Degradation Of 17α-ethinylestradiol Research Articles

Photoinduced RhB-sensitized effect on a novel AgI/BiOCl/biochar photocatalyst to boost its photocatalytic performance for 17α-ethinyl estradiol degradation

In this study, a simple and effective strategy was developed for the synthesis of novel visible-light-active AgI/BiOCl/biochar (AgI/BiOCl/BC) photocatalysts. The addition of rhodamine B (RhB) as a sensitizer was found to considerably enhance the photocatalytic activity of AgI/BiOCl/BC toward the degradation of 17α-ethinyl estradiol (EE2). Furthermore, the incorporation of biochar (BC) into the BiOCl resulted in an increased abundance of free radicals, that could be used for degradation. Additionally, the presence of BC facilitated the separation of carriers by serving as an electron transport channel. The photocatalytic efficiency of the AgI/BiOCl/BC photocatalyst was shown to be highly effective in the degradation of EE2, the degradation efficiency of the AgI/BiOCl/BC was found to be 98.60 % after a 12-min exposure to visible light. Additionally, the photocatalytic activity increased further when RhB sensitization was performed, resulting in a remarkable elimination efficiency of 99.60 % for EE2 after only 4 min of photocatalysis. RhB could not only provide photosensitivity but also degrade along with EE2 as a pollutant, which can be used for the treatments of dyes and EE2 wastewater. The results of photocatalysis investigations indicated that AgI/BiOCl/BC could degrade various dyes, including methyl orange (MO), methylene blue (MB), and congo red (CR). Through the introduction of Ag-based materials, the obtained AgI/BiOCl/BC photocatalyst exhibited significant antibacterial potential against Staphylococcus aureus and Escherichia coli, with antibacterial rates of 99.94 % and 99.99 %, respectively. The cyclic experiment demonstarted that AgI/BiOCl/BC exhibited excellent stability and recyclability. Furthermore, the potential photocatalytic mechanism and degradation pathway were suggested through a combination of experimental findings and theoretical investigations. The obtained AgI/BiOCl/BC photocatalyst is a multifunctional photocatalyst with excellent performance in photocatalytic degradation and sterilization. This photocatalyst is expected to be applied to the treatment of complex pollutant water in the environmental field.

Application and ecotoxicological evaluation of UV-assisted peroxidation for degradation of 17α-ethinylestradiol in aqueous media

Application and ecotoxicological evaluation of UV-assisted peroxidation for degradation of 17α-ethinylestradiol in aqueous media

Preparation of BiOI Photocatalysts with Controllable Wettability and Their Enhanced Catalytic Degradation of 17α-ethinylestradiol

In this study, BiOI was successfully synthesized using a hydrothermal method and then modified using hexamethyldisiloxane (HMDS) and polydimethylsiloxane (PDMS), respectively, to achieve a controllable water contact angle (WCA) for these materials. The physical and chemical properties of the modified BiOI were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FTIR) spectroscopy and water contact angle (WCA) techniques. Compared with the unmodified BiOI, HMDS- and PDMS-modified BiOI had higher photocatalytic activities for 17[Formula: see text]-ethinylestradiol (EE2) under visible light irradiation for 28 min after reacting in dark for 30 min. When BiOI was modified using HMDS and PDMS, the WCA increased. When the WCA of HMDS- and PDMS-modified BiOI was controlled in the range of 25.3–32.7[Formula: see text] and 38.1–78.5[Formula: see text], respectively, better photocatalytic performances were achieved. When the WCA of modified BiOI was 29.7[Formula: see text] (1.00[Formula: see text]mL HMDS) and 47.8[Formula: see text] (0.20[Formula: see text]mL PDMS), the best photocatalytic performances were achieved with EE2 removal rate of 98.85% and 98.72%, respectively, however, the removal rate of the unmodified BiOI was 85.01%. The reaction rate constants of BiOI (1.00[Formula: see text]mL HMDS) and BiOI (0.20[Formula: see text]mL PDMS) were 2.33 and 2.15 times higher than the unmodified BiOI, respectively. The improved catalytic performances of modified BiOI could be attributed to the synergistic effect of the controlled wettability of BiOI and functional groups on the surface of photocatalysts.

