Nonylphenol ethoxylates biodegradation increases estrogenicity of textile wastewater in biological treatment systems

Chemical-toxicological insights and process comparison for estrogenic activity mitigation in municipal wastewater treatment plants

Efforts in water ecosystem conservation require an understanding of causative factors and removal efficacies associated with mixture toxicity during wastewater treatment. This study conducts a comprehensive investigation into the interplay between wastewater estrogenic activity and 30 estrogen-like endocrine disrupting chemicals (EEDCs) across 12 municipal wastewater treatment plants (WWTPs) spanning four seasons in China. Results reveal substantial estrogenic activity in all WWTPs and potential endocrine-disrupting risks in over 37.5 % of final effluent samples, with heightened effects during colder seasons. While phthalates are the predominant EEDCs (concentrations ranging from 86.39 %) for both estrogenic activity and major EEDCs (phthalates and estrogens), with the secondary and tertiary treatment segments contributing 88.59 ± 8.12 % and 11.41 ± 8.12 %, respectively. Among various secondary treatment processes, the anaerobic/anoxic/oxic-membrane bioreactor (A/A/O-MBR) excels in removing both estrogenic activity and EEDCs. In tertiary treatment, removal efficiencies increase with the inclusion of components involving physical, chemical, and biological removal principles. Furthermore, correlation and multiple liner regression analysis establish a significant (p < 0.05) positive association between solid retention time (SRT) and removal efficiencies of estrogenic activity and EEDCs within WWTPs. This study provides valuable insights from the perspective of prioritizing key pollutants, the necessity of integrating more efficient secondary and tertiary treatment processes, along with adjustments to operational parameters like SRT, to mitigate estrogenic activity in municipal WWTPs. This contribution aids in managing endocrine-disrupting risks in wastewater as part of ecological conservation efforts.

Nonylphenol and its derivatives: Environmental distribution, treatment strategy, management and future perspectives

In recent years, emerging pollutants, including nonylphenol (NP) and nonylphenol ethoxylate (NPE), have become a prominent topic. These substances are also classified as persistent organic pollutants. NP significantly affects the hormone secretion of organisms and exhibits neurotoxicity, which can affect the human hippocampus. Therefore, various countries are paying increased attention to NP regulation. NPEs are precursors of NPs and are widely used in the manufacture of various detergents and lubricants. NPEs can easily decompose into NPs, which possess strong biological and environmental toxicity. This review primarily addresses the distribution, toxicity mechanisms and performance, degradation technologies, management policies, and green alternative reagents of NPs and NPEs. Traditional treatment measures have been unable to completely remove NP from wastewater. With the progressively tightening management and regulatory policies, identifying proficient and convenient treatment methods and a sustainable substitute reagent with comparable product effectiveness is crucial.

Advances in identifying and managing emerging contaminants in aquatic ecosystems: Analytical approaches, toxicity assessment, transformation pathways, environmental fate, and remediation strategies

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management.

Isomer-specific analysis of nonylphenol and their transformation products in environment: A review

Nonylphenols (NPs) are crucial fine chemicals widely employed in producing industrial and consumer surfactants that ultimately enter the environment through various pathways, leading to environmental pollution. NPs are suspected endocrine-disrupting chemicals that may accumulate in the body over time, resulting in unusual reproductive function. Due to limitations in analytical methods, NPs have typically been quantified as a whole in some studies. However, NPs are a mixture of multibranched structures, and different NP isomers exhibit distinct environmental behaviors and toxic effects. Therefore, it is critical to analyze environmental and human biological samples at the isomer-specific level to elucidate the contamination characteristics, human exposure load, and toxic effects of NPs. Accurately analyzing NP samples with various isomers, metabolites, and transformation products presents a significant challenge. This review summarizes recent advances in analytical research on NPs in technical products, environmental, and human biological samples, particularly emphasizing the synthesis and separation of standards and the transformation of NP homolog isomers in samples. Finally, the review highlights the research gaps and future research directions in this domain.

