Occurrence and fate of endogenous steroid hormones, alkylphenol ethoxylates, bisphenol A and phthalates in municipal sewage treatment systems

The fate of phthalate acid esters in wastewater treatment plants and their impact on receiving waters

Phthalates (PAEs) are gaining attention and being researched as an endocrine disruptor as global plastic use surge. There is an urgent need to explore the key factors affecting the removal of PAEs from wastewater and the impact of wastewater effluent on receiving water. Here we investigated the levels and distribution patterns of 16 typical PAEs in surface water and five wastewater treatment plants (WWTPs) along the Dongyang River from Yiwu, China, collecting 42 surface water and 31 wastewater samples. We found that influent PAEs concentration and treatment process were the key factors affecting the degradation efficiency of PAEs in primary and secondary treatment, respectively. In primary treatment, long-chain PAEs were more easily removed (and sometimes less likely to accumulate) than short-chain PAEs, regardless of the influent PAEs concentration (a key factor in primary treatment), while in secondary treatment, short-chain PAEs were easily removed regardless of the treatment process (a factor in secondary treatment). This was not the case for long-chain PAEs, which were only more readily removed in the A/A/O process. In addition, by comparing the significant differences between wastewater and surface water, we found that the total PAEs in the treated effluent were significantly lower than in surface water upstream and in built-up urban areas, indicating that wastewater discharges in the study area did not increase PAEs in the receiving water. Finally, river in the city center and artificial treatment facilities in the study area were identified as requiring priority attention. The results of this study can serve as a model for controlling PAEs in other similar developing cities in China and provide valuable information on the fate of endocrine disruptor from wastewater treatment in China and their impact on surface water.

Distribution and source apportionment of phenolic EDCs in rivers in the Pearl River Delta, South China

The sources and distribution characteristics of three phenolic endocrine-disrupting compounds (EDCs), e.g., alkylphenols (APs) (including nonylphenols (NPs) and 4-t-octylphenol (OP)) and Bisphenol A (BPA), were investigated in the rivers of the Pearl River Delta Region (PRDR) with complex land-use types. The mean concentrations of NPs, OP, and BPA in river water including wet and dry seasons were 87, 6, and 74 ng/L in the agricultural regions (n = 10), 135, 7, and 61 ng/L in the transitional regions (n = 8), and 249, 15, and 152 ng/L in the urban regions (n = 28). Contents of NPs and BPA were high in the river sediments (ranged from 7 to 3048 ng/g and 2 to 271 ng/g, respectively). Equilibrium analysis results suggested that sediment release was not the main source of the river EDCs. Principal component analysis (PCA) showed that sewage was the major source of EDCs in the dry season, while the leaching effect of rainfall on the agricultural soils, urban roads, and commercial products was an important source in the wet season. Furthermore, the ratio of APs and total concentration of phenolic EDCs (ΣEDCs) was used to characterize the agricultural regions and urban regions in the PRDR. The ratio was less than 0.6 in the agricultural regions while the ratio was large than 0.6 in the dry season and less than 0.6 in the wet season in urban regions. BPA and NPs in transitional region and urban region had small/medium potential risk to aquatic organisms.

The occurrence, fate, toxicity, and biodegradation of phthalate esters: An overview

Phthalate esters (PAEs) are a class of emerging xenobiotic compounds that are extensively used as plasticizers. In recent times, there has been an increasing concern over the risk of this pervasive pollution exposure causing endocrine disruption and carcinogenicity in humans and animals. The widespread use of PAEs in home and industrial applications has resulted in their discharge in aquatic bodies via leaching, volatilization, and precipitation. In this overview, the current state of PAE pollution, its potential origins, its fate, as well as its effects on the aquatic environment are discussed. A state-of-the-art review of several studies in the literature that focus on the biological degradation of PAEs is included in this study. The paper aims to provide a comprehensive view of current research on PAEs in the environment, highlighting its fate and alleviated risks on the aquatic biotas, their challenges, future prospects, and the need for good management and policies for its remediation. PRACTITIONER POINTS: Occurrence of phthalate esters was summarized in various environmental matrices along with its serious ecotoxicological implications on biota. Wastewater is the prime source of PAEs contamination. Lack of species-specific effects on biota due to dose, exposure route, and susceptibility. The predominant route to mineralization in PAEs is biodegradation. A critical analysis of worldwide PAE production and consumption identifies the necessity for global PAE production, consumption, and release policies.

Screening of antimicrobials, fragrances, UV stabilizers, plasticizers and preservatives in sewage treatment plants (STPs) and their risk assessment in India

Community/industrial wastewater is the prime source of anthropogenic chemicals, its treatment is often a daunting task and unaffordable for many countries. Emerging Contaminants (ECs) have been drained into wastewater after continuous use/misuse and Conventional treatments in STPs do not remove them completely. ECs including antimicrobial agents, synthetic musks, Benzotriazole UV stabilizers (BUVSs), plasticizers, and preservatives are frequently reported in environment, and cause health effects to non-target organisms. Monitoring of ECs is important to understand their status in aquatic environment. Hence, it was aimed to monitor ECs (n = 21) from 11 STPs in Tamil Nadu, India. The detection frequency of most of these analytes was >90%. Antimicrobials ranged from 247 to 22,714 ng/L and 11-14,369 ng/L in influents and effluents, respectively. The synthetic musks were in the order of Tonalide > Galaxolide > Musk Ketone. BUVSs ranged from 4 to 1632 ng/L (influents) and < LOD to 29,853 ng/L (effluents). Concentration of phthalates in influents and effluents were < LOD - 11,311 ng/L and < LOD - 17,618 ng/L, respectively. Parabens were found in the order of Prophyl > Methyl > Ethyl > Butyl in influents and Methyl > Prophyl > Butyl > Ethyl in effluents. Mass loads of ECs through STPs were found as antimicrobials > plasticizers > fragrances > BUVSs > Preservatives. This study reveals increasing usage of ECs and inadequate treatment processes at STPs in India. Also helps to adopt suitable treatment processes to remove ECs from wastewater and to reuse the wastewater.

Spatiotemporal occurrence of phthalate esters in stormwater drains of Hong Kong, China: Mass loading and source identification

Urban stormwater is an important pathway for transporting anthropogenic pollutants to water bodies. Phthalate esters (PAEs) are endocrine disruptors owing to their estrogenic activity and potential carcinogenicity and their ubiquitous presence has garnered global interest. However, their transportation by urban stormwater has been largely overlooked. This study, for the first time, investigated 15 PAEs in stormwater from six major stormwater drains in the highly urbanized Hong Kong, a major metropolitan city in China. The results showed that PAEs were ubiquitous in the stormwater of Hong Kong, with total concentrations (∑₁₅PAEs) spanning from 195 to 80,500 ng/L. Bis(2-n-butoxyethyl) phthalate (DBEP), diisopentyl phthalate (DiPP), dicyclohexyl phthalate (DCHP) and di-n-pentyl phthalate (DnPP) were detected in stormwater for the first time. Spatial variations in PAEs were observed among different stormwater drains, possibly due to the different land use patterns and intensities of human activities in their respective catchments. The highest and lowest levels of ∑₁₅PAEs were found in Kwai Chung (3860 ± 1960 ng/L) and the Ng Tung River (672 ± 557 ng/L), respectively. Additionally, significantly higher concentrations of ∑₁₅PAEs in stormwater were found in the wet season (2520 ± 2050 ng/L) than in the dry season (947 ± 904 ng/L). Principal component analysis classified domestic and industrial origins as two important sources of PAEs in the stormwater of Hong Kong. Stormwater played a crucial role in transporting PAEs, with an estimated annual flux of 0.705-29.4 kg. Thus, possible stormwater management measures were proposed to protect the receiving environment and local ecosystems from stormwater.

