Quantification of selected steroid hormones (17β-Estradiol and 17α-Ethynylestradiol) in wastewater treatment plants in Klang Valley (Malaysia)

Global insight into the occurrence, treatment technologies and ecological risk of emerging contaminants in sanitary sewers: Effects of the SARS-CoV-2 coronavirus pandemic

The SARS-CoV-2 pandemic caused changes in the consumption of prescribed/non-prescribed drugs and the population's habits, influencing the detection and concentration of emerging contaminants (ECs) in sanitary sewage and harming environmental and health risks. Therefore, the present work sought to discuss current literature data on the effects of the "COVID-19 pandemic factor" on the quality of raw sewage produced over a five-year period (2018-2019: pre-pandemic; 2020-2022: during the pandemic) and biological, physical, chemical and hybrid treatment technologies, influencing factors in the removal of ECs and potential ecological risks (RQs). Seven hundred thirty-one publications correlating sewage and COVID-19 were identified: 184 pre-pandemic and 547 during the pandemic. Eight classes and 37 ECs were detected in sewage between 2018 and 2022, with the "COVID-19 pandemic factor" promoting an increase in estrogens (+31,775 %), antibiotics (+19,544 %), antiepileptics and antipsychotics (+722 %), pesticides (+200 %), analgesics, anti-inflammatories and anticoagulants (+173 %), and stimulant medications (+157 %) in sanitary sewage. Among the treatment systems, aerated reactors integrated into biomembranes removed >90 % of cephalexin, clarithromycin, ibuprofen, estrone, and 17β-estradiol. The absorption, adsorption, and biodegradation mechanisms of planted wetland systems contributed to better cost-benefit in reducing the polluting load of sewage ECs in the COVID-19 pandemic, individually or integrated into the WWTP. The COVID-19 pandemic factor increased the potential ecological risks (RQs) for aquatic organisms by 40 %, with emphasis on clarithromycin and sulfamethoxazole, which changed from negligible risk and low risk to (very) high risk and caffeine with RQ > 2500. Therefore, it is possible to suggest that the COVID-19 pandemic intensified physiological, metabolic, and physical changes to different organisms in aquatic biota by ECs during 2020 and 2022.

Coastal wastewater treatment plants as a source of endocrine disrupting micropollutants: a case study of Lithuania in the Baltic Sea

In temperate coastal areas, the resident population often increases during holidays. As a result, this can lead to higher wastewater production and release of pollutants. The connection between micropollutants such as plasticizers and hormones with the changing resident population along the Baltic Sea coast has yet to be thoroughly studied. Therefore, we have monitored the wastewater quality and specific micropollutants before and after treatment at wastewater treatment plants (WWTPs) at small and large seaside resorts. The findings indicate a strong link between tourism indicators and wastewater production during the summer months. The rise in different micropollutants, specifically plasticizers, during the summer demonstrates a link with tourism activity. Furthermore, we have identified a non-linear association between the tourism indicators and the total estrogenic equivalent (EEQ). Overall, this research particularly emphasizes the growing importance of wastewater quality in terms of conventional nutrient pollution and various micropollutants.

Removal of estrogens from primary settled sewage by repeated culture of Selenastrum capricornutum

Biotransformation and biodegradation of estrogenic compounds by bacteria and even fungi have been reported widely, but the role of microalgae in the elimination of estrogens from municipal wastewater treatment plants and their interaction with other microorganisms in wastewater are not clear. This study reported the feasibility of repeatedly removing a mixture of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), each was 100 μg L-1, from primary settled municipal sewage by Selenastrum capricornutum (SC), a ubiquitous microalga, in four exposure cycles, each lasted 7 days, and how they interacted with the microbial consortium in sewage. Mixed estrogen in sewage stimulated the growth of SC, and the indigenous microorganisms in sewage also affected the microalgal growth. The indigenous microorganisms, particularly bacteria, could easily remove E2 (with 99.5% removal), so the role of SC was insignificant. On the contrary, EE2 was difficult to remove by indigenous microorganisms but the removal was significantly enhanced by SC, with almost all spiked EE2 being removed, even at the end of the fourth cycle (with 99.0% removal). These results indicated that SC, together with the indigenous microorganisms in wastewater, could be repeatedly used for simultaneous removal of E2 and EE2 from municipal sewage.