A critical review on quantitative evaluation of aqueous toxicity in water quality assessment

Conventional chemical techniques have inherent limitations in detecting unknown chemical substances in water. As a result, effect-based methods have emerged as a viable alternative to overcome these limitations. These methods provide more accurate and intuitive evaluations of the toxic effects of water. While numerous studies have been conducted, only a few have been applied to national water quality monitoring. Therefore, it is crucial to develop toxicity evaluation methods and establish thresholds based on quantifying toxicity. This article provides an overview of the development and application of bioanalytical tools, including in vitro and in vivo bioassays. The available methods for quantifying toxicity are then summarized. These methods include aquatic life criteria for assessing the toxicity of a single compound, comprehensive wastewater toxicity testing for all contaminants in a water sample (toxicity units, whole effluent toxicity, the potential ecotoxic effects probe, the potential toxicology method, and the lowest ineffective dilution), methods based on mechanisms and relative toxicity ratios for substances with the same mode of action (the toxicity equivalency factors, toxic equivalents, bioanalytical equivalents), and effect-based trigger values for micropollutants. The article also highlights the advantages and disadvantages of each method. Finally, it proposes potential areas for applying toxicity quantification methods and offers insights into future research directions. This review emphasizes the significance of enhancing the evaluation methods for assessing aqueous toxicity in water quality assessment.

Evaluating dye recovery and reusability potential from dyebath effluent using forward osmosis membranes for minimum liquid discharge

This study focuses on the evaluation of dye recovery and reuse potential from denim and polyester effluents using forward osmosis (FO). A cationic surfactant, tetraethylammonium bromide (TEAB), was used as the draw solution (DS). After optimizing the DS and feed solution (FS) concentrations and temperatures in batch experiments, a DS concentration of 0.75 M was selected at a 60 °C temperature for the semi-continuous mode. It generated a high flux of 18 L/m2/h and a low reverse solute flux (RSF) of 0.4 g/m2/h with 100% dye rejection. Dye reconcentration of 82-98% was achieved in the dyebath effluents. The unique property of surfactants to combine hundreds of monomers into micelle resulted in negligible RSF. Reversible fouling was observed on the membrane active layer, and NaOH and citric acid cleaning achieved about 95% of flux recovery. The functional groups on the membrane's active layer remained undisturbed due to foulant interactions showing its chemical stability against reactive dyes. Recovered dye characterization using 1D proton nuclear magnetic resonance (1HNMR) analysis depicted a 100% structural resemblance to the original dye. Hence, it can be reused for dyeing the next batch. Diluted TEAB solution can be used as fabric detergent and softener within the same textile industry in the finishing process. A minimum liquid and persistent pollutant (dyes) discharge is achieved by adopting the methodology proposed in this work with a strong potential of translating it to an industrial scale.

Identification of key degraders for controlling toxicity risks of disguised toxic pollutants with division of labor mechanisms in activated sludge microbiomes: Using nonylphenol ethoxylate as an example

Efficient management of disguised toxic pollutants (DTPs), which can undergo microbial degradation and convert into more toxic substances, necessitates the collaboration of diverse microbial populations in wastewater treatment plants. However, the identification of key bacterial degraders capable of controlling the toxicity risks of DTPs through division of labor mechanisms in activated sludge microbiomes has received limited attention. In this study, we investigated the key degraders capable of controlling the risk of estrogenicity associated with nonylphenol ethoxylate (NPEO), a representative DTP, in textile activated sludge microbiomes. The results of our batch experiments revealed that the transformation of NPEO into NP and subsequent NP degradation were the rate-limiting processes for controlling the risk of estrogenicity, resulting in an inverted V-shaped curve of estrogenicity in water samples during the biodegradation of NPEO by textile activated sludge. By utilizing enrichment sludge microbiomes treated with NPEO or NP as the sole carbon and energy source, a total of 15 bacterial degraders, including Sphingbium, Pseudomonas, Dokdonella, Comamonas, and Hyphomicrobium, were identified as capable of participating in these processes, Among them, Sphingobium and Pseudomonas were the two key degraders that could cooperatively interact in the degradation of NPEO with division of labor mechanisms. Co-culturing Sphingobium and Pseudomonas isolates exhibited a synergistic effect in degrading NPEO and reducing estrogenicity. Our study underscores the potential of the identified functional bacteria for controlling estrogenicity associated with NPEO and provides a methodological framework for identifying key cooperators engaged in labor division, contributing to the management of risks associated with DTPs by leveraging intrinsic microbial metabolic interactions.