A review on the removal of phthalate acid esters in wastewater treatment plants: from the conventional wastewater treatment to combined processes

In the past decades, phthalate acid esters (PAEs), as a new class of recalcitrant environmental contaminant, have attracted increasing concern due to their potential hazards to reproductive system. wastewater treatment plants (WWTPs) are generally regarded as a crucial barrier to prevent a variety of contaminants from introducing into aquatic environment. This paper reviews the occurrence, fate, and removal efficacy of six widely appearing PAEs in conventional wastewater treatment. PAEs removal appears to be compound- and process-dependent. Advanced treatment processes, including activated carbon, advanced oxidation process (AOPs), membrane filtration, and membrane bioreactor, show good performance in PAEs elimination, but many methods have been commercially limited by toxic byproducts, high operation, and maintenance costs. Even though combined processes are qualified as a promising alternative, further studies are required to optimize these processes, especially the competitiveness between technique and economy.

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.

Enhanced periphyton biodegradation of endocrine disrupting hormones and microplastic: Intrinsic reaction mechanism, influential humic acid and microbial community structure elucidation

Endocrine-disrupting compounds (EDCs), as well as microplastics, have drawn global attention due to their presence in the aquatic ecosystem and persistence in wastewater treatment plants (WWTPs). In the present study, for simultaneous bio-removal of two EDCs, 17α-ethinylestradiol (EE2), bisphenol A (BPA), and a microplastic, polypropylene (PP) four kinds of periphytic biofilms were employed. Additionally, the effect of humic acid (HA) on the removal efficacy of these biofilms was evaluated. It was observed that EE2 and BPA (0.2 mg L^-1 each) were completely (∼100%) removed within 36 days of treatment; and the biodegradation of EE2, BPA, and PP was significantly enhanced in the presence of HA. Biodegradation of EE2 and BPA was evaluated through Ultra-high performance liquid chromatography (UHPLC), and Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was used to determine the mechanism of degradation. Gel permeation chromatography (GPC) and SEM had validated the biodegradation of PP (5.2-14.7%). MiSeqsequencing showed that the community structure of natural biofilm changed after the addition of HA, as well as after the addition of EDCs and PP. This change in community structure might be a key factor regarding variable biodegradation percentages. The present study revealed the potential of periphytic biofilms for the simultaneous removal of pollutants of different chemical natures, thus provides a promising new method for wastewater treatment applications.

Combined reverse osmosis and UV/H2O2 treatment of aqueous solutions of bisphenol A and 17α-ethinylestradiol: assessment of estrogenic activity

Bisphenol-A (BPA) and 17α-ethinylestradiol (EE2) are considered endocrine disrupting compounds (EDC) and they may be harmful to the normal functioning of endocrine systems of humans and animals. Moreover, the presence of these compounds in superficial and groundwater may represent serious risks, even in low concentrations like ng·L^-1. The objectives of this study were to remove BPA and EE2 from solutions containing a mixture of these compounds in ultrapure water at low concentrations through reverse osmosis (RO) membrane combined with a UV/H₂O₂ process. Furthermore, to assess the estrogenic activity reduction after such treatments, in vitro recombinant yeast-estrogen screen (YES) assay was used. The removal efficiencies of target micropollutants increased with the increase of H₂O₂ dosage. For RO permeate stream, they enhanced from 91% to 96% for EE2 and from 76% to 90% for BPA while, for the concentrate stream, from 70% to 81% for EE2 and 41% to 84% for BPA as the H₂O₂ concentration were increased from 100 to 1000 µg·L^-1. The OH radicals' generation was the dominant factor in the degradation of EDC during the UV/H₂O₂ treatment since the photolysis itself was not enough to degrade BPA or EE2. The estrogenic activity reduction after UV/H₂O₂ treatment was high, ranging from 92% to 98% for the permeate stream and from 50% to 93% for the concentrate stream. The EE2 was responsible for the whole observed estrogenic activity since BPA does not present estrogenicity, by in vitro YES assay, in the concentrations observed.

17α-ethynylestradiol and its two main conjugates in seven municipal wastewater treatment plants: Analytical method, their occurrence, removal and risk evaluation

This work shows the existence of both 17-ethinylestradiol-3-sulfate (EE2-3S) and 17-ethinylestradiol-3-glucuronide (EE2-3G) in seven municipal WWTPs with substantial concentrations (n.d-50.10 ng/L). The calculated removal efficiencies of 17-ethinylestradiol (EE2) in the seven municipal WWTPs ranged from 40.8%-100% with an average removal efficiency of 83.3%. However, upon the inclusion of EE2 concentration transformed from EE2-3S and EE2-3G, the corresponding removal efficiencies were increased to 91.4%-100% with an average removal efficiency of 97.3%. This work is the first to clearly illustrate that EE2 conjugates in raw wastewater could greatly underestimate the removal effectiveness of municipal WWTPs on EE2, indicating the importance of the EE2 conjugates in municipal wastewater having been hardly paid with attention. The EE2-derived estrogen equivalence (EEQ) values in the effluents of seven WWTPs ranged from 0 to 0.98 ng E2/L having an average level of 0.45 ng E2/L, which were relatively low. However, upon the inclusion of EE2 transformable from EE2-3S and EE2-3G in effluents, the EE2-derived EEQ values in effluents would be increased to 0.77-4.85 ng E2/L having an average level of 2.71 ng E2/L, which clearly suggested that ignorance of EE2 conjugates in effluent would largely underestimate EE2's environmental risk to receiving water bodies.

Phthalate esters in seawater and sediment of the northern South China Sea: Occurrence, distribution, and ecological risks

In this study, the occurrence and distribution of 15 phthalate esters (PAEs) in seawater and sediment from the northern South China Sea (NSCS) were investigated for the first time to improve understanding on the contamination status of PAEs in this region. The concentrations of total PAEs (∑₁₅ PAEs) were found to range from 68.8 to 1500 ng/L, 46.0 to 7800 ng/L, and 49.2 to 440 ng/g dry weight in surface seawater, bottom seawater, and sediment, respectively. Among the 15 PAEs, dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were the predominant PAE congeners, with mean contributions of 44.7% and 24.0% in surface water, and 42.7% and 25.8% in bottom water, respectively. Moreover, diisobutyl phthalate (DiBP) constituted the majority of ∑15 PAEs in the sediment (61.3%). Comparatively high concentrations of Σ15 PAEs were observed in seawater at the sites within the western NSCS, whereas relatively higher concentrations of Σ15 PAEs were detected in sediments at the eastern NSCS. River input and atmospheric deposition could be the main sources of PAEs in the NSCS. Preliminary risk assessment implied that DBP, DiBP, and DEHP posed low to high potential risks for marine organisms at different trophic levels. These results would be valuable for implementing effective control measures and remediation strategies for PAEs contamination in the region.

