the effluents from a typical Danish STP was estimated to be only 0.20+/-0.06%, 0.24+/-0.10% and 0.29+/-0.07% of the total concentration of E1, E2 and EE2, respectively, at a suspended solids concentration of 5 mg/lds. For a typical STP the removal of steroid estrogens with excess sludge was estimated to be only 1.5-1.8% of the total loading if equilibrium conditions exists. Sorption is therefore not important for the fate of SEs in STPs compared to biodegradation.     

17 β-estradiol and 17 α-ethinylestradiol mineralization in sewage sludge and biosolids

Natural steroid estrogens (e.g., 17 β-estradiol, E2), synthetic steroid estrogens (e.g., 17 α-ethinylestradiol, EE2) and pharmaceutical antibiotics (e.g., ciprofloxacin) are chemicals detected in biosolids and sewage sludges because they partition into the solids fraction during the wastewater treatment process. This research utilized a three-way factorial design (six media × two estrogens × three antibiotic treatments) to quantify cumulative E2 and EE2 mineralization over 133 d (MAX) in a range of sewage sludge and biosolid samples in the presence (4 and 40 mg kg^?1) and absence of ciprofloxacin. The same three-way factorial design was utilized to quantify the impact of the six media, E2 or EE2, and ciprofloxacin on cumulative soil respiration over 133 d (RESP). Minimal ciprofloxacin mineralization was observed (<0.05% over 133 d), but despite its persistence, ciprofloxacin had no significant effect on MAX of E2 or EE2, and, in general, no significant effect on RESP. MAX ranged from 38.38% to 48.44% for E2 but from only 0.72% to 24.27% for EE2 although RESP was relatively similar, ranging from 101.00 to 866.54 mg CO₂ in the presence of E2 and from 69.55 to 893.95 mg CO₂ in the presence of EE2. The sorption-limited bioavailability of EE2, which is inherently resistant to biodegradation due to chemical structure, as MAX and Freundlich sorption coefficients (K_f) were negatively correlated. As such, the K_f values of EE2 were largest in composted biosolids in which EE2 was particularly resistant to microbial degradation as the MAX of EE2 was <3%. In contrast, the MAX of E2 showed a positive association with the K_f values of E2 because some steps in the E2 transformation process have been found to occur in the sorbed phase. The MAX of E2 was significantly greater in the biosolid and composted biosolid media than in any other media, whereas the MAX of E2 decreased in the following order: secondary sewage sludge > primary sewage sludge > biosolid = composted biosolid. This suggests that sewage sludges in municipal lagoons and pre-treatment holding lagoons are a more favorable media for mineralization of EE2, whereas biosolids in post-treatment storage lagoons are a more favorable media for the mineralization of E2. The presence of ciprofloxacin will have no impact on the potential E2 or EE2 mineralization rates in these cases.     

Abiotic transformation of estrogens in synthetic municipal wastewater: An alternative for treatment?

The abiotic transformation of estrogens, including estrone (E1), estradiol (E2), estriol (E3) and ethinylestradiol (EE2), in the presence of model vegetable matter was confirmed in this study. Batch experiments were performed to model the catalytic conversion of E1, E2, E3 and EE2 in synthetic wastewater. Greater than 80% reduction in the parent compounds was achieved for each target chemical after 72 h with the remaining concentration distributed between aqueous and solid phases as follows: 13% and 7% for E1, 10% and 2% for E2, 6% and 2% for E3, and 8% and 3% for EE2, respectively. Testosterone, androstenedione and progesterone were also monitored in this study, and their concentrations were found to be in agreement with initially spiked amount. Data collected under laboratory conditions provided the basis for implementing new abiotic wastewater treatment technologies that use inexpensive materials.     

Degradation of chlorophenols in aqueous media using UV XeBr excilamp in a flow-through reactor

2-Chlorophenol (2-CP), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) at initial concentrations of 10, 20, 50 and 100mg l(-1) were degraded in aqueous media by direct UV photolysis using dielectric barrier discharge XeBr( *) excilamp (283nm) in a flow-through photoreactor. The pseudo-first order rate constants were highest and half-life times were lowest for 4-CP. The rates of photolysis under the experimental conditions increased in the order: 2-CP<2,4-DCP<4-CP. The intermediates of photolysis were identified by GC-MS and HPLC. The evolution of hydroquinone and p-benzoquinone as major intermediates of 4-CP photolysis was monitored.     

The role of organic ligands in ferrous-induced photochemical degradation of 2,4-dichlorophenoxyacetic acid

Recent studies have shown that hydrogen peroxide is generated in a ferrioxalate-induced photoreductive reaction, but information about the effect of organic ligands on the photochemical behaviour of ferrous species is limited. The degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) by a ferrous-catalyzed oxidation in the presence of various ligands such as formate, citrate, malelate, oxalate, and ethylenediaminetetra-acetic acid (EDTA) was studied. The experiments were conducted under either dark or irradiated (350n m) conditions. Forty-two percent and 34% of 2,4-D were removed by the Fe(2+)/oxalate/UV and Fe(2+)/citrate/UV processes, respectively, after 30 min of reaction and oxidative intermediates were obtained in both cases. The presence of hydroxylated intermediates suggests that 2,4-D may be attacked by hydroxyl radicals, which are the products of the photo-Fenton-like reaction. As such, hydrogen peroxide was produced by the photolysis of ferrous oxalate or ferrous citrate, referred to hereafter as photogenerated H(2)O(2). As expected, the total removal percentage of 2,4-D jumped to 97% when 1mM of hydrogen peroxide (so-called spiked H(2)O(2)) was externally added to the reaction vessel to initiate the Fe(2+)/oxalate/UV process. Therefore, the treatment of 2,4-D by the Fe(2+)/oxalate/H(2)O(2)/UV system can be operated in two steps: the photolysis of ferrous oxalate first, followed by adding the spiked H(2)O(2) sometime after the commencement of the reaction. A two-phase model has been developed to describe this tandem ferrous-catalyzed photooxidation, which would help to achieve the mineralization of 2,4-D.     

Presence of diclofenac,estradiol, and ethinylestradiol in Manzanares River (Spain) and their toxicity to zebrafish embryo development

Environmental Science and Pollution Research - Diclofenac (DCF), 17-β-estradiol (E2), and 17-α-ethinylestradiol (EE2) are emerging pollutants included in the first watch list agreed by...