Environmental sustainability assessment of a polyester T-shirt - Comparison of circularity strategies

The considerable environmental burden of textiles is currently globally recognized. This burden can be mitigated by applying circular economy (CE) strategies to the commonly linear, short garment life cycles that end with incineration or landfill disposal. Even though all CE strategies strive to promote environmental sustainability, they might not be equally beneficial. Environmental data on different textile products is insufficiently available, which leads to complications when assessing and deciding on different CE strategies to be implemented. This paper studies the environmental impacts of a polyester T-shirt's linear life cycle through life cycle assessment (LCA) and evaluates the benefits attainable by adopting different CE strategies, and their order of priority, while noting uncertainty arising from poor data quality or unavailability. The LCA is complemented by assessing health and environmental risks related to the different options. Most of the linear life cycle's LCA-based impacts arise from use-phase washing. Hence, it is possible to reduce the environmental impact notably (37 %) by reducing the washing frequency. Adopting a CE strategy in which the shirt is reused by a second consumer, to double the number of uses, enables an 18 % impact reduction. Repurposing recycled materials to produce the T-shirt and recycling the T-shirt material itself emerged as the least impactful CE strategies. From the risk perspective, reusing the garment is the most efficient way to reduce environmental and health risks while washing frequency has a very limited effect. Combining different CE strategies offers the greatest potential for reducing both environmental impacts as well as risks. Data gaps and assumptions related to the use phase cause the highest uncertainty in the LCA results. To gain the maximum environmental benefits of utilizing CE strategies on polyester garments, consumer actions, design solutions, and transparent data sharing are needed.

Potential methanogenic and degradation of nonylphenol ethoxylate from domestic sewage: unravelling the essential roles of nutritional conditions and microbial community

Nonylphenol ethoxylathe (NPEO) is a non-ionic surfactant of increasing concern, used in the formulation of laundry detergents and is frequently found in aquatic environments. The purpose of this study was to evaluate the effects of yeast extract (YE) and sodium fumarate (SF) in NPEO removal from domestic sewage under anaerobic conditions via central composite rotatable design (CCRD) and response surface methodology (RSM). Experiments were designed by varying concentrations of NPEO (1.6-5.8 mg L^-1), YE (131.8-468.2 mg L^-1) and SF (97.7-602.3 mg L^-1) in batch reactors. SF and YE addition significantly influenced NPEO removal and CH₄ production. Optimal values of YE (400 mg L^-1) and SF (200 mg L^-1) result in removal efficiency of 97% for 5 mg L^-1 of NPEO, being mostly removed by biodegradation (86%). Meanwhile COD removal was 95% and methane yield was 134 ± 4 NmLCH₄ g^-¹COD_removed. The most abundant Bacteria genus identified were Macellibacteroides, Longilinea, Petrimonas and Proteiniphilum, while for Archaea, Methanosaeta and Methanoregula were the genera identified in higher relative abundances in optimized conditions.

EfectroH2O: Development and evaluation of a novel treatment technology for high-brine industrial wastewater

Textile production is one of the main sources of freshwater consumption by industries worldwide. In addition, according to the world bank, 20 % of the wastewater generated globally is caused by textile wet-processing. Textile wet-processing includes the processes in textile production where garments are dyed or given the final functions like water-repellency. Several thousand chemicals were used in this process, some of which are highly toxic. Discharging untreated or insufficiently treated wastewater in water bodies results in high pollution levels, severely impacting the environment and human health. Especially in textile-producing countries like India, environmental pollution and water consumption from textile wet-processing have severe impacts. Next to the high volume of chemicals used in textile production, the high salt concentration in textile wastewater also poses a challenge and is critical for freshwater systems. Moreover, textile wastewater is one of the most difficult to treat wastewater. Currently, used treatment technologies do not meet the requirements to treat textile wastewater. Therefore, the further development of efficient treatment technologies for textile wastewater is critically important. Hence, in the interdisciplinary project, effect-based monitoring demonstrates the efficiency of electrically-driven water treatment processes to remove salts and micropollutants from process water (EfectroH₂O), a low-energy Zero Liquid Discharge (ZLD) textile wastewater treatment technology is being developed consisting of a combination of capacitive deionization (CDI) and advanced oxidation processes (AOP). In addition to treatment technology development, methods for evaluating the efficiency of treatment technologies also need to be improved. Currently, mainly physicochemical parameters such as pH, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) are tested worldwide to check water quality. However, these methods are insufficient to make a statement about the toxic potential of such complex mixtures as textile wastewater. Therefore, also next to chemical analyses, effect-based methods (EBM) are used to verify the treated wastewater.