Steroid hormone-inducible biosensor based on EGFP-tagged and environmental application

Steroid hormones as a class of emerging organic pollutant and high concern, due to their potential risks for human and environmental. Accurate analytical methods of steroid hormones are necessary in quantifying and monitoring. Biosensor is a promising technique. In this study, though part of 3α-HSD DNA to construct a regulatory plasmid and with the EGFP reporter gene to generate a reporter plasmid. Separately transformed into Escherichia coli strain BL21 and extracted the cell lysates as novel biosensor reagents. Analyzed the total amounts of steroid hormones in water, sediment, and soil samples using biosensor reagents, and compared these results with those obtained by HPLC. In summary, detection method using an EGFP reporter that can detect trace amounts of steroid hormones to reached fg/L. The optimal reaction time range and temperature were 30 min and 30 °C, respectively, while the most suitable organic solvent for the steroid hormone was 100% ethanol, up to 96-well plate format. This method is very suitable for high-throughput detection of environmental steroid hormone pollutants.

Mechanism of 17β-estradiol degradation by Rhodococcus equi via the 4,5-seco pathway and its key genes

Steroid estrogens have been detected in oceans, rivers, lakes, groundwaters, soils, and even urban water supply systems, thereby inevitably imposing serious impacts on human health and ecological safety. Indeed, many estrogen-degrading bacterial strains and degradation pathways have been reported, with the 4,5-seco pathway being particularly important. However, few studies have evaluated the use of the 4,5-seco pathway by actinomycetes to degrade 17β-estradiol (E2). In this study, 5 genes involved in E2 degradation were identified in the Rhodococcus equi DSSKP-R-001 (R-001) genome and then heterologously expressed to confirm their functions. The transformation of E2 with hsd17b14 reached 63.7% within 30 h, resulting in transformation into estrone (E1). Furthermore, we found that At1g12200-encoded flavin-binding monooxygenase (FMO_At1g12200) can transform E1 at a rate of 51.6% within 30 h and can transform E1 into 4-hydroxyestrone (4-OH E1). In addition, catA and hsaC genes were identified to further transform 4-OH E1 at a rate of 97-99%, and this reaction was accomplished by C-C cleavage at the C4 position of the A ring of 4-OH E1. This study represents the first report on the roles of these genes in estrogen degradation and provides new insights into the mechanisms of microbial estrogen metabolism and a better understanding of E2 degradation via the 4,5-seco pathway by actinomycetes.

Hormetic effect of 17α-ethynylestradiol on activated sludge microbial community response

Synthetic estrogen analogues are among the most potent estrogenic contaminants in effluents from wastewater treatment plants. Although its effects have been well elucidated in the feminization of male fish and interference with the endocrine systems in humans, it has not been fully explored in the activated sludge (AS) microbiome, particularly EE2 (17α-ethynylestradiol). Therefore, in this study, the bacterial community shift in a 6-day laboratory-scale reactor in environmental (0, 5, 10, and 100 ng/L) and predictive elevated concentrations (5, 10, and 100 mg/L) of EE2 was investigated using culture-based and metagenomics approaches. Results showed significant changes (t-test, all p < 0.05) between initial and final physicochemical parameters (pH, DO, and EC). Although environmental concentrations showed a slight decrease in microbial counts (5.6 × 10⁶ to 4.6 × 10⁶ CFU/ml) after a 24-h incubation for the culturable approach, the predictive elevated concentrations (5 to 100 mg/L) revealed a drastic microbial counts reduction (5.6 × 10⁶ to 8 × 10² CFU/ml). The metagenomic data analysis uncovered that bacterial communities in the control sample were dominated by Proteobacteria, followed by Bacteroidetes and Firmicutes. The taxonomic classification after exposure of microbial communities in various concentrations revealed significant differences in community composition between environmental concentration (Shannon indices between 2.58 to 3.68) and predictive elevated concentrations (Shannon indices between 2.24 and 2.84; t-test, all p < 0.05). The EE2 enriched seven OTUs were Novosphingobium, Cloacibacterium, Stenotrophomonas, Enterobacteriaceae_unclassified, Stenotrophomonas, Enterobacteriaceae_unclassified and Rhodobacteraceae_unclassified. These results were supported by a dehydrogenase activity (DHA) test, which demonstrated less (about 40%) DHA in predictive elevated concentrations than in environmental concentrations. Notwithstanding, these findings suggest that EE2 may possess potent hormetic effect as evidenced by promotion of microbiome richness and dehydrogenase activity of AS in lower EE2 doses.

