Anaerobic transformation kinetics and mechanism of steroid estrogenic hormones in dairy lagoon water

Wastewater from concentrated animal feeding operations (CAFOs) frequently contains high concentrations of steroid estrogenic hormones. Release of these hormones into the environment may occur when CAFO wastewater is applied to agricultural lands as a nutrient and water source for crop production. To assess the potential risk of hormone contaminants derived from animal wastewater, we investigated the transformation kinetics and mechanisms of three natural estrogenic hormones (17α-estradiol, 17β-estradiol, and estrone) in aqueous solutions blended with dairy lagoon water under anaerobic conditions. Initial transformations of the three hormones in the dairy lagoon water were dominated by biodegradation and the degradation rates were temperature-dependent. The total amounts of hormones (initial concentration at 5 mg L(-1)) remaining in the solution after 52 days at 35 °C accounted for approximately 85%, 78%, and 77% of the initial amounts of 17α-estradiol, 17β-estradiol, and estrone, respectively. This observation suggests that these hormones are relatively stable over time and may accumulate in anaerobic or anoxic environments and anaerobic CAFO lagoons. A racemization reaction between 17α-estradiol and 17β-estradiol via estrone was observed in aqueous solutions in the presence of CAFO wastewater under anaerobic conditions. The initial hormone concentrations did not affect this degradation mechanism. A reversible reaction kinetic model was applied to fit the observed transformation dynamics. The degradation and regeneration of the parent hormone and its metabolites were successfully simulated by this model. The information in this study is useful for assessing the environmental risk of steroid hormones released from CAFO wastewater and to better understand why these hormone contaminants persist in many aquatic environments.     

Analysis of steroid hormones in a typical dairy waste disposal system

The environmental loading of steroid hormones contained in dairy wastes may cause an adverse effect on aquatic species. To better assess the potential risks of hormone contamination resulting from land application of dairy wastes, various steroid hormones were determined in a typical dairy waste disposal system. Quantitative methods using gas chromatography/mass spectrometry (GC/MS) were developed to monitor low levels of steroid hormones in complex solid and liquid samples contaminated with dairy manure. The preparation method for wastewater analysis consisted of solid-phase extraction and purification steps, which minimized interference from the sample matrices and achieved low detection limits for the studied hormones. In the dairy wastewater and lagoon water, three endogenous hormones-17alpha-estradiol, 17beta-estradiol, and estrone-were detected. The concentration of 17alpha-estradiol in fresh milk parlor effluent rapidly decreased along the wastewater disposal route, whereas the concentration of estrone increased along this same pathway. This suggests that 17alpha-estradiol was readily oxidized to the metabolite estrone. Levels of total steroid hormones in the sequencing lagoon water were approximately 1-3 orders of magnitude lower than those in the fresh dairy wastewaters, indicating significant removal of these hormones during the transport of dairy wastewater from source to field. In solid dairy waste samples, four steroid hormones were identified and quantified. Increasing the piling time of solid wastes and increasing the residence time of wastewater in sequencing lagoons are suggested to be economical and efficient agriculture practices to extend the degradation time of hormone contaminants and thereby reduce the hormone load to the environment.     

Comprehensive bench- and pilot-scale investigation of trace organic compounds rejection by forward osmosis

Forward osmosis (FO) is a membrane separation technology that has been studied in recent years for application in water treatment and desalination. It can best be utilized as an advanced pretreatment for desalination processes such as reverse osmosis (RO) and nanofiltration (NF) to protect the membranes from scaling and fouling. In the current study the rejection of trace organic compounds (TOrCs) such as pharmaceuticals, personal care products, plasticizers, and flame-retardants by FO and a hybrid FO-RO system was investigated at both the bench- and pilot-scales. More than 30 compounds were analyzed, of which 23 nonionic and ionic TOrCs were identified and quantified in the studied wastewater effluent. Results revealed that almost all TOrCs were highly rejected by the FO membrane at the pilot scale while rejection at the bench scale was generally lower. Membrane fouling, especially under field conditions when wastewater effluent is the FO feed solution, plays a substantial role in increasing the rejection of TOrCs in FO. The hybrid FO-RO process demonstrated that the dual barrier treatment of impaired water could lead to more than 99% rejection of almost all TOrCs that were identified in reclaimed water.     