Recovering and reuse of textile dyes from dyebath effluent using surfactant driven forward osmosis to achieve zero hazardous chemical discharge

This experimental study explores the feasibility of the reuse of dyes recovered from denim and polyester dyebath effluents using forward osmosis (FO) system to achieve zero hazardous material discharge. In batch experiments, the sodium dodecyl sulfate (SDS) at 0.5 M concentration generated an average flux of 3.5 L/m²/h (LMH) and reverse salt flux (RSF) of only 0.012 g/m²/h (GMH), while maintaining 100% dye rejection. This flux stability comes from the property of surfactants to form micelles and exert a stable osmotic pressure (π) above their critical micelle concentration (CMC). The low RSF is due to the greater micelle size. A colored fouling layer was formed on the membrane active layer (AL), which was easily removed using sodium hydroxide (NaOH) and citric acid. According to Fourier transform infrared spectra and atomic forces microscopy images of the AL, the interaction between foulants and membrane active groups did not significantly affect the physiochemical properties of the membrane. In the semi-continuous experiment, a very stable average flux of 7.3 LMH and RSF of 0.03 GMH was obtained using 0.75 M SDS as draw solution. The stacked 1D proton nuclear magnetic resonance analysis (¹HNMR) spectra of both original and recovered disperse dyes showed 100% similarity, which validates the concept that the recovered dyes maintained their integrity during reconcentration and can be reused in the next batch dyeing process. Importantly, the diluted SDS concentration can be directly reused within the same textile industry in scouring and finishing processes. The processes of dye recovery and reuse developed in this study do not produce any waste or hazardous by-products and are suitable for scale-up and onsite industrial applications.

Molecular Characterization of Estrogen Receptor Agonists during Sewage Treatment Processes Using Effect-Directed Analysis Combined with High-Resolution Full-Scan Screening

Endocrine-disrupting potential was evaluated during the sewage treatment process using in vitro bioassays. Aryl hydrocarbon receptor (AhR)-, androgen receptor (AR)-, glucocorticoid receptor (GR)-, and estrogen receptor (ER)-mediated activities were assessed over five steps of the treatment process. Bioassays of organic extracts showed that AhR, AR, and GR potencies tended to decrease through the sewage treatment process, whereas ER potencies did not significantly decrease. Bioassays on reverse-phase high-performance liquid chromatography fractions showed that F5 (log K_OW 2.5-3.0) had great ER potencies. Full-scan screening of these fractions detected two novel ER agonists, arenobufagin and loratadine, which are used pharmaceuticals. These compounds accounted for 3.3-25% of the total ER potencies and 4% of the ER potencies in the final effluent. The well-known ER agonists, estrone and 17β-estradiol, accounted for 60 and 17% of the ER potencies in F5 of the influent and primary treatment, respectively. Fourier transform ion cyclotron resonance mass spectrometry analysis showed that various molecules were generated during the treatment process, especially CHO and CHOS (C: carbon, H: hydrogen, O: oxygen, and S: sulfur). This study documented that widely used pharmaceuticals are introduced into the aquatic environments without being removed during the sewage treatment process.