Membrane biorreactor, reverse osmosis and UV/H2O2 process integration for ethinylestradiol removal: A cost-benefit analysis

The presence of 17α-ethinylestradiol (EE2) in water bodies and its potential risks to human health and the environment have been frequently described in the literature, in addition to its limited removal in conventional wastewater treatment plants. Many studies have evaluated this removal by advanced processes, including photodegradation and membrane separation. A significant number of studies also assess the economic analysis of these technologies. However, few works articulate both perspectives: the specificity involved in estrogen removal and economic analysis. Given this gap, this work evaluates the synergies involved in the integration of reverse osmosis (RO) and advanced oxidative processes by UV/H₂O₂ (AOP) in the post-treatment of membrane bioreactor (MBR) effluents. To this end, the integrated plant possibilities were represented through a superstructure that integrated EE2 removal and cost models of each process. The use of a Hook and Jeeves optimizer considering these processes standard operating conditions made it possible to determine the percentage of stream division for each equipment and even the absence of any of these in an integrated plant with lower cost and EE2 concentration output below the recommended limit by the European Union (0.035 ng.L^-1). For EE2 feed content up to 3 ng.L^-1, the lowest cost configuration is to route 20% of the MBR effluent to the AOP, 30% to the RO, and the remainder to a final mixer. For concentrations above 15 ng.L^-1, the sufficient and lowest cost configuration is the MBR-RO-AOP series. Intermediate values have a more advantageous integrated process configuration with the parallel and series configurations combined, with a stream distribution dependent on the feed concentration. Moreover, a parameter sensitivity analysis was performed, clarifying paths for design improvements and acting as a systematic guide for future work in this area. This analysis highlights that EE2 removal is more sensitive to temperature (1.04%), feed substrate concentration (-1.18%), solid retention time in the MBR (0.32%), and irradiance in AOP (-0.46%). Investment costs also proved to be decisive in the composition of the total cost, enhancing the relevance of the maturation process of these technologies in light of simple changes in operating parameters.

Estrogenic activity and ecological risk of steroids, bisphenol A and phthalates after secondary and tertiary sewage treatment processes

Effluents of sewage treatment plants (STPs) are an important source of estrogenic substances to the receiving water bodies affecting their ecological safety. In this study, steroids, bisphenol A (BPA) and phthalates were assessed in the secondary (SE) and tertiary effluent (TE) of three typical urban STPs in Beijing (China). In addition, the overall estrogenic activity in these effluents was assessed by an in-vitro bioassay (ERE-CALUX). Results showed that the concentrations and activities of estrogenic compounds in TE were lower than those in SE. The residual concentration of 17β-estradiol (E2) was the highest among the detected steroids, accounting for 51.6 ± 5.1% in SE and 57.5 ± 24.8% in TE. The residual level (25.2-41.6 ng/L) of BPA in effluents was significantly higher than that of steroids (0.2-28.8 ng/L). The residual concentration of diethyl phthalate was the highest among the detected phthalates accounting for 47.1 ± 5.1% in SE and 37.6 ± 11.5% in TE. Steroids and BPA had a higher removal rate (83.5% and 96.7%) in secondary and tertiary treatment than phthalates (68.8% and 83.1%). The hydrophobic characteristics of these estrogenic compounds determined the removal mechanism. The removal of steroids, BPA, dimethyl phthalate and diethyl phthalate (LogKow= 1.61-4.15) mainly occurred through biodegradation in the water phase, while the removal of dibutyl phthalate, butylbenzyl phthalate and di(2-ethylhexyl) phthalate (LogKow= 4.27-7.50) mainly occurred in the solid phase after adsorption on and sedimentation of the suspended particulate matter. According to ERE-CALUX, the estrogenic activity in the final STP effluents was 3.2-45.6 ng E2-equivalents/L, which is higher than reported levels in the effluents of European STPs. Calculation of estrogenic equivalents by using substance specific chemical analysis indicated that the dominant contributor was E2 (56.4-88.4%), followed by 17α-ethinylestradiol (EE2) (4.1-34.8%), both also exerting a moderate risk to the aquatic ecosystem. While the upgrade of treatment processes in STPs has efficiently reduced the emission of estrogenic substances, their ecological risk was not yet phased out.