Degradation of 17α-ethinylestradiol by Enterobacter tabaci Isolate and Kinetic Characterization

In the present study, the degradability of 17α-ethinylestradiol (EE2) by isolated bacterial strains from the activated sludge of the wastewater treatment plant of a factory manufacturing contraceptive pills was investigated. The strain with more degradation capacity of EE2 (strain S1) was identified as Enterobacter tabaci based on its morphology and analysis of the 16S rRNA sequence. The isolated strains were used in the form of pure (containing the identified bacterial strain) and mixed (containing the two isolated bacterial strains) cultures for degradation of EE2 as the sole carbon and energy source. The added substrate (0–4 mg L−1) was metabolized almost completely within 4 d at 30 °C. EE2 was used as the growth substrate by the bacterial cultures, since the biomass concentration was obviously increased. EE2 biodegradation was kinetically investigated according to the kinetic data obtained by fitted appropriate models (the Monod model and the allosteric sigmoidal model were used for the pure and the mixed bacterial cultures, respectively). The first-order kinetic rate constant ( $$ \frac{q_m}{K_s} $$ ) for EE2 utilization by the pure culture was noticeably higher than the value obtained by the mixed culture, probably due to preference of the isolated bacterial strain to estrogenic compounds as the growth substrate by producing specific enzymes. By comparing the degradation and also the growth kinetic parameters, it was concluded that the pure bacterial culture had better efficiency in degradation of EE2.

Photocatalytic Removal of 17α-Ethinyl Estradiol Using the Bi2O3/Bi2O4 Photocatalyst

A series of Bi2O3/Bi2O4 composites were prepared by calcining raw materials with different NaBiO3/KOH mass ratios. The Bi2O3/Bi2O4 photocatalysts were characterized by the various measurements and their photocatalytic performance was assessed by degradation of 17α-ethinyl estradiol (EE2). The Bi2O3/Bi2O4 photocatalysts have wider visible light absorption and lower fluorescence emission intensity than the commercial Bi2O3. So, they displayed superior performance in the degradation of EE2. After the adsorption equilibrium of EE2 was reached, the degradation efficiency of Bi2O3/Bi2O4 for EE2 can reach a maximum value of ~ 100% in 12 min under the visible-light illumination. Degradation analysis results indicated that both holes (h+) and superoxide radical (·O2−) can affect the degradation efficiency of EE2.

Synergistic effects of biogenic manganese oxide and Mn(II)-oxidizing bacterium Pseudomonas putida strain MnB1 on the degradation of 17 α-ethinylestradiol

While biogenic manganese oxide (BMO) generated via the oxidation of Mn(II) by the Mn-oxidizing bacteria (MOB) have received attention, the relative roles of biological activity by MOB themselves were not clearly investigated. In this study, the synergistic effects of BMO and MOB Pseudomonas putida strain MnB1 on the degradation of 17α-ethinylestradiol (EE2) was investigated. Experiments with BMO in the presence of P. putida MnB1 showed 15-fold higher removal than that with BMO alone, suggesting that EE2 degradation was mediated by the biological activity of MOB as well as abiotic reaction by BMO. Trapping experiments with pyrophosphate (PP) proved that Mn(III) intermediate formed during the biological process from Mn (II) to Mn (IV) contribute much to the EE2 removal. Also, sharp decreases in EE2 removal were observed when microbial activity was inactivated by heat treatment or sodium azide. From this study, the EE2 removal mechanisms by BMO in the presence P. putida MnB1 are described as follows: (1) abiotic oxidation of EE2 by BMO occurs. (2) P. putida MnB1 indirectly oxidizes EE2 by transferring electrons from the Mn (III) intermediate. (3) P. putida MnB1 continuously re-oxidizes the Mn(II) released from the oxidative degradation of EE2 by BMO, generating new Mn(III)-intermediates or BMO.

Degradation of 17α-ethinylestradiol by nano zero valent iron under different pH and dissolved oxygen levels

The catalytic properties of nanoparticles (e.g., nano zero valent iron, nZVI) have been used to effectively treat a wide range of environmental contaminants. Emerging contaminants such as endocrine disrupting chemicals (EDCs) are susceptible to degradation by nanoparticles. Despite extensive investigations, questions remain on the transformation mechanism on the nZVI surface under different environmental conditions (redox and pH). Furthermore, in terms of the large-scale requirement for nanomaterials in field applications, the effect of polymer-stabilization used by commercial vendors on the above processes is unclear. To address these factors, we investigated the degradation of a model EDC, the steroidal estrogen 17α-ethinylestradiol (EE2), by commercially sourced nZVI at pH 3, 5 and 7 under different oxygen conditions. Following the use of radical scavengers, an assessment of the EE2 transformation products shows that under nitrogen purging direct reduction of EE2 by nZVI occurred at all pHs. The radicals transforming EE2 in the absence of purging and upon air purging were similar for a given pH, but the dominant radical varied with pH. Upon air purging, EE2 was transformed by the same radical species as the non-purged system at the same respective pH, but the degradation rate was lower with more oxygen – most likely due to faster nZVI oxidation upon aeration, coupled with radical scavenging. The dominant radicals were OH at pH 3 and O2− at pH 5, and while neither radical was involved at pH 7, no conclusive inferences could be made on the actual radical involved at pH 7. Similar transformation products were observed without purging and upon air purging.