Treatment of synthetic dye containing textile raw wastewater effluent using UV/Chlorine/Br photolysis process followed by activated carbon adsorption

This study investigated the efficiency and feasibility of ultraviolet (UV)-assisted photolysis of synthetic dye containing textile raw wastewater effluent. For a said purpose, in-house developed UV/Chlorine/Br process was followed in the presence of activated carbon (AC) which additionally facilitate the dye adsorption. In UV/Chlorine process Cl^•, Cl₂^•-, and HO^• are generated in the solution and destroyed compounds that cannot be oxidized by the conventional oxidant. In this process, free bromine is formed and photolyzed by UV radiation and generate Br^• and Br₂^•- that can enhance the rate of pollutant degradation. In the present study, the dye removal efficiency was contributed by dark bromide (7.18%), UV irradiation (26.8%), dark chlorination (78.67%), and UV/Chlorine/Br (87.01%), respectively. With increasing pH from 3.0 to 8.30, the dye removal efficiency was enhanced but decreased by further increasing pH values. In addition, magnetized activated carbon from pomegranate husk using dual-stage chemical activation was used for post-adsorption of the residual dye and its degradation byproducts. The adsorption of the dye residues by AC followed the second-order kinetics with the rate constant of 1.7 × 10^-3. The phytotoxicity of the treated textile wastewater by UV irradiation, dark chlorination, and UV/Chlorine/Br was assessed by seed germination of Lepidium sativum seeds. The highest inhibition effect on seed germination was related to treated wastewater by UV irradiation (more than 90% inhibition) that alleviated to less than 10% when this effluent diluted to 5% v/v. The highest germination was observed when the seeds were irrigated by the effluent of the UV/Chlorine/Br process. The significant reduction in the toxicity of the treated wastewater revealed that the UV/Chlorine/Br process has a considerable potential to effectively detoxify textile wastewater. Graphical abstract.

Tiered ecological risk assessment of nonylphenol and tetrabromobisphenol A in the surface waters of China based on the augmented species sensitivity distribution models

The ecological risks of nonylphenol (NP) and tetrabromobisphenol A (TBBPA) have received continued attention owing to their large consumption, frequently detection, adverse effects on the reproductive fitness, and lack of risk assessment technical systems. The geometric mean of the median concentrations of NP in the 22 surface waters was 0.278 μg/L, and TBBPA in the seven surface waters was 0.014 μg/L in China. The species sensitivity distribution (SSD) models were augmented by extrapolated reproductive toxicity data of native species to reduce uncertainty. The SSD models and the hazardous concentrations for 5% of species exhibited good robustness and reliability using the bootstrap method and minimum sample size determination. The acute and reproductive predicted no-effect concentrations (PNECs) were derived as 9.88 and 0.187 μg/L for NP, and 56.6 and 0.0878 μg/L for TBBPA, respectively. The risk quotients indicated that 11 of 22 locations for NP, and 3 of 7 locations for TBBPA were at high ecological risk levels based on the reproductive PNECs. Furthermore, the higher tier ecological risk assessment (ERA) based on potential affected fraction and joint probability curves indicated that the ecological risks in the four of above locations needed further concern. The ERA based on both the acute and reproductive toxicity is essential for assessing the ecological risks of NP and TBBPA, otherwise using acute PNECs only may result in an underestimation of ecological risk. The developed tiered ERA method and its framework can provide accurate, detailed, quantitative, locally applicable, and economically technical support for ERA of typical endocrine-disrupting chemicals in China.

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.

Degradation of the endocrine-disrupting 4-nonylphenol by ferrate(VI): biodegradability and toxicity evaluation

4-Nonylphenol (4-NP) is an endocrine-disrupting and persistent chemical and is partially degraded in conventional wastewater treatment processes. Ferrate(VI) can be used as an environment-friendly oxidizing agent to mediate 4-NP degradation. Thus, this paper evaluates the biodegradability of 4-NP and its degradation products after the addition of ferrate(VI). The biodegradability was examined using NP labeled with ¹⁴C as a tracer and activated sludge microorganisms as an inoculum. The addition of ferrate(VI) to the 4-NP solution spiked with the tracer resulted in no remarkable decrease in the concentration of ¹⁴C, indicating incomplete mineralization of 4-NP and formation of degradation products. The degradation products from 4-NP with Fe(VI) were estimated based on mass spectra, which detected a unique peak at m/z 223 at low intensity. Four hydrogen atoms might have been added to 4-NP by degradation with Fe(VI). In addition, the effect of ferrate(VI) concentration on the estrogenic activity of 4-NP in an aqueous solution was investigated using a yeast bioassay. The results show that estrogenic activity was significantly decreased at a mass ratio of Fe(VI) to 4-NP greater than or equal to 2.5.