Fate of endocrine-active compounds during municipal biosolids treatment: a review

For two decades, the fates of endocrine-disrupting compounds (EDCs) across various wastewater treatment processes have been studied using chemical and in vitro bioassay measurements. In comparison, little work has been conducted to track the fates of EDCs during municipal biosolids stabilization, particularly using bioassay approaches. This leads to knowledge gaps with respect to understanding which single or combined biosolid treatments facilitate EDC removal, and what the total endocrine-active potency of treated biosolids might be. These unknowns in turn heighten public opposition and distrust of biosolids reuse applications. This review aims to summarize what is currently known regarding EDC removal during commonly used full-scale biosolids treatment processes and highlights analytical challenges that are relevant when in vitro bioassays and chemical analyses are applied to biosolids samples.     

Kinetics of the oxidation of phenols and phenolic endocrine disruptors during water treatment with ferrate (Fe(VI))

The ability of ferrate (Fe(VI)) to oxidize phenolic endocrine-disrupting chemicals (EDCs) and phenols during water treatment was examined by determining the apparent second-order rate constants (k(app0) for the reaction of Fe(VI) with selected environmentally relevant phenolic EDCs (17alpha-ethinylestradiol, beta-estradiol, and bisphenol A) and 10 substituted phenols at pH values ranging from 6 to 11. The three selected groups of EDCs showed appreciable reactivity with Fe(VI) (kapp at pH 7 ranged from 6.4 x 102 to 7.7 x 10(2) M(-1) s(-1)). The k(app) for the substituted phenols studied at pH 7 ranged from 6.6 to 3.6 x 10(3) M(-1) s(-1), indicating that many other potential phenolic EDCs can be oxidized by Fe(VI) during water treatment. The Hammett-type correlations were determined for the reaction between HFeO4- and the undissociated (log(k) = 2.24-2.27sigma+) and dissociated phenol (log(k) = 4.33-3.60sigma+). A comparison of the Hammett correlation obtained for the reaction between HFeO4- and dissociated phenol with those obtained from other drinking water oxidants revealed that HFeO4- is a relatively mild oxidant of phenolic compounds. The effectiveness of Fe(VI) for the oxidative removal of phenolic EDCs was also confirmed in both natural water and wastewater.     

Determination of sex hormones and nonylphenol ethoxylates in the aqueous matrixes of two pilot-scale municipal wastewater treatment plants

Two analytical methods were developed and refined for the detection and quantitation of two groups of endocrine-disrupting chemicals (EDCs) in the liquid matrixes of two pilot-scale municipal wastewater treatment plants. The targeted compounds are seven sex hormones (estradiol, ethinylestradiol, estrone, estriol, testosterone, progesterone, and androstenedione), a group of nonionic surfactants (nonylphenol polyethoxylates), and their biodegradation byproducts nonylphenol and nonylphenol ethoxylates with one, two, and three ethoxylates. Solid phase extraction using C-18 for steroids and graphitized carbon black for the surfactants were used for extraction. HPLC-DAD and GC/MS were used for quantification. Each of the two 20 L/h pilot-scale plants consists of a primary settling tank followed by a three-stage aeration tank and final clarification. The primary and the waste-activated sludge are digested anaerobically in one plant and aerobically in the other. The pilot plants are fed with a complex synthetic wastewater spiked with the EDCs. Once steady state was reached, liquid samples were collected from four sampling points to obtain the profile for all EDCs along the treatment system. Complete removal from the aqueous phase was obtained for testosterone, androstenedione, and progesterone. Removals for nonylphenol polyethoxylates, estradiol, estrone, and ethinylestradiol from the aqueous phase exceeded 96%, 94%, 52%, and 50%, respectively. Levels of E3 in the liquid phase were low, and no clear conclusions could be drawn concerning its removal.     