Occurrence and removal of progestogens from wastewater treatment plants in China: Spatiotemporal variation and process comparison

This study investigated the overall occurrence and spatiotemporal variation of 19 progestogens in 608 samples collected from 17 wastewater treatment plants (WWTPs) distributed across China during four seasons. The aqueous removal efficiencies of progestogens were calculated and the efficacies of process segments, secondary and advanced processes, and process units in the removal of progestogens were explored. The results indicated that progestogens were widely detected in investigating WWTPs, with the progesterone, dydrogesterone, dienogest, ethisterone, and norethindrone were always dominant in the influent, secondary effluent, final effluent, and excess sludge. Seasonally, the influent exhibited more variability than the other matrices, that 10 progestogens concentrations varied significantly during the four seasons. Spatially, the influent concentrations of progestogens were generally higher in northern WWTPs than that in southern WWTPs during spring and summer. Eight progestogens were stably removed by the WWTPs across seasons, and most progestogens varied considerably in removal in different WWTPs. The conventional process segment was the dominant contributor to progestogen removal. The anaerobic-anoxic-oxic process and a combined process consisting of densadeg and cloth media filter and ultraviolet disinfection showed the highest removal of progestogens among various secondary and advanced treatment processes, respectively. Mass balance analysis showed that most progestogens were effectively eliminated in the aerobic unit, with biodegradation being the primary removal pathway. This study presents the first picture of the spatiotemporal dynamics of the distribution of progestogens in WWTPs of China and provides valuable information for better understanding of the occurrence and removal of progestogens in WWTPs.

Interface engineering with self-assembling Au@Ag@β-cyclodextrin bimetal nanoparticles to fabricate a ring-like arrayed SERS substrate for sensitive recognition of phthalate esters based on a host-guest interaction and the coffee ring effect

Herein, Au@Ag@β-cyclodextrin (β-CD) nanoparticles with a relatively uniform shape and size of ∼13 nm in diameter have been successfully synthesized, and the surfaces of the synthesized nanoparticles are successful modified by β-CD. A highly efficient synthetic approach was developed for the preparation of a surface-enhanced Raman spectroscopy (SERS) substrate, which self-assembles Au@Ag@β-CD nanoparticles and analytes into a coffee ring pattern via the coffee ring effect. The coffee ring effect can make phthalates (PAEs) aggregate to the edge together with the Au@Ag@β-CD nanoparticles and concentration enrichment can be achieved. In addition, the surface of the core-shell Au@Ag@β-CD is modified with β-CD with a cavity structure, which can enrich analyte concentration by adsorbing the analytes into the hydrophobic cavity using host-guest recognition. This enrichment process not only improves the concentration of the surface of the analyte but also effectively distinguishes it from other substances in the analyte solution. The mechanism of enrichment and host-guest recognition is verified by subsequent molecular docking simulation. Thus, a ring-like arrayed SERS substrate with dual-strategy enrichment is used to detect PAEs. The experiments using the ring-like arrayed SERS substrate, gave a limit of detection of 0.2 nM for DOP detection, the recovery rate of the spiked samples ranged from 92.3% to 106.6%, and an RSD of less than 6% for PAE detection is obtained. This work provided a simple, rapid, low-cost, highly sensitive and stable method for PAE detection in life and the environment.

Genomic analysis of Gordonia polyisoprenivorans strain R9, a highly effective 17 beta-estradiol- and steroid-degrading bacterium

The increasing levels of estrogens and pollution by other steroids pose considerable challenges to the environment. In this study, the genome of Gordonia polyisoprenivorans strain R9, one of the most effective 17 beta-estradiol- and steroid-degrading bacteria, was sequenced and annotated. The circular chromosome of G. polyisoprenivorans R9 was 6,033,879 bp in size, with an average GC content of 66.91%. More so, 5213 putative protein-coding sequences, 9 rRNA, 49 tRNA, and 3 sRNA genes were predicted. The core-pan gene evolutionary tree for the genus Gordonia showed that G. polyisoprenivorans R9 is clustered with G. polyisoprenivorans VH2 and G. polyisoprenivorans C, with 93.75% and 93.8% similarity to these two strains, respectively. Altogether, the three G. polyisoprenivorans strains contained 3890 core gene clusters. Strain R9 contained 785 specific gene clusters, while 501 and 474 specific gene clusters were identified in strains VH2 and C, respectively. Furthermore, whole genome analysis revealed the existence of the steroids and estrogens degradation pathway in the core genome of all three G. polyisoprenivorans strains, although the G. polyisoprenivorans R9 genome contained more specific estrogen and steroid degradation genes. In strain R9, 207 ABC transporters, 95 short-chain dehydrogenases (SDRs), 26 monooxygenases, 21 dioxygenases, 7 aromatic ring-hydroxylating dioxygenases, and 3 CoA esters were identified, and these are very important for estrogen and steroid transport, and degradation. The results of this study could enhance our understanding of the role of G. polyisoprenivorans R9 in estradiol and steroid degradation as well as evolution within the G. polyisoprenivorans species.

Occurrence, spatial distribution and risk assessment of high concern endocrine-disrupting chemicals in Jiangsu Province, China

Endocrine-disrupting chemicals (EDCs) have attracted much concern because of the environmental and health risks they pose. Here we used liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry to quantify 10 types of EDCs at 118 sampling sites in Jiangsu Province, China, and then evaluated their respective environmental risk using a conservative risk quotient method. The results show that, in surface water, the targeted nonylphenol (NP), 4-tert-octylphenol (4-t-OP), and (2-ethylhexyl)phthalate (DEHP) were ranked highest, having mean concentrations above 300 ng/L. In comparison, both 4-t-OP and DEHP were also ranked highest, with mean concentrations above 100 ng/g, in the sediment samples. Moreover, the ∑₁₀EDCs concentration in the Huai River Basin was similar to that in the Yangtze River Basin. Notably, Huai'an city had the maximum mean concentration for EDCs in the Huai River Basin, followed by Xuzhou city and Suqian city, while Yangzhou city ranked highest in the Yangtze River Basin. Furthermore, the corresponding risk distribution revealed that (1) NP, bisphenol A (BPA), and 4-t-OP are of medium to high risk in 70%, 100% and 95% of the surface water samples, and likewise in 45%, 88% and 100% of the sediment samples, respectively; the maximum RQ value for NP in surface water samples reached 74.9; (2) DEHP belongs to the high-risk category in all samples (100%), whose maximum RQ reached 54.7. To our best knowledge, this is the first study to report on the occurrence, spatial distribution, and risk assessment of EDCs of high concern in Jiangsu Province, China.

The spatiotemporal distribution and potential risk assessment of 19 phthalate acid esters in wastewater treatment plants in China

The spatiotemporal distribution of phthalate acid esters (phthalates, PAEs) in wastewater treatment plants (WWTPs) in China was studied. The concentration of PAEs in influent and effluent increased from 2009 to 2016, indicating that the exposure level of PAEs in China increased continuously. Although the concentration of PAEs in sewage sludge in China ranged from 33.3 to 298 ug/g, there was no obvious spatial distribution pattern. Among the 19 PAE homologues, DEHP, DnBP, and DIBP were the most abundant phthalates detected in wastewater and sludge. Ecological risk assessment confirmed that there was a high chronic and acute risk of DIBP in effluent since 2015. Therefore, this study highlights the need for further studies on the exposure and toxicology of DIBP. Dietary intake accounted for more than 98% of the total risk, indicating that the risk of sludge application in agricultural land was much higher than that in nonagricultural land. The results from this study will provide valuable information for the safe disposal of sludge and wastewater.