Co-metabolism of nonylphenol ethoxylate in sequencing batch reactor under aerobic conditions

The study evaluated the co-metabolism of nonylphenol polyethoxylate (NPEO) within a main substrate stream subjected to biodegradation in an activated sludge system. Peptone mixture simulating sewage was selected as the synthetic substrate. As a novel approach, the NPEO concentration was magnified to match the COD level of the peptone mixture, so that co-metabolism could be evaluated by respirometry and modeling. A sequencing batch reactor (SBR) set-up at high sludge age to also allow nitrification was operated for this purpose. A long acclimation phase was necessary to start NPEO biodegradation, which was completed with 15% residual by-products. Modeling of respirometric data could identify COD fractions of NPEO with corresponding process kinetics for the first time, where the biodegradation of by-products could be interpreted numerically as a hydrolysis mechanism. Nonylphenol diethoxylate (NP2EO) was observed as the major by-product affecting the biodegradation of NPEO, because NPEO and NP2EO accounted for 60 to 70% of the total soluble COD in the solution during the course of biological reactions. The co-metabolism characteristics basically defined NPEO as a substrate, with no appreciable inhibitory action on the microbial culture both in terms of heterotrophic and autotrophic activities.

Occurrence, potential ecological risks, and degradation of endocrine disrupter, nonylphenol, from the aqueous environment

Nonylphenol (NP) is considered a potential endocrine-disrupting chemical affecting humans and the environment. Due to widespread occurrence in the aquatic environment and neuro-, immuno, reproductive, and estrogenic effects, nonylphenol calls for considerable attention from the scientific community, researchers, government officials, and the public. It can persist in the environment, especially soil, for a long duration because of its high hydrophobic nature. Nonylphenol is incorporated into the water matrices via agricultural run-off, wastewater effluents, agricultural sources, and groundwater leakage from the soil. In this regard, assessment of the source, fate, toxic effect, and removal of nonylphenol seems a high-priority concern. Remediation of nonylphenol is possible through physicochemical and microbial methods. Microbial methods are widely used due to ecofriendly in nature. The microbial strains of the genera, Sphingomonas, Sphingobium, Pseudomonas, Pseudoxanthomonas, Thauera, Novosphingonium, Bacillus, Stenotrophomonas, Clostridium, Arthrobacter, Acidovorax, Maricurvus, Rhizobium, Corynebacterium, Rhodococcus, Burkholderia, Acinetobacter, Aspergillus, Pleurotus, Trametes, Clavariopsis, Candida, Phanerochaete, Bjerkandera, Mucor, Fusarium and Metarhizium have been reported for their potential role in the degradation of NP via its metabolic pathway. This study outlines the recent information on the occurrence, origin, and potential ecological and human-related risks of nonylphenol. The current development in the removal of nonylphenol from the environment using different methods is discussed. Despite the significant importance of nonylphenol and its effects on the environment, the number of studies in this area is limited. This review gives an in-depth understanding of NP occurrence, fate, toxicity, and remediation from the environments.

Inflammatory cytokines as key players of apoptosis induced by environmental estrogens in the ovary

Natural and synthetic environmental estrogens (EEs), interfering with the physiological functions of the body's estrogens, are widespread and are rising much concern for their possible deleterious effects on human and animal health, in particular on reproduction. In fact, increasing evidence indicate that EEs can be responsible for a variety of disfunctions of the reproductive system especially in females such as premature ovarian insufficiency (POI). Because of their great structural diversity, the modes of action of EEs are controversial. One important way through which EEs exert their effects on reproduction is the induction of apoptosis in the ovary. In general, EEs can exert pro-and anti-apoptotic effects by agonizing or antagonizing numerous estrogen-dependent signaling pathways. In the present work, results concerning apoptotic pathways and diseases induced by representative EEs (such as zearalenone, bisphenol A and di-2-ethylhexyl phthalate), in ovaries throughout development are presented into an integrated network. By reviewing and elaborating these studies, we propose inflammatory factors, centered on the production of tumor necrosis factor (TNF), as a major cause of the induction of apoptosis by EEs in the mammalian ovary. As a consequence, potential strategies to prevent such EE effect are suggested.