Occurrence, abundance, and distribution of microplastics pollution: an evidence in surface tropical water of Klang River estuary, Malaysia

Microplastics have been considered as contaminants of emerging concern due to ubiquity in the environment; however, the occurrence of microplastics in river estuaries is scarcely investigated. The Klang River estuary is an important ecosystem that receives various contaminants from urbanised, highly populated areas and the busiest maritime centre in Selangor, Malaysia. This study investigates the abundance and characteristics of microplastics in surface water of the Klang River estuary. The abundance of microplastics ranged from 0.5 to 4.5 particles L^-1 with a mean abundance of 2.47 particles L^-1. There is no correlation between the abundance of microplastics and physicochemical properties, while there is a strong correlation between salinity and conductivity. The microplastics were characterised with a stereomicroscope and attenuated total reflection-Fourier transform infrared spectroscopy to analyse size, shape, colour, and polymer composition. The microplastics in the surface water were predominantly in the 300-1000 μm size class, followed by > 1000 μm and < 300 μm, and were mostly transparent fibres, fragments, and pellets. Polyamide and polyethylene were the main polymer types in the composition of the microplastics, suggesting that the microplastics originated from heavily urbanised and industrial locations such as the port, jetty, and residential areas. The widespread occurrence of microplastics in the environment and subsequent penetration of aquatic food webs may pose a serious threat to organisms. This study provides baseline data and a framework for further investigation of microplastic contamination in estuaries.

A review of 17α-ethynylestradiol (EE2) in surface water across 32 countries: Sources, concentrations, and potential estrogenic effects

17α-ethynylestradiol (EE2) is a synthetic estrogen with very strong estrogenic potency. Due to its wide usage in human and livestock as well as its high recalcitration to biodegradation, it was ubiquitous in different environment. This review summarized EE2 concentration levels in surface waters among 32 countries across seven continents. EE2 concentrations varied greatly in different surface waters, which ranged from not detected to 17,112 ng/L. The top 10 countries ranked in the order of high to low average EE2 concentration in surface water, were Vietnam, Cambodia, China, Laos, Brazil, Argentina, Kuwait, Thailand, Indonesia and Portugal, with the respective mean concentrations of 27.7, 22.1, 21.5, 21.1, 13.6, 9.6, 9.5, 8.8, 7.6 and 6.6 ng/L. Generally speaking, the EE2 concentration levels in surface waters in developing countries were much higher than those in developed countries. EE2 in effluent of municipal wastewater treatment plant (WWTP) was the dominant source to most countries, which suggested that improving the EE2 removal performance of municipal WWTP is the key to mitigate EE2 contamination to surface water body. Livestock, hospital, pharmacy factory and aquaculture wastewaters were also the important sources, but further work should be performed to elucidate their contribution. Evaluation based on estrogenic effects, the EE2-derived estrogen equivalence in surface waters ranged from 0 to 33 ng E2/L, among which about 65% of surface waters among 32 countries were at risk or high risk, indicating global serious EE2 contamination. MAIN FINDING: EE2 concentration in surface waters across 32 countries were summarized, along which its potential estrogenic effects were evaluated.

Recent Advances in Solid-Phase Extraction (SPE) Based on Molecularly Imprinted Polymers (MIPs) for Analysis of Hormones

Steroid hormones are active substances that are necessary in the normal functioning of all physiological activities in the body, such as sexual characteristics, metabolism, and mood control. They are also widely used as exogenous chemicals in medical and pharmaceutical applications as treatments and at times growth promoters in animal farming. The vast application of steroid hormones has resulted in them being found in different matrices, such as food, environmental, and biological samples. The presence of hormones in such matrices means that they can easily come into contact with humans and animals as exogenous compounds, resulting in abnormal concentrations that can lead to endocrine disruption. This makes their determination in different matrices a vital part of pollutant management and control. Although advances in analytical instruments are constant, it has been determined that these instruments still require some sample preparation steps to be able to determine the occurrence of pollutants in the complex matrices in which they occur. Advances are still being made in sample preparation to ensure easier, selective, and sensitive analysis of complex matrices. Molecularly imprinted polymers (MIPs) have been termed as advanced solid-phase (SPE) materials for the selective extraction and preconcentration of hormones in complex matrices. This review explores the preparation and application of MIPs for the determination of steroid hormones in different sample types.