A critical review on the distribution and ecological risk assessment of steroid hormones in the environment in China

During past two decades, steroid hormones have raised significant public concerns due to their potential adverse effects on the hormonal functions of aquatic organisms and humans. Considering China being a big producer and consumer of steroid hormones, we summarize the current contamination status of steroid hormones in different environmental compartments in China, and preliminarily assess the associated risks to ecological systems. The results show that steroid hormones are ubiquitously present in Chinese surface waters where estrogens are the most studied steroids compared with androgens, progestogens and glucocorticoids. Estrone (E1), 17β-estradiol (17β-E2) and estriol (E3) are generally the dominant steroid estrogens in Chinese surface waters, whereas for the other steroids, androsterone (ADR), epi-androsterone (EADR), progesterone (PGT), cortisol (CRL) and cortisone (CRN) have relatively large contributions. Meanwhile, the investigations for the other environmental media such as particles, sediments, soils and groundwater have been limited, as well as for steroid conjugates and metabolites. The median risk quotients of most steroid hormones in surface waters and sediments are lower than 1, indicating low to moderate risks to local organisms. This review provides a full picture of steroid distribution and ecological risks in China, which may be useful for future monitoring and risk assessment. More studies may focus on the analysis of steroid conjugates, metabolites, solid phase fractions, analytical method development and acute/chronic toxicities in different matrices to pursue a more precise and holistic risk assessment.

Identification and genome analysis of Comamonas testosteroni strain JLU460ET, a novel steroid-degrading bacterium

In this work, C. testosteroni JLU460ET isolated from animal waste was confirmed to have great degradation capability for 17β-estradiol and testosterone. This bacterium could degrade nearly 90% of 17β-estradiol (5 mg L^-1) in 4 days and transform it into estrone for further degradation. One hundred percent testosterone (144 mg L^-1) could be completely degraded after 9 h of incubation. This is the first report of C. testosteroni strains with the ability to degrade both estrogens and testosterone. The whole genome sequence of C. testosteroni JLU460ET was obtained and annotated, containing one chromosome (5,497,097 bp) with 61.37% GC content. A total of 4805 protein-coding genes and 134 RNA genes (including 29 rRNA genes, 102 tRNA genes and three ncRNA genes) were identified. Furthermore, the complete genome sequence of C. testosteroni JLU460ET was compared with four other C. testosteroni strains. Altogether, these five C. testosteroni strains contain 3508 core genes and 7616 pan genes. A steroid degradation pathway including 11 steroid degradation genes exists in core genes of five C. testosteroni strains. Twenty-two steroid degradation genes were found in the C. testosteroni JLU460ET genome, which has the most reported steroid degradation genes among the five C. testosteroni genomes. Further functional genomic analysis identified a gene cluster responsible for testosterone degradation in C. testosteroni JLU460ET, as well as a gene encoding 17β-HSD, the key enzyme for transforming 17β-estradiol into estrone. This work could enrich the genome sources of steroid-degrading strains and promote the study of steroid-degradation mechanism in bacteria.

Occurrence, Profiles and Ecological Risk of Bisphenol Analogues in a Municipal Sewage Treatment Plant

Due to the strict control on bisphenol A (BPA) in many countries, bisphenol analogues (BPs) are being widely used as alternative materials to manufacture epoxy resins and polycarbonate plastics, resulting in their occurrence in sewage treatment plants (STPs). In this study, the occurrence and distribution of 7 BPs in a large-scale STP in Beijing China was investigated. Wastewater samples were collected from the influents and effluents of each processing unit, and extracted by solid-phase extraction. Target compounds were quantified by ultra-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The total concentrations of seven BPs (ΣBPs) were 400.42 ± 48.12 ng/L in the raw sewage, 438.60 ± 46.50 ng/L in the primary effluent, 17.21 ± 13.12 ng/L in the secondary effluent, and 11.33 ± 4.84 ng/L in the tertiary effluent, respectively. Bisphenol S (BPS) and BPA were the predominant congener in raw sewage with an overall contribution of 29.32% and 70.22% to the ΣBPs, indicating that there was a large amount of BPS and BPA consumption in the study area. During a one-week sampling period, ΣBPs changed slightly at the same sampling site. It was found that high removal efficiencies were achieved for BPs in anoxic and oxic secondary clarifier treatment units, suggesting that biodegradation and sorption played major roles in BPs elimination in the STP. After tertiary treatment, all BPs except BPA were completely removed, suggesting the necessity to investigate the fate and toxicity of BPA in the aquatic environment.

Quantification, distribution, and effects of di (2-ethylhexyl) phthalate contamination: Risk analysis and mitigation strategies in urban environment

Phthalate acid ester, di (2-ethylhexyl) phthalate (DEHP) is ubiquitously detected contaminant of emerging concerns (CECs) in all the environmental samples. The present study attempted to understand the fate and transport of DEHP in urban areas by evaluating the quantities, distribution, risk, and effects in the Mysuru city, India. The study is anticipated to serve as a vital document for local and national regulators to frame a robust DEHP management plan and mitigate the risks associated. Liquid-liquid microextraction followed by gas chromatographic analysis was adopted to determine the concentrations of DEHP. The risk quotient method was adopted to assess potential risk, and a conceptual planning model framework was designed to mitigate the DEHP contamination. The municipal wastewater contained 115 ± 9.2 μg/L, whereas treated municipal wastewater showed 95 ± 7.6 μg/L DEHP that was attributed to the inefficiency of the treatment plant. Further, sediments in surface water, as well as groundwater samples of the study area, showed 8 ± 0.64 to 12 ± 0.96 μg/L and 32 ± 2.56 to 40 ± 3.2 μg/kg of DEHP, respectively. The risk quotient of 19.17 for samples in around treatment indicated highest risk, whereas groundwater samples had a risk quotient of 1-2 indicating relative risk to aquatic organisms. In addition, the study highlighted the source, possible entry pathways, and management strategies including treatment aspects to draw an understanding of the distribution and potential ecological imbalances with contamination of DEHP in the urban sector. PRACTITIONER POINTS: Understand the fate and transportation of DEHP in urban wastewater. Primary investigation and assessment to possible health and environmental risks of DEHP contamination in urban wastewater. Revealed the associated health risks and proposed possible management strategies.

Simultaneous determination of low molecule benzotriazoles and benzotriazole UV stabilizers in wastewater by ultrasound-assisted emulsification microextraction followed by GC-MS detection

A rapid, sensitive, economically and ecologically friendly method based on one-step ultrasound-assisted emulsification microextraction and in situ derivatization followed by gas chromatography-mass spectrometry for simultaneous determination of low molecular benzotriazoles and benzotriazole-based ultraviolet filters was developed. The optimized method allows quantification of benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole; 5-chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzortriazole and 2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole in municipal and industrial (dairy) wastewater. The method was validated using real influent and effluent wastewater and samples at various stages of the purification process. Relative recoveries obtained using wastewater as sample matrix were between 77 and 137%, method limits of detection from 0.001 to 0.035 µg/L, method limits of quantification from 0.003 to 0.116 µg/L, the repeatability expressed by the coefficient of variation did not exceed 12%. The use of the method for the determination of tested compounds in municipal and industrial wastewater showed their presence in most of the tested samples, in concentrations from LoD to 6.110 µg/L. The conducted studies of samples from municipal wastewater treatment plant located in north-east Poland showed that the effectiveness of benzotriazole removal by this plant wasfrom 29 to 84%. The load of tested compounds released into the environment by this facility ranges from 2 to 269 mg/day/1000 inhabitants.

