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1.
A pan-European monitoring campaign of the wastewater treatment plant (WWTP) effluents was conducted to obtain a concise picture on a broad range of pollutants including estrogenic compounds. Snapshot samples from 75 WWTP effluents were collected and analysed for concentrations of 150 polar organic and 20 inorganic compounds as well as estrogenicity using the MVLN reporter gene assay. The effect-based assessment determined estrogenicity in 27 of 75 samples tested with the concentrations ranging from 0.53 to 17.9 ng/L of 17-beta-estradiol equivalents (EEQ). Approximately one third of municipal WWTP effluents contained EEQ greater than 0.5 ng/L EEQ, which confirmed the importance of cities as the major contamination source. Beside municipal WWTPs, some treated industrial wastewaters also exhibited detectable EEQ, indicating the importance to investigate phytoestrogens released from plant processing factories. No steroid estrogens were detected in any of the samples by instrumental methods above their limits of quantification of 10 ng/L, and none of the other analysed classes of chemicals showed correlation with detected EEQs. The study demonstrates the need of effect-based monitoring to assess certain classes of contaminants such as estrogens, which are known to occur at low concentrations being of serious toxicological concern for aquatic biota. 相似文献
2.
The textile industry consumes a large volume of organic dyes and water. These organic dyes, which remained in the effluents, are usually persistent and difficult to degrade by conventional wastewater treatment techniques. If the wastewater is not treated properly and is discharged into water system, it will cause environmental pollution and risk to living organisms. To mitigate these impacts, the photo-driven catalysis process using semiconductor materials emerges as a promising approach. The semiconductor photocatalysts are able to remove the organic effluent through their mineralization and decolorization abilities. Besides the commonly used titanium dioxide (TiO2), manganese dioxide (MnO2) is a potential photocatalyst for wastewater treatment. MnO2 has a narrow bandgap energy of 1~2 eV. Thus, it possesses high possibility to be driven by visible light and infrared light for dye degradation. This paper reviews the MnO2-based photocatalysts in various aspects, including its fundamental and photocatalytic mechanisms, recent progress in the synthesis of MnO2 nanostructures in particle forms and on supporting systems, and regeneration of photocatalysts for repeated use. In addition, the effect of various factors that could affect the photocatalytic performance of MnO2 nanostructures are discussed, followed by the future prospects of the development of this semiconductor photocatalysts towards commercialization. 相似文献
3.
Photocatalytic process has shown recently a great potential as an environmental friendly and clean remediation technology for organic pollutants in wastewater. This work described the synthesis of silver-based bimetallic nanoparticles using colloid chemistry and the subsequent immobilization onto titania to form composite photocatalytic materials (titania-supported Ag–Pt nanoparticles). The photocatalysts were characterized by X-ray diffraction, electron microscopy, and nitrogen physisorption. The catalytic activity of the photocatalysts was evaluated by photocatalytic degradation of phenol and 2-chlorophenol (2-CP) in synthetic wastewater solutions. The photocatalytic processes were conducted in a batch photoreactor containing appropriate solutions of phenol and 2-CP with UV irradiation of 450 W. UV-visible spectrophotometer was used for analyzing the concentration of phenol and 2-CP in solutions. Parameters affecting the photocatalytic process such as the solution pH, phenol and 2-CP concentrations, and catalyst concentration were investigated. The results obtained revealed that TiO 2-supported Ag/Pt nanoparticles showed a higher activity for UV-photocatalytic degradation of both phenol and 2-CP pollutants in the solution (as compared to the plain rutile TiO 2). The photodegradation processes were optimized by the 0.5-g/L catalyst with a pollutant concentration of 50 mg/L for all the samples. Complete degradation for both phenol and 2-CP was achieved after 120 min. 相似文献
4.
Photocatalytic degradation of bisphenol A (BPA) in waters and wastewaters in the presence of titanium dioxide (TiO 2) was performed under different conditions. Suspensions of the TiO 2 were used to compare the degradation efficiency of BPA (20 mg L ?1) in batch and compound parabolic collector (CPC) reactors. A TiO 2 catalyst supported on glass spheres was prepared (sol–gel method) and used in a CPC solar pilot plant for the photodegradation of BPA (100 μg L ?1). The influence of OH·, O 2 ·?, and h + on the BPA degradation were evaluated. The radicals OH· and O 2 ·? were proved to be the main species involved on BPA photodegradation. Total organic carbon (TOC) and carboxylic acids were determined to evaluate the BPA mineralization during the photodegradation process. Some toxicological effects of BPA and its photoproducts on Eisenia andrei earthworms were evaluated. The results show that the optimal concentration of suspended TiO 2 to degrade BPA in batch or CPC reactors was 0.1 g L ?1. According to biological tests, the BPA LC 50 in 24 h for E. andrei was of 1.7?×?10 ?2 mg cm ?2. The photocatalytic degradation of BPA mediated by TiO 2 supported on glass spheres suffered strong influence of the water matrix. On real municipal wastewater treatment plant (MWWTP) secondary effluent, 30 % of BPA remains in solution; nevertheless, the method has the enormous advantage since it eliminates the need of catalyst removal step, reducing the cost of treatment. 相似文献
5.