Fungal laccase-triggered 17β-estradiol humification kinetics and mechanisms in the presence of humic precursors

Naturally-occurring phenolic acids (PAs) act as humic precursors that participate in the conversion behaviors and coupling pathways of steroidal estrogens (SEs) during laccase-triggered humification processes (L-THPs). Herein, the influences and mechanisms of PAs on Trametes versicolor laccase-evoked 17β-estradiol (E2) conversion kinetics and humification routes were explored. Fungal laccase was fleet in converting > 99% of E2, and the calculated pseudo-first-order velocity constant and half-time values were respectively 0.039 min^-1 and 17.906 min. PAs containing an O-dihydroxy moiety such as gallic acid and caffeic acid evidently hampered E2 humification owning to the yielded highly reactive O-quinones reversed E2 radicals by hydrogen transfer mechanism, implying that the inhibition effect was enormously dependent upon the number and position of the phenolic -OH present in humic precursors. Oligomers and polymers with carbon-carbon/oxygen links were tentatively found as E2 main humified species resulting from laccase-evoked successive oxidative-coupling. Note that PAs participating in the humification also encountered oxydehydrogenation, self-polymerization, and cross-binding to E2. Interestingly, the -COOH and -OCH₃ groups of PAs could be deprived in radical-caused self/co-polymerization. The generation of humified products not only circumvented the environmental risks of parent compounds but accelerated global carbon sequestration. To our knowledge, this is the first in-depth revelation of the humification pathways and related mechanisms of SEs with humic precursors in aquatic ecosystems by L-THPs.

Occurrence and removal of 17α-ethynylestradiol (EE2) in municipal wastewater treatment plants: Current status and challenges

As a synthetic estrogen, 17α-ethynylestradiol (EE2) has been known to show the strong estrogenic potency. This work critically reviewed the occurrence and removal of EE2 in municipal wastewater treatment plants (WWTPs). Based on the on-site investigations from 282 municipal WWTPs across 29 countries, the concentrations of EE2 in influent and effluent ranged from n.d-7890 and n.d-549 ng/L, with respective average concentrations of 78.4 and 12.3 ng/L. The average effluent concentration of EE2 was more than 61 times higher than the reported lowest-observed-effect concentration, indicating an urgent need for removing EE2 in WWTPs. The calculated removal efficiencies of EE2 in different wastewater treatment processes varied from -100%-100%. Averagely, 47.5% of EE2 was removed in the primary treatment process, 55.3% by biological filter treatment, 59.4% by lagoon and 71.5% by activated sludge process. The observed removal of EE2 in municipal WWTP could be mainly attributed to adsorption and biodegradation, which could be predicted according to its solid-water distribution coefficients and biodegradation rate constants. However, it should be noted that the predicted removal of EE2 was found to deviate from the in-plant observation, likely attributing to the existence of EE2 conjugates in raw municipal wastewater. Therefore, the effect of EE2 conjugates on the EE2 removal in WWTPs should be taken into account in future.

Ethinylestradiol removal of membrane bioreactor effluent by reverse osmosis and UV/H2O2: A technical and economic assessment

Synthetic hormone 17α-ethinylestradiol (EE2) is not completely removed by conventional wastewater treatment plants and therefore is often detected in surface and groundwater, sludge and sediments. Due to its persistence in the environment and its estrogenic potential, a high removal of EE2 from wastewaters before its disposal has become a concern from an environmental point of view, particularly when considering urban reuse applications. This work investigated the application of advanced processes to treat synthetic municipal wastewater containing EE2 after treatment in a membrane bioreactor (MBR). Two advanced processes were assessed: the first is advanced oxidation process (AOP), using hydrogen peroxide (H₂O₂) and ultraviolet (UV) light (route MBR-AOP) and the second, reverse osmosis (RO), in this case using UV/H₂O₂ to treat the retentate from RO (route MBR-RO). EE2 concentration in final effluent was one order of magnitude lower in route MBR-AOP than in route MBR-RO. Implications for disposal or water reuse were discussed considering the importance of other water quality parameters as well. Economic estimates for CAPEX, OPEX and total cost were made. The introduction of the oxidative step (UV/H₂O₂) after MBR caused an increase in the total cost of US$ 0.39/m³. In turn, route MBR-RO increased the total process cost by US$ 0.86/m³, showing that reduction of volume to be treated by UV/H₂O₂ in this route did not offset the cost associated with the acquisition and operation of RO. The total cost was estimated at US$ 2.47/m³ for MBR-AOP and US$ 2.94/m³ for MBR-RO for a design flow of 10 m³/h.