Degradation behavior of 17α-ethinylestradiol by ozonation in the synthetic secondary effluent

AbstractEndocrine disrupting chemicals (EDCs) in the secondary effluent discharged from wastewater treatment plants (WWTPs) are of great concern in the process of water reuse. Ozonation has been reported as a powerful oxidation technology to eliminate micropollutants in water treatment. Due to the complexity of the wastewater matrix, orthogonal experiments and single factor experiments were conducted to study the influence of operational parameters on the degradation of 17α-ethinylestradiol (EE2) in the synthetic secondary effluent. The results of the orthogonal experiments indicated that the initial ozone and natural organic matter (NOM) concentration significantly affected EE2 degradation efficiency, which was further validated by the single factor confirmation experiments. EE2 was shown to be effectively degraded by ozonation in the conditions of low pH (6), NOM (10 mg/L), carbonate (50 mg/L), but high suspended solid (20 mg/L) and initial ozone concentration (9 mg/L). The study firstly revealed that the lower pH resulted in higher degradation of EE2 in the synthetic secondary effluent, which differed from EDCs ozonation behavior in pure water. EE2 degradation by ozone molecule instead of hydroxyl radical was proposed to play a key role in the degradation of EDCs by ozonation in the secondary effluent. The ratio between O3 and TOC was identified as an appropriate index to assess the degradation of EE2 by ozonation in the synthetic secondary effluent.

Degradation of 17α-ethinylestradiol by ozonation — Identification of the by-products and assessment of their estrogenicity and toxicity

The presence of the synthetic estrogen 17α-ethinylestradiol (EE2) in waters at low levels is a concern due to its ability to act as an endocrine disruptor. Ozone (O 3) is commonly used in water treatment and reacts with EE2 to form by-products having characteristics that are mostly unknown. The aim of this study was to identify the by-products of E2 and EE2 ozonation and determine their estrogenicity and toxicity relative to the parent compound. Ozonation by-products were identified via LC–MS analysis. The estrogenicity was measured using the YES assay, and toxicity was determined by monitoring effects on histology of fetal rat testes and testosterone secretion by these tissues. Two EE2 by-products were identified with open phenolic ring structures (masses 302 and 344 u). The Yeast Estrogen Screening (YES) assay showed a decreased but incomplete removal of estrogenicity after ozonation of EE2. Histological analysis of fetal testes revealed that neither E2 nor EE2, with or without ozonation, had any effect on seminiferous cord formation; however, a remarkable negative effect on testosterone secretion was observed, with EE2 by-products after ozonation showing the most rapid and extensive inhibition. These results show that the removal of EE2 via reaction with O 3 resulted in the formation of by-products that are less estrogenic (as demonstrated by the YES assay), but have a greater negative impact on testosterone secretion. Thus, the disappearance of the parent compound is not a sufficient endpoint, as the by-products created may be more toxic. Care should be taken when implementing oxidation applications such as ozone during waste water treatment.

Degradation of 17α-ethinylestradiol in aqueous solution by ozonation

This study investigates the ozonation of 17α-ethinylestradiol (EE 2) in aqueous solution. The affecting factors on the degradation of EE 2 were studied and described in details, such as initial EE 2 concentration, initial pH value and ozone concentration. In addition, some parameters such as pH, electrical conductivity, mineralization efficiency and degradation products were monitored during the process. The mineralization efficiency of EE 2 could reach 53.9%. During the ozonation process the rapid decrease of pH and the sharp increase of electrical conductivity indicated the formation of acidic by-products, small fragments and ions which were confirmed by high performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC/MS) analysis. Results showed that there were intermediate products of smaller molecule with higher polarity produced during the course of EE 2 degradation. Then a possible reaction pathway for EE 2 degradation involving all intermediates detected is proposed. During the ozonation process EE 2 was first oxidized into hydroxyl-semiquinone isomers which were subsequently degraded into low molecular weight compounds such as oxalic acid, malonate, glutarate, and so on. Furthermore, these organic acids are easily oxidized by ozone into carbon dioxide (CO 2). This work shows that ozonation process is promising for the removal of EE 2. The results can provide some useful information for the potential treatment of EE 2 by ozonation in aqueous solution.