Combined cytotoxicity of polystyrene nanoplastics and phthalate esters on human lung epithelial A549 cells and its mechanism

Awareness of risks posed by widespread presence of nanoplastics (NPs) and bioavailability and potential to interact with organic pollutants has been increasing. Inhalation is one of the more important pathways of exposure of humans to NPs. In this study, combined toxicity of concentrations of polystyrene NPs and various phthalate esters (PAEs), some of the most common plasticizers, including dibutyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) on human lung epithelial A549 cells were investigated. When co-exposed, 20 μg NPs/mL increased viabilities of cells exposed to either DBP or DEHP and the modulation of toxic potency of DEHP was greater than that of DBP, while the 200 μg NPs/mL resulted in lesser viability of cells. PAEs sorbed to NPs decreased free phase concentrations (C_free) of PAEs, which resulted in a corresponding lesser bioavailability and joint toxicity at the lesser concentration of NPs. The opposite effect was observed at the greater concentration of NPs, which may result from the dominated role of NPs in the combined toxicity. Furthermore, our data showed that oxidative stress and inflammatory reactions were mechanisms for combined cytotoxicities of PAEs and NPs on A549 cells. Results of this study emphasized the combined toxic effects and mechanisms on human lung cells, which are helpful for assessing the risk of the co-exposure of NPs and organic contaminants in humans.

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.

Recent Advances in the Rejection of Endocrine-Disrupting Compounds from Water Using Membrane and Membrane Bioreactor Technologies: A Review

Water is a critical resource necessary for life to be sustained, and its availability should be secured, appropriated, and easily obtainable. The continual detection of endocrine-disrupting chemicals (EDCs) (ng/L or µg/L) in water and wastewater has attracted critical concerns among the regulatory authorities and general public, due to its associated public health, ecological risks, and a threat to global water quality. Presently, there is a lack of stringent discharge standards regulating the emerging multiclass contaminants to obviate its possible undesirable impacts. The conventional treatment processes have reportedly ineffectual in eliminating the persistent EDCs pollutants, necessitating the researchers to develop alternative treatment methods. Occurrences of the EDCs and the attributed effects on humans and the environment are adequately reviewed. It indicated that comprehensive information on the recent advances in the rejection of EDCs via a novel membrane and membrane bioreactor (MBR) treatment techniques are still lacking. This paper critically studies and reports on recent advances in the membrane and MBR treatment methods for removing EDCs, fouling challenges, and its mitigation strategies. The removal mechanisms and the operating factors influencing the EDCs remediation were also examined. Membranes and MBR approaches have proven successful and viable to eliminate various EDCs contaminants.

Occurrence, removal, and environmental risk of phthalates in wastewaters, landfill leachates, and groundwater in Poland

Phthalates or phthalic acid esters (PAEs) are chemical compounds whose use is exceptionally widespread in everyday materials but, at the same time, have been proven to have harmful effects on living organisms. Effluents from municipal wastewater treatment plants (WWTP) and leachates from municipal solid waste (MSW) landfills are important sources of phthalates with respect to naturally occurring waters. The main aim of this research was determination, mass loads, removal rates and ecological risk assessment of eight phthalates in municipal wastewaters, landfill leachates and groundwater from Polish WWTPs and MSW landfills. Solid-phase microextraction and gas chromatography with mass spectrometry were used for the extraction and determination of analytes. Summed up concentrations of eight phthalates ranged from below LOD to 596 μg/L in influent wastewater with the highest concentration found for bis-2-ethylhexyl phthalate (DEHP) (143 μg/L). The average degree of phthalate removal varies depending on the capacity of a given treatment plant with larger treatment plants coping better than smaller ones. The highest treatment efficiency for all tested treatment plants, over 90%, was reported for dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall concentrations of phthalates in leachates ranged from below LOD to 303 μg/L while the highest maximum concentration was registered for DEHP (249 μg/L). Overall concentrations of phthalic acid esters in groundwater from upstream monitoring wells ranged from below LOD to 1.8 μg/L and from LOD to 27.9 μg/L in samples from wells downstream of MSW landfills. The obtained data shows that diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), DEHP, and diisononyl phthalate (DINP) pose a high risk for all trophic levels being considered in effluent wastewaters. In the case of groundwater high environmental risk was recorded for DBP and DEHP for all tested trophic levels. Phthalates, in concentrations that pose a high environmental risk, are present in Polish municipal after-treatment wastewater as well as in groundwater under municipal solid waste landfills.

Influence of humic acids on fungal laccase-initiated 17α-ethynylestradiol oligomerization: Transformation kinetics and products distribution

Fungal laccase has aroused great concern in rapidly removing estrogens because of its ability to accelerate humification and oligomerization. Here, the effect of two humic acids (HAs) on the reaction kinetics and products distribution of 17α-ethynylestradiol (EE2) in laccase-initiated humification and coupling was systematically elucidated. Laccase from Trametes versicolor exhibited over 98.3% removal rate for EE2 at pH 5.0 within 120 min, while HAs invariably restrained EE2 transformation by competing with target-substrate for the enzymatic catalytic center. EE2 removal followed pseudo-first-order kinetics, and the rate constant was decreased markedly with increasing concentration of two HAs (0-60 mg L^-1). Additionally, laccase heightened the aromaticity and humification degrees (A_{250 nm}/A_{365 nm} ratio) of HAs probably due to the formation of new humic polymers such as (HA)_m and/or (HA)_m-(EE2)_n (m and n represent the number of HA and EE2 units, respectively). Three major EE2 oligomers were identified, in accordance with a mechanism involving the phenoxy radical-driven polymerization to yield a wide variety of self-coupling products. Notably, HAs diminished the extent of EE2 self-coupling but aggrandized the cross-coupling between EE2 and HAs, and the inhibition degree of EE2 self-coupling increased with the concentration of HAs. One major reason is EE2 could be covalently incorporated into humic molecules to produce (HA)_m-(EE2)_n cross-coupling products via radical-caused C-C, C-O-C, and/or C-O-C bonds, thereby reducing EE2 self-oligomerization. These findings highlight that HAs play a vital role in the fungal laccase-induced humification and oligomerization of EE2, which obviously alter the geochemical fate and transport of EE2 in natural aquatic ecosystems.

Trace determination of eleven natural estrogens and insights from their occurrence in a municipal wastewater treatment plant and river water

As endocrine disruptors, natural estrogens including estrone (E1), 17β-estradiol (E2), and estriol (E3) in wastewaters of municipal wastewater treatment plant (WWTP) as well as other environmental matrix have been widely studied. However, the far-less studied natural estrogens such as 2-hydroxyestrone (2OHE1), 16α-hydroxyestrone (16α-OHE1), 4-hydroxyestrone (4OHE1), etc., found in human urine have been almost ignored. Therefore, it is important to investigate the occurrence of these far-less studied natural estrogens in municipal WWTP and other environment. In this study, a GC-MS analytical method was firstly established and validated for trace determination of eleven natural estrogens in waste and surface waters, including E1, E2, E3, 2OHE1, 16α-OHE1, 4OHE1, 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 17-epiestriol (17epiE3), 16-epiestriol (16epiE3), and 16keto-estradiol (16ketoE2). All the eleven natural estrogens were detected in the influent of one municipal WWTP, which ranged from 7.9 to 62.9 ng/L. The top five natural estrogens in the influent were E1, E3, 16α-OHE1, 16ketoE2, and 2OHE1 with respective concentrations of 62.9, 62.6, 46.9, 32.7, and 28.8 ng/L. Most of them were detected in both the effluent and river water, in which their detected concentrations were n.d-14.7 and n.d-51.7 ng/L, respectively. This work is the first to indicate that the so far less commonly studied natural estrogens in the environment likely pose adverse health effect on humans and wildlife due to their relative strong estrogenic potencies and high levels in wastewater and river water. More work should be done to understand their removals in municipal WWTPs and their occurrence in surface waters.