Optimized constructed wetlands enhance the removal and reduce the risks of steroid hormones in domestic wastewater

Constructed wetland (CW) has been proved to be a reliable wastewater treatment technology for removal of various contaminants. However, the removal of specific contaminants such as steroid hormones by wetlands without optimized design parameters would be unstable. Here we investigated the removal mechanism of steroid hormones by constructed wetlands, and optimized various design parameters for the removal of these contaminants in wastewater. Four CW systems with different designs (artificial aeration or series wetland unit) were constructed outdoors to treat raw domestic sewage. The results showed that 9 steroid hormones were detected at concentrations from 7.13 ± 0.28 ng/L to 3040 ± 199 ng/L, with their removal rates ranged from 14.7 ± 3.04% to 100% by these CWs. It was also found that enhanced designs including aeration and series wetland unit can effectively improve the removal of steroid hormones. Combined with ecological risk assessment, CW4 (aerated VSSF CW and aerated HSSF CW combination) was the best design for removal of steroid hormones, but CW2 (VSSF CW with artificial aeration) may be better for urban areas with limited space. Based on mass balance calculation, biodegradation played a dominant role in removing steroid hormones by CWs, while substrate adsorption and plant uptake also played a limited role. The findings from this study suggest that CWs can be optimized to better remove steroid hormones in sewage before discharge into receiving environments.

Extended suspect screening to identify contaminants of emerging concern in riverine and coastal ecosystems and assessment of environmental risks

A suspect screening methodology was developed for the fast and reliable identification of 360 contaminants of emerging concern (CECs) of anthropogenic origin in the vulnerable area of the Ebro Delta (Catalonia, Spain) and to track for potential contamination sources. The suspect screening methodology was combined with a risk assessment approach to prioritize the most ecologically relevant CECs. Out of the 360 suspects, 37 compounds were tentatively identified, 22 of which were fully confirmed using isotopically labelled standards. The detected suspect compounds included pesticides, pharmaceuticals, personal care products, stimulants and their metabolites. Pesticides were more ubiquitous in irrigation and drainage channels, while pharmaceuticals, stimulants, and personal care products were the most common in effluent wastewaters, in the receiving freshwater systems as well as in the marine environment. Ten compounds were found to be of high ecological concern, including the pharmaceuticals telmisartan, venlafaxine, and carbamazepine, the herbicides terbuthylazine, desethylterbuthylazine, and terbutryn, the fungicides azoxystrobin, tebuconazole and prochloraz and the insecticide tebufenozide. These compounds could be used as markers of anthropogenic contamination in riverine and coastal ecosystems.

Quantification, removal and potential ecological risk of emerging contaminants in different organic loads of swine wastewater treated by integrated biological reactors

This study aims to evaluate the dynamics and their ecological risks for aquatic species of lipid regulator, nervous stimulant, anti-inflammatory and endocrine disrupters in an upflow anaerobic sludge blanket (UASB), submerged aerated biological filters (SABF) and horizontal subsurface flow constructed wetland (HSSF-CW) reactors that treat swine wastewater. Four organic loads of swine wastewater (SW) were used according to changing the chemical oxygen demand. 13 contaminants were quantified, standing out the endocrine disruptors, lipid regulator and anti-inflammatory. In phase III, 8318.4 ng L^-1 of 4-ocylphenol was found at the influent of the UASB reactor and removal from 1877.1 to 13.7 ng L^-1 in the bisphenol A system. With the maximum organic load, there was a reduction among all the treatment units, with concentrations between 1877.1 and 13.7 ng L^-1 of bisphenol A and had naproxen removal of 94.5% and 2,7 ng L^-1 after treating phases II and III. It was found that 24.6% of the contaminants presented a high ecological risk, with maximum values of 27.4 (4-nonylphenol, phase II), 24.6 and 5.9 (17β-estradiol, phase IV and I, respectively), 13.4 (4-ocylphenol, phase III) and 4.4 (estrone, phase IV) in the influent system. The reduction of ecological risk potentials was optimized by SABF and HSSF-CW. The effect oxygen availability and microbiological activities optimized the reduction of ecological risks on zebrafish (Danio rerio) and cnidarian (Hydra attenuata) species, moreover, the reduction of mass flows and ecological risks of the emerging contaminants are associated with the use of biological reactors in series and organic stabilizations.