Boric acid permeation in forward osmosis membrane processes: modeling, experiments, and implications

Forward osmosis (FO) is attracting increasing interest for its potential applications in desalination. In FO, permeation of contaminants from feed solution into draw solution through the semipermeable membrane can take place simultaneously with water diffusion. Understanding the contaminants transport through and rejection by FO membrane has significant technical implications in the way to separate clean water from the diluted draw solution. In this study, a model was developed to predict boron flux in FO operation. A strong agreement between modeling results and experimental data indicates that the model developed in this study can accurately predict the boron transport through FO membranes. Furthermore, the model can guide the fabrication of improved FO membranes with decreased boron permeability and structural parameter to minimize boron flux. Both theoretical model and experimental results demonstrated that when membrane active layer was facing draw solution, boron flux was substantially greater compared to the other membrane orientation due to more severe internal concentration polarization. In this investigation, for the first time, rejection of contaminants was defined in FO processes. This is critical to compare the membrane performance between different membranes and experimental conditions.     

Soluble, semivolatile phenol and nitrogen compounds in milk-processing wastewaters

Potable water is an essential and major input in processing our food supplies, and the continued growth in food manufacturing is placing increased pressure on this limited resource. Recycling and reuse of factory wastewater can lessen potable water use but requires a detailed understanding of wastewater properties. This study uses solid-phase extraction techniques with gas chromatography-mass spectrometry analysis to investigate trace-level semivolatile organic species in various waste and reference waters associated with the Burra Foods milk-processing plant located in Southeastern Australia. Our focus was on contaminants containing phenolic and heterocyclic nitrogen functional groups, which, because of their toxicity and persistence, may limit options for water recycling and reuse. Effluent from the wastewater treatment plant of the factory showed both the highest soluble carbon burden (47 mg/kg) and concentrations of target compounds. The target species found in these effluents included methyl phenol (13 mg/kg), hydroxy indole (9.8 mg/kg), synthetic tolyltriazoles (5.1 mg/kg) and alkyl phenol ethoxylates (0.2 mg/kg). Given the environmental stability of the tolyltriazoles, they may act as chemical markers where these effluents are used for purposes such as irrigation. Milk evaporator condensate waters, in contrast to the effluent, contained very few target species, with only low levels of pyrrolidine and piperidine derivatives such as ethylglutarimide (450 μg/L) detected. Although there were fewer target microcontaminants overall in the potable and creek reference waters, these samples had characteristic profiles. The potable water analysis revealed hydroxy cineole (2.1 μg/L) and the creek analysis revealed dichlorohydroxyacetophenone (0.3 μg/L), which were not detected in other waters. The compounds found in the wastewaters are likely to have been derived from milk or synthetic chemicals used in factory operations. The presence of nitrogen compounds in all the different milk-processing waters suggest their likely source was milk, probably milk phosphoproteins subjected to thermal, chemical, or microbial degradation. Our benign results for the condensates suggest it may be possible to substitute condensate for potable water with minimal pretreatment, both within the plant and in other applications, such as irrigation of recreation turf.     

Integrating forward osmosis into microbial fuel cells for wastewater treatment, water extraction and bioelectricity generation

A novel osmotic microbial fuel cell (OsMFC) was developed by using a forward osmosis (FO) membrane as a separator. The performance of the OsMFC was examined with either NaCl solution or artificial seawater as a catholyte (draw solution). A conventional MFC with a cation exchange membrane was also operated in parallel for comparison. It was found that the OsMFC produced more electricity than the MFC in both batch operation (NaCl solution) and continuous operation (seawater), likely due to better proton transport with water flux through the FO membrane. Water flux from the anode into the cathode was clearly observed with the OsMFC but not in the MFC. The solute concentration of the catholyte affected both electricity generation and water flux. These results provide a proof of concept that an OsMFC can simultaneously accomplish wastewater treatment, water extraction (from the wastewater), and electricity generation. The potential applications of the OsMFC are proposed for either water reuse (linking to reverse osmosis for reconcentration of draw solution) or seawater desalination (connecting with microbial desalination cells for further wastewater treatment and desalination).     