Determination of Endocrine Disrupting Chemicals in Water and Wastewater Samples by Liquid Chromatography-Negative Ion Electrospray Ionization-Tandem Mass Spectrometry

A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was developed for the simultaneous analysis of bisphenol A, 4-octylphenol, 4-nonylphenol, diethylstilbestrol, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, prednisone, and prednisolone. This method used solid-phase extraction with an elution solvent of acetonitrile to improve the stability of the analytes. To maintain the stability of analytes analyses were completed within five days. The recoveries ranged from 84 to 112% and the relative standard deviation of analysis of duplicate samples was <10%. The limits of quantitation were 1–10 ng/L. Surface water and wastewater were obtained from five wastewater treatment plants in Saskatchewan. Matrix effects were moderate to severe. Using standard addition calibration, all analytes except diethylstilbestrol and 17α-ethinyl estradiol were detected. There was a low frequency of detection of the target analytes in upstream and downstream water, indicating good removal efficiency during the wastewater treatment process. Bisphenol A and 4-nonylphenol were the only analytes detected downstream. Bisphenol A was the most frequently detected in raw wastewater (133 to 403 ng/L). Estriol was detected more often in raw wastewater than estrone or 17β-estradiol. This is the first Canadian study with the detection of prednisone and prednisolone with concentrations at 198–350 ng/L in raw wastewater at 60% of the wastewater treatment plants.

Adsorption-desorption behavior of the endocrine-disrupting chemical quinestrol in soils

Quinestrol (QUN), a synthetic estrogen used as an oral contraceptive or emergency contraceptive component, has been shown to be an endocrine-disrupting chemical. To assess the environmental risk of QUN, batch equilibration experiments were conducted to investigate the adsorption–desorption of QUN in five contrasting soils from different areas of China. The leaching properties were also calculated based on the adsorption and degradation data from our previous study with the same soils. The Freundlich and Langmuir models were applied to the sorption–desorption data to examine the affinity towards QUN of the soils, which had varying physical and chemical properties. The K_f and K_f^des values of QUN in the tested soils ranged from 3.72 to 20.47 mg¹⁻ⁿ Lⁿ kg⁻¹ and from 1.26 to 7.8 mg¹⁻ⁿ Lⁿ kg⁻¹, respectively, and Q_m ranged from 28.25 to 126.58 mg/kg. The desorption data showed that hysteresis occurred. The K_f and K_f^des values of QUN were positively correlated with the soil total organic carbon (OC) and cation exchange capacity (CEC), and it may be due to the content of TOC and CEC exhibited a positive correlation. A low mobility potential of QUN in soils was predicted and verified the adsorption results by the groundwater ubiquity score (GUS) and retardation factor (R_f).

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.

Isolation and characterization of a new highly effective 17β-estradiol-degrading Gordonia sp. strain R9

In this report, Gordonia sp. strain R9 isolated from an enrichment culture of chicken leachate was confirmed to degrade 17β-estradiol (E2), which can also use other estrogens (estrone, estriol, and 17α-ethynylestradiol) and testosterone as sole carbon and energy sources. Optimization of growth conditions showed that Gordonia sp. strain R9 can tolerate a very wide range of temperature (4-40 °C) and pH (1.0-11.0), and is sensitive to antibiotics including kanamycin, ampicillin, chloramphenicol, and carbenicillin. Optimal culture conditions for E2 degradation were 30 °C and pH 7.0 with almost 100% degradation of E2 concentrations ranging from 50 µg/L to 5 mg/L within 24 h. The E2 intermediates so generated included estrone (E1), estratriol (E3), (3Z)-3-(3-hydroxy-3a-methyl-7-oxododecahydro-6H-cyclopenta[a]naphthalen-6-ylidene) propanoic acid and 3-hydroxy-3a-methyl-7-oxododecahydro-1H-cyclopenta[a]naphthalene-6-carboxylic acid. These results indicate that the highly effective E2-degradative ability of Gordonia sp. strain R9 merits further investigation as a candidate for large-scale estrogen biodegradation.

Efficacy assessment of peracetic acid in the removal of synthetic 17α-ethinyl estradiol contraceptive hormone in wastewater

Increasing concerns have been raised on endocrine disrupting chemicals like the sex hormone 17α-ethinylestradiol (EE2), the more since traditional wastewater (WW) treatments appear to be ineffective for their removal. The efficacy of the relatively novel disinfectant peracetic acid (PAA) in EE2 removal was evaluated, as well as its potential effects on WW quality parameters. The treatments tested for EE2 removal were also evaluated in terms of toxicity, through the determination of biochemical responses (antioxidant enzymes, lipid peroxidation and vitellogenin induction) using zebrafish (Danio rerio) as a biological model. PAA contact times less than 20 min appeared insufficient regardless of the PAA dose tested, but a 100% EE2 removal was attained at a PAA concentration of 15 mg/L with a contact time of 20 min. Total suspended solids, chemical oxygen demand and pH in PAA treatments remained well within levels set in European legislation for WW discharge. EE2 induced significant increased vitellogenin (VTG) levels in both female and male fish, indicating increased estrogenic activity, especially in males suggesting an endocrine disruption effect. With the addition of PAA (15 mg/L), however, VTG levels in both sexes returned to control values. Although this PAA treatment showed increased levels of the antioxidant enzyme catalase, the lipid peroxidation levels were similar or even lower than in controls. Overall the results suggest that the use of PAA appears a promising way forward as a less toxic alternative to chlorine disinfection with high efficiency in the removal of EDC like EE2.

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.

Nanomaterials as alternative dispersants for the multiresidue analysis of phthalates in soil samples using matrix solid phase dispersion prior to ultra-high performance liquid chromatography tandem mass spectrometry

In this study, the application of different nanomaterials as dispersants in matrix solid phase dispersion has been evaluated for the extraction of fifteen phthalates from different environmental samples prior to their separation and quantification by ultra-high performance liquid chromatography coupled to triple quadrupole mass spectrometry. Within the evaluated nanomaterials, including graphene oxide, multi-walled carbon nanotubes and iron 1,3,5-benzenetricarboxylate metal-organic framework, the last one showed the best results in terms of extraction capacity and sample clean-up. The effects of the different parameters affecting the sample pretreatment efficiency were exhaustively evaluated. The whole methodology was validated for agricultural soil and sand, using dibutyl phthalate-3,4,5,6-d₄ as surrogate. Recovery values ranged from 70 to 120% for both matrices with RSD values lower than 20% and the limits of quantification of the method achieved were in the range 0.14-2.7 μg/kg dry weight. Finally, the analysis of soil samples from different locations of Tenerife (Canary Islands, Spain) was carried out finding the presence of BBP, DIBP and DBP in the range 5-52 μg/kg dry weight in agricultural soils, and DIPP, DNOP and DINP in the range 2-101 μg/kg dry weight in sand samples.

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.

Insights into removal mechanisms of bisphenol A and its analogues in municipal wastewater treatment plants

The occurrence and removal mechanisms of bisphenol A (BPA) and its analogues in municipal WWTPs were critically reviewed in this article. BPA appeared to be the dominant bisphenol, and the removal efficiency of bisphenols was in the order of bisphenol AP>bisphenol P>bisphenol F>bisphenol Z>bisphenol C>bisphenol S>bisphenol B>BPA>bisphenol E>bisphenol AF. It was also found that BPA removal showed linear relationships to those of its analogues, which have been proven by BPA vs BPS or BPF. BPA removal performances in different treatment processes ranked from low to high are primary treatment, lagoon process, biological aerated filter, and activated sludge. Lab-scale studies showed that >50% BPA can be removed by sewage sludge estimated with the BPA solid water distribution coefficients, which showed that sludge adsorption played an important role on BPA removal. The theoretically predicted removal of BPA in municipal WWTP showed that it is readily biodegradable, which deviate from its on-site investigations. Existence of BPA conjugates in raw municipal wastewater as well as newly produced BPA degraded or migrated from microplastic materials are possible two main reasons.