Occurrence and assessment of environmental risks of endocrine disrupting compounds in drinking, surface and wastewaters in Serbia

The present study is the first comprehensive monitoring of 13 selected endocrine disrupting compounds (EDCs) in untreated urban and industrial wastewater in Serbia to assess their impact on the Danube River basin and associated freshwaters used as sources for drinking water production in the area. Results showed that natural and synthetic estrogens were present in surface and wastewater at concentrations ranging from 0.1 to 64.8 ng L^-1. Nevertheless, they were not detected in drinking water. For alkylphenols concentrations ranged from 1.1 to 78.3 ng L^-1 in wastewater and from 0.1 to 37.2 ng L^-1 in surface water, while in drinking water concentrations varied from 0.4 to 7.9 ng L^-1. Bisphenol A (BPA) was the most abundant compound in all water types, with frequencies of detection ranging from 57% in drinking water, to 70% in surface and 84% in wastewater. Potential environmental risks were characterized by calculating the risk quotients (RQs) and the estrogenic activity of EDCs in waste, surface and drinking water samples, as an indicator of their potential detrimental effects. RQ values of estrone (E1) and estradiol (E2) were the highest, exceeding the threshold value of 1 in 60% of wastewater samples, while in surface water E1 displayed potential risks in only two samples. Total estrogenic activity (EEQ_t) surpassed the threshold of 1 ng E2 L^-1 in about 67% of wastewater samples, and in 3 surface water samples. In drinking water, EEQ_t was below 1 ng L^-1 in all samples.

Advanced oxidative processes in the degradation of 17β-estradiol present on surface waters: kinetics, byproducts and ecotoxicity

Endocrine disruptors represent risks to aquatic ecosystem and humans, and are commonly detected in surface water. Photochemical treatments can be used to remove 17β-estradiol (E2), but few studies have analyzed the kinetics, intermediates, and 17β-estradiol degradation pathways in natural matrices. In this study, the photochemical behavior of E2 under ultraviolet irradiation (UVC, 254 nm) associated with oxidants (H₂O₂ or O₃) or photocatalyst (TiO₂) was investigated to evaluate the degradation potential and the transformation pathway in a natural surface water matrix. Additionally, computational modeling analyses with Ecological Structure Activity Relationships (ECOSAR) software were performed to predict the toxicity from the E2 and its transformation byproducts. E2 degradation kinetics showed adjusted to the pseudo-first-order kinetic model, being k_UV/O3 > k_UV/TiO2 > k_UV/H2O2 > k_UV. Eight transformation byproducts were identified by liquid chromatography with time-of-flight mass spectrometry (HPLC/TOF-MS) in natural surface water samples. These byproducts formed as the result of opening the aromatic ring and adding the hydroxyl radical. The E2 degradation pathway was proposed based on the byproducts identified in this study and in previous studies, suggesting the formation of aliphatic and hydroxylated byproducts. E2 treatment presented both very toxic and not harmful byproducts.

ELISA as an effective tool to determine spatial and seasonal occurrence of emerging contaminants in the aquatic environment

During the last two decades, studies related to the occurrence and fate of emerging contaminants in the aquatic environment have received great attention from the international scientific community. The monitoring of the presence of these compounds is particularly important since they are known to induce adverse effects in aquatic environments, even at extremely low concentrations. This work aimed to apply a simple and effective methodology, such as enzyme-linked immunosorbent assay (ELISA), in the monitoring of 17α-ethinylestradiol (EE2) and 17β-estradiol (E2) (a synthetic and a natural hormone, respectively), carbamazepine (CBZ, an antiepileptic), cetirizine (CET, an antihistamine) and caffeine (CAF, a stimulant) in water matrices with differing salinity and organic matter contents. ELISA was proven to be a valid and practical tool, especially for screening purposes in contrast to traditional chromatographic techniques which are prohibitively expensive for an application on a broader base. The main originality of this work was to establish seasonal and spatial effects on the occurrence of the referred contaminants by using the effectiveness of ELISA to screen those compounds in samples with different characteristics. This work reports both the seasonal and spatial quantification of the referred contaminants in the aquatic environment of the central region of Portugal, with concentrations ranging as follows: 5-87 ng L-1, for E2, 2-17 ng L-1, for EE2, 10-1290 ng L-1, for CBZ, 10-190 ng L-1, for CET, and 62-6400 ng L-1, for CAF.