Partition of endocrine-disrupting chemicals between colloids and dissolved phase as determined by cross-flow ultrafiltration

Cross-flow ultrafiltration (CFUF) was developed first for the isolation of natural colloids and subsequently for determining the partition of selected endocrine-disrupting chemicals (EDCs) between river colloids and dissolved phase. In this study, a 1-kDa Millipore Pellicon 2 cartridge type CFUF system was validated using a range of molecular probes spiked in natural waters. Results show that good retention (>80%) of high molecular weight (HMW, >1 kDa) molecules and low retention of low molecular weight (LMW, <1 kDa) molecules can be achieved at high concentration factor (cf) values in sampling mode or over long time scales in recirculation mode. The interactions between aquatic colloids and EDCs were studied by mixing EDCs, water, and colloids previously isolated by CFUF for a certain duration, followed by the separation of the target compounds between the truly dissolved and colloid-bound phases by CFUF and analysis by gas chromatography-mass spectrometry (GC-MS). The kinetics of EDCs binding to colloids were relatively rapid, reaching equilibrium within 5 min. The mass balance of chosen EDCs through CFUF system was fully investigated, with good recovery for the relatively polar EDCs such as estrone and 17beta-estradiol. On the basis of EDC sorption by colloids, the partition coefficient normalized to colloidal organic carbon content (Kcoc) was 8.85 x 10(3), 1.50 x 10(4), 8.85 x 10(3), 4.87 x 10(4), and 1.59 x 10(4) mL/g for bisphenol A, estrone, 17beta-estradiol, 17alpha-ethynylestradiol, and 16alpha-hydroxyestrone, respectively, which are comparable with the values reported in the literature. In addition, it has been shown that the Kcoc values of EDCs were relatively independent of their octanol-water partition coefficient (Kow) values, suggesting the important role of different binding mechanisms other than nonspecific hydrophobic interaction between EDCs and natural colloids. As the CFUF-GC-MS method can be used to quantify very low concentration of pollutants and is not limited to fluorescent compounds, it has the potential to be a widely applicable separation/analytical tool for determining the partition of organic pollutants between colloidal materials and dissolved phase.     

Destruction of estrogens using Fe-TAML/peroxide catalysis

Endocrine disrupting chemicals (EDCs) impair living organisms by interfering with hormonal processes controlling cellular development Reduction of EDCs in water by an environmentally benign method is an important green chemistry goal. One EDC, 17alpha-ethinylestradiol (EE2), the active ingredient in the birth control pill, is excreted by humans to produce a major source of artificial environmental estrogenicity, which is incompletely removed by currenttechnologies used by municipal wastewater treatment plants (MWTPs). Natural estrogens found in animal waste from concentrated animal feeding operations (CAFOs) can also increase estrogenic activity of surface waters. An iron-tetraamidomacrocyclic ligand (Fe-TAML) activator in trace concentrations activates hydrogen peroxide and was shown to rapidly degrade these natural and synthetic reproductive hormones found in agricultural and municipal effluent streams. On the basis of liquid chromatography tandem mass spectrometry, apparent half-lives for 17 alpha- and 17 beta-estradiol, estriol, estrone, and EE2 in the presence of Fe-TAML and hydrogen peroxide were approximately 5 min and included a concomitant loss of estrogenic activity as established by E-Screen assay.     

Performance of forward (direct) osmosis process: membrane structure and transport phenomenon

The performance of a forward (direct) osmosis (FO) process was investigated using a laboratory-scale unit to elucidate the effect of membrane structure and orientation on waterflux. Two types of RO membrane and a FO membrane were tested using ammonium bicarbonate, glucose, and fructose as the draw solution to extract water from a saline feed solution. The FO membrane was able to achieve higher water flux than the RO membranes under the same experimental conditions while maintaining high salt rejection of greater than 97%. Increasing operating temperature increased the water flux in FO process. To investigate the effect of membrane orientation on water flux, the FO membrane was tested normally (dense selective layer facing draw solution) and reversely (dense selective layer facing feed solution). Explanations on transport phenomenon in FO process were proposed which explain the observation that the FO membrane, when used in the normal orientation, performed better due to lesser internal concentration polarization. This study suggests that an ideal FO membrane should consist of a thin dense selective layer without any loose fabric support layer.     