Occurrence, fate and risk assessment of BPA and its substituents in wastewater treatment plant: A review

Several bisphenol analogues (BPs) are gradually replacing bisphenol A (BPA) in many fields, following strict restrictions on the production and use of BPA. The presence of micropollutants in wastewater treatment plants (WWTPs) may pose risks to the aquatic ecosystem and human health. In this review, we outlined the occurrence and fate of BPs in WWTPs, and estimated their potential risks to the aquatic ecosystem. BPA is still the most predominant bisphenol analogue in WWTPs with high detection rate and concentration, followed by bisphenol S (BPS) and F (BPF). Biodegradation and adsorption are the main removal pathways for removal of BPs in WWTPs. The secondary (activated sludge process, biological aerated filter, and membrane bioreactor) and advanced (membrane technique, ultraviolet disinfection, adsorption process, and ozonation) treatment processes show high removal efficiency for BPs, which are influenced by many factors such as sludge retention time and redox conditions. BPs other than BPA (assessed in this review) in effluent of WWTPs have low risks to Daphnia magna and early life stages on medaka, while BPA shows a medium or high risk under certain conditions. Knowledge gaps have been identified and future line of research on this class of chemicals in WWTPs is recommended. More data are needed to illustrate the occurrence and fate of BPs in WWTPs. Environmental risks of BPs other than BPA initiating from wastewater discharge to aquatic organisms remain largely unknown.

Post-aerobic treatment to enhance the removal of conventional and emerging micropollutants in the digestion of waste sludge

Low content of micropollutants in sewage sludge, essential to allow its safe re-use in agriculture, requires effective removals during the digestion phase. To this purpose, we investigated the performance of the anaerobic-aerobic sequential digestion process applied to real waste sludge in the removal of several classes of standard pollutants, i.e. extractable organic halogens (EOXs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), di(2-ethylhexyl)phthalate and alkylphenolethoxylates. In addition, emerging pollutants were also investigated based on their widespread occurrence and on their physicochemical characteristics and eco-toxicological relevance: quaternary ammonium compounds, a number of pharmaceuticals and selected biocides. The anaerobic step was conducted at mesophilic conditions, while two operating temperatures were tested for the post-aerobic treatment, i.e. 20 and 37 °C, respectively. Results showed that the post-aerobic digestion step enhanced the removal of all investigated standard and emerging micropollutants, even in presence of high accumulation in the anaerobic digestate (occurred for some PAHs and PCB congeners). Increased removals (up to 30%) have been generally observed at 37 °C aerobic temperature in comparison with tests at T = 20 °C for all investigated organic micropollutants, with the only exception of halogenated compounds (i.e. EOXs and PCBs). Low biodegradability and high bioaccumulation of the investigated pollutants were successfully faced by the sequential process, which has been demonstrated as an effective alternative solution to produce digested sludge for safe agricultural re-use.

Occurrence and removal of progestagens in municipal wastewater treatment plants from different regions in China

Progestagens discharged from municipal wastewater treatment plants (WWTPs) have increasingly gained attention due to their potential risks to the aquatic organisms. However, limited information is available on the occurrence and removal of various progestagens in WWTPs in different cities of China. This work investigated the occurrence and removal of 11 progestagens in 21 WWTPs from 19 Chinese cities. Results showed that progestagens are widely distributed in the investigated WWTPs, with higher influent concentrations of total progestagens in northern WWTPs. The concentration of progestagens in WWTP influent were closely correlated with influent quality, service population and daily service volume of the WWTPs. Additionally, progesterone (PGT) and dydrogesterone (DDT) were two predominant progestagens in influent, effluent and excess sludge. Up to 5 of 11 progestagens showed high aqueous removal efficiencies (median removal efficiency >90%), whereas megestrol acetate (MTA), chlormadinone acetate (CMA), drospirenone (DSP) and levonorgestrel (LNG) had a removal efficiency of below 50%. Specially, the behaviors of progestagens along the anaerobic-anoxic-oxic of a WWTP were further explored and the aerobic tank is the main contributor to the removal of progestagens. Finally, in the effluent of these 21 WWTPs, daily mass loadings of the total progestagens ranged from 0.51 to 10.4 g d^-1. Notably, LNG exhibited high potential risk to the fish base on risk quotient.

What you extract is what you see: Optimising the preparation of water and wastewater samples for in vitro bioassays

The assessment of water quality is crucial for safeguarding drinking water resources and ecosystem integrity. To this end, sample preparation and extraction is critically important, especially when investigating emerging contaminants and the toxicity of water samples. As extraction methods are rarely optimised for bioassays but rather adopted from chemical analysis, this may result in a misrepresentation of the actual toxicity. In this study, surface water, groundwater, hospital and municipal wastewater were used to characterise the impacts of common sample preparation techniques (acidification, filtration and solid phase extraction (SPE)) on the outcomes of eleven in vitro bioassays. The latter covered endocrine activity (reporter gene assays for estrogen, androgen, aryl-hydrocarbon, retinoic acid, retinoid X, vitamin D, thyroid receptor), mutagenicity (Ames fluctuation test), genotoxicity (umu test) and cytotoxicity. Water samples extracted using different SPE sorbents (Oasis HLB, Supelco ENVI-Carb+, Telos C18/ENV) at acidic and neutral pH were compared for their performance in recovering biological effects. Acidification, commonly used for stabilisation, significantly altered the endocrine activity and toxicity of most (waste)water samples. Sample filtration did not affect the majority of endpoints but in certain cases affected the (anti-)estrogenic and dioxin-like activities. SPE extracts (10.4 × final concentration), including WWTP effluents, induced significant endocrine effects that were not detected in aqueous samples (0.63 × final concentration), such as estrogenic, (anti-)androgenic and dioxin-like activities. When ranking the SPE methods using multivariate Pareto optimisation an extraction with Telos C18/ENV at pH 7 was most effective in recovering toxicity. At the same time, these extracts were highly cytotoxic masking the endpoint under investigation. Compared to that, extraction at pH 2.5 enriched less cytotoxicity. In summary, our study demonstrates that sample preparation and extraction critically affect the outcome of bioassays when assessing the toxicity of water samples. Depending on the water matrix and the bioassay, these methods need to be optimised to accurately assess water quality.

Ameliorative effect of Silybin on bisphenol A induced oxidative stress, cell proliferation and steroid hormones oxidation in HepG2 cell cultures

Bisphenol A (BPA) and silybin are considered xenoestrogens and could interfere with the action of endogenous hormones. It was demonstrated a higher level of BPA in plasma of nonalcoholic steatohepatitis (NASH) patients, compared to those with steatosis (NAFL). We investigated the effect of BPA and silybin, alone or in combination, on proliferation, oxidative stress and steroid metabolism in HepG2 grown in high glucose concentration medium (H-HepG2). Cell viability was assessed by adding 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). TBARS were quantified by spectrophotometry. The effect of BPA, silybin and their combination on the expression of phosphorilized extracellular signal-regulated kinase (ERK), ERK and Caspase 3 was determined by Western blot analysis. The identifications of lipids and steroid hormones was performed by mass spectrometry. BPA elicited in H-HepG2 oxidative stress and steroid hormones oxidation leading to the formation of metabolite with estrogenic and genotoxic potentials. Silybin ameliorates the harmful BPA-induced effect decreasing glucose uptake and lipid peroxidation. Moreover silybin activates the synthesis of vitamin D3 metabolites and prevent the steroid hormones oxidation. BPA could be considered as an important risk factor in worsening and progression of NAFLD. At the same time silybin could be a valid support to counteract these effects in NASH patients.