Overview of the analysis, occurrence and ecological effects of hormones in lake waters in Asia

Hormones are natural and synthetic compounds that are now being detected in the aquatic environment. Many lakes in Asia are important water sources that may be affected by these emerging contaminants. Lakes are drains and reservoirs of watersheds that are altered by changing land use and environmental conditions. While there are several studies on the detection of hormones in lakes, these studies were mostly done in China. Limited information is available on the presence of these contaminants in the lakes in other Asian countries. Hormones in the lake water come from discharge waters in urban areas, farm runoffs, and effluents of wastewater and sewage treatment plants. Hormones contamination in water has been shown to affect the reproduction and growth of certain aquatic organisms. In this review, a background on the chemical nature and physiological functions of hormones is provided and the existing knowledge on the occurrence and ecological impacts of hormones in lakes is described. The available analytical methods for sampling, analyte extraction and instrumental analysis are outlined. This overview provides insights on the current conditions of lakes that may be impacted by hormones contamination. Understanding the levels and possible ecological consequences will address the issues on these emerging contaminants especially in the Asian environment. This will elicit discussions on improving guidelines on wastewater discharges and will drive future research directions.

Occurrence and fate of androgens in municipal wastewater treatment plants in China

Public concerns about potential ecological risks of androgens discharged to the environment through wastewater treatment plants (WWTPs) has resulted in an increased interest regarding the occurrence and fate of androgens in WWTPs. In this study, the occurrence and removal of eight androgens from 12 municipal WWTPs distributed in eleven cities in China were investigated. The composition profiles of eight androgens in influent, effluent, and excess sludge were studied. Multiple factor analyses were performed to reveal the factors affecting the distribution of androgens in WWTP influent. Results showed similar composition profiles of androgens in the studied WWTPs, with androsterone and dehydroepiandrosterone confirmed as the dominant androgens. The distributions of androgens in WWTP influent were related to the chemical oxygen demand in influent and the gross domestic product (GDP) of WWTP-associated cities. The target androgens have high aqueous removal rates, with a mean removal rate of >90%. Additionally, the behaviors of androgens were evaluated by mass balance along anaerobic-anoxic-oxic (AAO) processes in a WWTP, in which many of the androgens were eliminated mainly in the anaerobic tank. Further, 15 biotransformation products of testosterone were identified under anaerobic, anoxic, and aerobic sludge, respectively. Based on these metabolites, a general biotransformation pathway of testosterone under anaerobic, anoxic, and aerobic sludge is presented.

Quantification of multi-classes of endocrine-disrupting compounds in estuarine water

Emerging pollutants known as endocrine-disrupting compounds (EDCs) are a contemporary global issue, especially in aquatic ecosystems. As aquaculture production through mariculture activities in Malaysia supports food production, the concentration and distribution of EDCs in estuarine water ecosystems may have changed. Therefore, this current study aims to prepare a suitable and reliable method for application on environmental samples. Besides, this study also presented the occurrence of EDCs pollutant in Pulau Kukup, Johor, where the biggest and most active mariculture site in Malaysia takes place. Analytical methods based on a combination of solid-phase extraction with liquid chromatography tandem mass spectrometry (Solid-phase extraction (SPE)-LC-MS/MS) have been modified and optimised to examine the level of targeted EDCs contaminant. In the current study, this method displays high extraction recovery for targeted EDCs, ranging from 92.02% to 132.32%. The highest concentration detected is diclofenac (<0.47-79.89 ng/L) followed by 17β-estradiol (E2) (<5.28-31.43 ng/L) and 17α-ethynylestradiol (EE2) (<0.30-7.67 ng/L). The highest percentage distribution for the targeted EDCs in the current study is diclofenac, followed by EE2 and dexamethasone with the percentages of 99.44%, 89.53% and 73.23%, respectively. This current study can be a baseline assessment to understand the pollution profile of EDCs and their distribution in the estuarine water of the mariculture site throughout the world, especially in Malaysia. Owing to the significant concentration of targeted EDCs detected in water samples, the need for further monitoring in the future is required.