Degradation and behavior of natural steroid hormones in cow manure waste during biological treatments and ozone oxidation

An efficient treatment process for screened cow manure waste, particularly for the degradation of natural steroid hormones, was developed. The first step in this process was a draw-and-fill process for thermophilic anaerobic digestion. After fourfold dilution with tap water, continuous feeding was performed for the aerobic treatment of the effluent from the anaerobic treatment. Batchwise ozone oxidation was then carried out for the degradation of the natural steroid hormones that remained in the effluent from the aerobic treatment. A yeast two-hybrid assay was performed to evaluate hormonal degradation. Significant reductions in the concentrations of total VFA, BOD(5), COD(Cr), TOC, TS, VSS, and natural steroid hormones were demonstrated in the effluent from the biological treatments. The removal ratios of such concentrations were 99.7%, 90%, 79%, 84%, 51%, 58%, and 99%, respectively. Although the concentrations of the remaining TOC and COD(Cr) remained constant, natural steroid hormones were completely removed by ozone oxidation.     

Polyelectrolyte-promoted forward osmosis-membrane distillation (FO-MD) hybrid process for dye wastewater treatment

Polyelectrolytes have proven their advantages as draw solutes in forward osmosis process in terms of high water flux, minimum reverse flux, and ease of recovery. In this work, the concept of a polyelectrolyte-promoted forward osmosis-membrane distillation (FO-MD) hybrid system was demonstrated and applied to recycle the wastewater containing an acid dye. A poly(acrylic acid) sodium (PAA-Na) salt was used as the draw solute of the FO to dehydrate the wastewater, while the MD was employed to reconcentrate the PAA-Na draw solution. With the integration of these two processes, a continuous wastewater treatment process was established. To optimize the FO-MD hybrid process, the effects of PAA-Na concentration, experimental duration, and temperature were investigated. Almost a complete rejection of PAA-Na solute was observed by both FO and MD membranes. Under the conditions of 0.48 g mL(-1) PAA-Na and 66 °C, the wastewater was most efficiently dehydrated yet with a stabilized PAA-Na concentration around 0.48 g mL(-1). The practicality of PAA-Na-promoted FO-MD hybrid technology demonstrates not only its suitability in wastewater reclamation, but also its potential in other membrane-based separations, such as protein or pharmaceutical product enrichment. This study may provide the insights of exploring novel draw solutes and their applications in FO related processes.     

Treatment of model soils contaminated with phenolic endocrine-disrupting chemicals with laccase from Trametes sp. in a rotating reactor

An enzymatic treatment system for the remediation of sand contaminated with endocrine-disrupting chemicals (EDCs) was studied. Laccase from Trametes sp. (Laccase Daiwa) decreased the amounts of nonylphenol, octylphenol, bisphenol A and ethynylestradiol (synthetic estrogen) adsorbed on sea sand (2 micromol g(-1)) in a test tube with shaking. The phenolic endocrine-disrupting chemicals might have polymerized via enzymatic conversion to their phenoxy radicals. The optimum pH for the enzymatic treatment was approximately 5. A rotating reactor was used for scaling up the enzymatic treatment. The reaction rate increased by rotating the reactor. The optimum speed of revolution was 10-15 rpm for the treatment of nonylphenol. The amounts of octylphenol, bisphenol A, and ethynylestradiol also decreased enzymatically in the reactor. Our enzymatic treatment system with a rotating reactor will be useful for the treatment of soil highly polluted with phenolic EDCs.     

Endocrine-disrupting chemicals in ovarian function: effects on steroidogenesis, metabolism and nuclear receptor signaling

Endocrine-disrupting chemicals (EDCs) are exogenous agents with the ability to interfere with processes regulated by endogenous hormones. One such process is female reproductive function. The major reproductive organ in the female is the ovary. Disruptions in ovarian processes by EDCs can lead to adverse outcomes such as anovulation, infertility, estrogen deficiency, and premature ovarian failure among others. This review summarizes the effects of EDCs on ovarian function by describing how they interfere with hormone signaling via two mechanisms: altering the availability of ovarian hormones, and altering binding and activity of the hormone at the receptor level. Among the chemicals covered are pesticides (e.g. dichlorodiphenyltrichloroethane and methoxychlor), plasticizers (e.g. bisphenol A and phthalates), dioxins, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons (e.g. benzo[a]pyrene).     