Seasonal occurrence and fate of chiral pharmaceuticals in different sewage treatment systems in Hong Kong: Mass balance, enantiomeric profiling, and risk assessment

Concern about the presence of chiral pharmaceuticals in the environment from wastewater discharge is mounting. In this work, the occurrence and fate of atenolol, metoprolol, venlafaxine, and chloramphenicol, including 10 different stereoisomers, were investigated in sewage and sludge from diverse treatment processes in 4 sewage treatment plants (STPs) in Hong Kong via 4 sampling campaigns over a period of 2 years. The average amounts of individual pharmaceuticals entering the STPs ranged from 4.91 g/d to 6290 g/d, with sludge carrying much lower amounts than the discharged effluent. Mass balance analysis revealed that: larger quantities of these pharmaceuticals were released during the dry seasons, biodegradation was the primary removal mechanism for atenolol and chloramphenicol, and the removal via primary sedimentation and disinfection processes was insignificant (<30%). Selectivity toward R-(+)-atenolol, S-(-)-metoprolol, and R-(-)-venlafaxine was mostly found across secondary-treated effluent samples. Sold as an enantiopure pharmaceutical in R,R-para-form, chloramphenicol was preferentially eliminated after biological process. This is the first study on the occurrence of chloramphenicol enantiomers in the aquatic environment. Ecotoxicological assessment indicated that atenolol and metoprolol could pose risks to marine fish in effluent-receiving waters (i.e., the western waters and Victoria Harbor) of Hong Kong, while R-(+)-atenolol could pose a risk to protozoans five times higher than the S-(-)-enantiomer.

17β-Estradiol residues and estrogenic activities in the Hawkesbury River, Australia

Two highly sensitive ELISAs for the specific detection of 17β-estradiol (E2) residues were developed, showing the limits of detection (LOD, a concentration at 15% inhibition of color development) of 0.04 ± 0.02 μg/L and 0.05 ± 0.03 μg/L. The average recovery rate of the river water samples spiked with E2 at 1-50 ng/L range was 111.5% (68.6-252%) with the % relative standard deviation (RSD) of 0.5-86.3%. The ELISA demonstrated a good correlation with the GC-MS analyses of the spiked river water samples (r = 0.909). Applying the developed E2 ELISA assay to the monitoring of E2 residues in Hawkesbury River (New South Wales, Australia) found that all the tested creek samples contained E2 residues less than the biologically significant level of 10 ng/L. However, 25% of the water samples tested demonstrated the estrogen activity (determined by the yeast estrogen screening (YES) assay) above the levels that have been linked to the adverse effects in fish and other aquatic organisms (> 20 E2 Eq ng/L). It was apparent that the E2 residues together with the EE2 residues (reported in our previous study) contributed to most of the observed estrogenic activity in Hawkesbury River.

Roles of membrane and organic fouling layers on the removal of endocrine disrupting chemicals in microfiltration

To understand the adsorption behavior of endocrine disrupting chemicals (EDCs) is important for enhancing the treatment performance and preventing potential secondary pollution caused by EDCs desorption in a microfiltration system. The dynamic adsorption of four representative EDCs, namely estriol (E3), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), and 4-nonylphenol (4-NP) in a microfiltration system was investigated using the Thomas' model. The product of the equilibrium constant and the total adsorption capacity of the membrane, Ka, for E3, E2, EE2, and 4-NP were 4.91, 9.78, 15.6, and 826, respectively, strongly correlating with the compound octanol-water partition coefficient (K_OW). Adsorption appeared to be enhanced when organic fouling formed on the surface of membrane, indicating the role of an additional adsorption column for EDCs acted by a fouling layer in microfiltration. Results of a comparison between the Ka values for clean membrane and fouled membrane illustrated that the significant contribution made by fouling layers may be attributed to the foulant layer's hydrophobicity (in the case of calcium humate layer) and thickness (in the case of calcium alginate layer). This study provided a novel perspective to quantitatively analyze the dynamic adsorption behavior of trace pollutants in membrane process.

Simultaneous quantitative monitoring of four indicator contaminants of emerging concern (CEC) in different water sources of Central India using SPE/LC-(ESI)MS-MS

Environmental occurrence of CECs poses a great threat to both aquatic life and human health. The aim of this study was to optimize and validate SPE/LC-(ESI)MS-MS method for simultaneous quantitative monitoring of two sub-classes of CECs (pharmaceuticals and hormones) and to estimate the concentrations of select CECs in environmental water samples. For all the tested analytes, recoveries in laboratory reagent water were greater than 81%. Average percent (relative standard deviation) RSD of the analytes in recovery, repeatability, and reproducibility experiments were ≤ 10%. Determination coefficients (r²) of primidone, diclofenac, testosterone, and progesterone were estimated to be 0.9979, 0.9972, 0.9968, and 0.9962, respectively. Limits of detection (LOD) for primidone, diclofenac, testosterone, and progesterone were 4.63 ng/L, 5.36 ng/L, 0.55 ng/L, and 0.88 ng/L, respectively. Limits of quantification (LOQ) for primidone, diclofenac, testosterone, and progesterone were 14.72 ng/L, 17.06 ng/L, 1.766 ng/L, and 2.813 ng/L, respectively. Average recoveries in environmental water and wastewater samples were greater than 74% and RSD were ≤ 7%. Trace levels (68.33-125.70 ng/L) of primidone were detected in four environmental water samples, whereas diclofenac was not detected in any of the tested sample. Trace levels of progesterone were observed in two environmental samples (16.64 -203.73 ng/L), whereas testosterone was detected in STP inlet sample (178.16 ng/L).

Monitoring of 943 organic micropollutants in wastewater from municipal wastewater treatment plants with secondary and advanced treatment processes

To perform a systematic survey on the occurrence and removal of micropollutants during municipal wastewater treatment, 943 semi-volatile organic chemicals in 32 wastewater samples including influents of secondary treatments, secondary effluents and final effluents (effluents of advanced treatments), which were collected from seven full-scale municipal wastewater treatment plants (MWTPs) in China, were examined by gas chromatography-mass spectrometry (GC-MS) coupled with an automated identification and quantification system with a database (AIQS-DB). In total, 196 and 145 chemicals were detected in secondary and final effluents, respectively. The majority of the total concentrations (average removal efficiency, 87.0%±5.9%) of the micropollutants were removed during secondary treatments. However, advanced treatments achieved different micropollutant removal extents from secondary effluents depending on the different treatment processes employed. Highly variable removal efficiencies of total concentrations (32.7%-99.3%) were observed among the different advanced processes. Among them, ozonation-based processes could remove 70.0%-80.9% of the total concentrations of studied micropollutants. The potentially harmful micropollutants, based on their detection frequency and concentration in secondary and final effluents, were polycyclic aromatic hydrocarbons (PAHs) (2-methylnaphthalene, fluoranthene, pyrene, naphthalene and phenanthrene), phosphorus flame retardants (tributyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP) and tris(1,3-dichloro-2-propyl) phosphate (TDCP)), phthalates (bis(2-ethylhexyl)phthalate (DEHP)), benzothiazoles (benzothiazole, 2-(methylthio)-benzothiazol, and 2(3H)-benzothiazolone) and phenol. This study indicated that the presence of considerable amounts of micropollutants in secondary effluent creates the need for suitable advanced treatment before their reuse.