Combined sewer overflows: an environmental source of hormones and wastewater micropollutants

Data were collected at a wastewater treatment plant (WWTP) in Burlington, Vermont, USA, (serving 30,000 people) to assess the relative contribution of CSO (combined sewer overflow) bypass flows and treated wastewater effluent to the load of steroid hormones and other wastewater micropollutants (WMPs) from a WWTP to a lake. Flow-weighted composite samples were collected over a 13 month period at this WWTP from CSO bypass flows or plant influent flows (n = 28) and treated effluent discharges (n = 22). Although CSO discharges represent 10% of the total annual water discharge (CSO plus treated plant effluent discharges) from the WWTP, CSO discharges contribute 40-90% of the annual load for hormones and WMPs with high (>90%) wastewater treatment removal efficiency. By contrast, compounds with low removal efficiencies (<90%) have less than 10% of annual load contributed by CSO discharges. Concentrations of estrogens, androgens, and WMPs generally are 10 times higher in CSO discharges compared to treated wastewater discharges. Compound concentrations in samples of CSO discharges generally decrease with increasing flow because of wastewater dilution by rainfall runoff. By contrast, concentrations of hormones and many WMPs in samples from treated discharges can increase with increasing flow due to decreasing removal efficiency.     

Natural occurrence of steroid hormones in food

The natural occurrence of the sex steroid hormones progesterone, testosterone, 17β-estradiol and estrone in food was investigated in a survey of the German market basket. The main metabolic precursors, intermediates and metabolites (pregnenolone, androstenedione, hydroxyprogesterone, dehydroepiandrosterone (DHEA), dihydrotestosterone, androsterone, 17α-estradiol and estriol) were also included in the investigation. Particular attention was paid to DHEA, which is said to have anti-aging properties. Analysis was carried out by gas chromato-graphy-mass spectrometry (GC-MS). The steroid patterns of pork, meat products, fish and poultry resemble those known for beef. Milk and milk products reflect the hormone profile of female cattle with high amounts of progesterone, which accumulates with increasing milk fat content. Milk products supply about 60–80% of ingested female sex steroids. Eggs are a considerable source of any of the investigated steroids and contribute to the nutritional hormone intake in the same order as meat and fish (10–20%). In vegetable food no estrogens could be detected. Plants supply testosterone in the same order as meat and milk products (20–40%) though. They contain considerable amounts of hormone precursors as well (contribution to DHEA supply: about 80%). In comparison to the human daily production of steroid hormones the nutritional supply (about 10 μgd⁻¹ progesterone, 0.05 μg d⁻¹ testosterone, 0.1 μg d⁻¹ estrogens, 0.5 μg d⁻¹ DHEA) is insignificant.     

Cloning and in vitro expression and characterization of the androgen receptor and isolation of estrogen receptor alpha from the fathead Minnow (Pimephales promelas)

In vitro screening assays designed to identify hormone mimics or antagonists typically use mammalian (rat, human) estrogen (ER) and androgen receptors (AR). Although we know that the amino acid sequences of steroid receptors in nonmammalian vertebrates are not identical to the mammalian receptors, a great deal of uncertainty exists as to whether these differences affect interactions of potential endocrine-disrupting chemicals (EDC) with the receptors. This leads to substantial uncertainty with respect to the utility of mammalian-based screening assays to predict possible effects of EDCs in nonmammalian wildlife. This paper describes preparation of a cDNA library from a small fish model commonly used in ecological risk assessments, the fathead minnow (Pimphales promelas). The cDNA library was subsequently used to isolate and sequence both AR and ERalpha. In addition, the fathead minnow (fh)AR was expressed and characterized with respect to function using saturation and competitive binding assays in COS monkey kidney cells. Saturation experiments along with subsequent Scatchard analysis determined that the Kd of the fhAR for the potent synthetic androgen R1881 was 1.8 nM, which is comparable to that for the human AR in the same assay system. In COS whole cell competitive binding assays, potent androgens such as dihydrotestosterone and 11-ketotestosterone were also shown to be high affinity ligands for the fhAR. We also report affinity of the receptor for a number of environmental contaminants including the AR agonists androstenedione and 17a- and 17beta-trenbolone;AR antagonists such as p,p'-DDE, linuron, and vinclozolin; and the ER agonist 17beta-estradiol. Future plans include comparison of binding affinities of the fhAR to those of the human AR, also expressed in COS cells, using a range of EDCs.