Lanthanum-modified TiO 2 photocatalysts (0.2–1.5 wt% La) were investigated in the methanol decomposition in an aqueous solution. The photocatalysts were prepared by the common sol-gel method followed by calcination. The structural (X-ray diffraction, Raman, X-ray photoelectron spectroscopy), textural (N 2 physisorption), and optical properties (diffuse reflectance spectroscopy, photoelectrochemical measurements) of all synthetized nanomaterials were correlated with photocatalytic activity. Both pure TiO 2 and La-doped TiO 2 photocatalysts proved higher yields of hydrogen in comparison to photolysis. The photocatalyst with optimal amount of lanthanum (0.2 wt% La) showed almost two times higher amount of hydrogen produced at the same time as in the presence of pure TiO 2. The photocatalytic activity increased with both increasing photocurrent response and decreasing amount of lattice and surface O species. It has been shown that both direct and indirect mechanisms of methanol photocatalytic oxidation participate in the production of hydrogen. Both direct and indirect mechanisms take part in the formation of hydrogen. 相似文献
6.
We investigated the adsorption and decomposition of sulfamethazine (SMT), which is used as a synthetic antibacterial agent and discharged into environmental water, using high-silica Y-type zeolite (HSZ-385), titanium dioxide (TiO 2), and TiO 2–zeolite composites. By using ultrapure water and secondary effluent as solvents, we prepared SMT solutions (10 μg/L and 10 mg/L) and used them for adsorption and photocatalytic decomposition experiments. When HSZ-385 was used as an adsorbent, rapid adsorption of SMT in the secondary effluent was confirmed, and the adsorption reached equilibrium within 10 min. The photocatalytic decomposition rate using TiO 2 in the secondary effluent was lower than that in ultrapure water, and we clarified the inhibitory effect of ions and organic matter contained in the secondary effluent on the reaction. We synthesized TiO 2–zeolite composites and applied them to the removal of SMT. During the treatment of 10 μg/L SMT in the secondary effluent using the composites, 76 % and more than 99 % of the SMT were decomposed within 2 and 4 h by photocatalysis. The SMT was selectively adsorbed onto high-silica Y-type zeolite in the composites. Resultantly, the inhibitory effect of the coexisting materials was reduced, and the composites could remove SMT more effectively compared with TiO 2 alone in the secondary effluent. 相似文献
7.
The photocatalytic reduction of CO 2 with H 2O was investigated using Cu/TiO 2 photocatalysts in aqueous solution. For this purpose, Cu/TiO 2 photocatalysts (with 0.2, 0.9, 2, 4, and 6 wt.% of Cu) have been synthesized via sol-gel method. The photocatalysts were extensively characterized by means of inductively coupled plasma optical emission spectrometry (ICP-OES), N 2 physisorption (BET), XRD, UV-vis DRS, FT-IR, Raman spectroscopy, TEM-EDX, and photoelectrochemical measurements. The as-prepared photocatalysts contain anatase as a major crystalline phase with a crystallite size around 13 nm. By increasing the amount of Cu, specific surface area and band gap energy decreased in addition to the formation of large agglomeration of CuO. Results revealed that the photocatalytic reduction of CO 2 decreased in the presence of Cu/TiO 2 in comparison to pure TiO 2, which might be associated to the formation of CuO phase acting as a recombination center of generated electron-hole pair. Decreasing of photoactivity can also be connected with a very low position of conduction band of photocatalysts with high Cu content, which makes H 2 production necessary for CO 2 reduction more difficult. 相似文献
8.
This work aimed to optimize high-performance photocatalysts based on graphene oxide/titanium dioxide (GO/TiO 2) nanocomposites for the effective degradation of aqueous pollutants. The catalytic activity was tested against the degradation of dichloroacetic acid (DCA), a by-product of disinfection processes that is present in many industrial wastewaters and effluents. GO/TiO 2 photocatalysts were prepared using three different methods, hydrothermal, solvothermal, and mechanical, and varying the GO/TiO 2 ratio in the range of 1 to 10%. Several techniques were applied to characterize the catalysts, and better coupling of GO and TiO 2 was observed in the thermally synthesized composites. Although the results obtained for DCA degradation showed a coupled influence of the composite preparation method and its composition, promising results were obtained with the photocatalysts compared to the limited activity of conventional TiO 2. In the best case, corresponding to the composite synthesized via hydrothermal method with 5% of GO/TiO 2 weight ratio, an enhancement of 2.5 times of the photocatalytic degradation yield of DCA was obtained compared to bare TiO 2, thus opening more efficient ways to promote the application of photocatalytic remediation technologies. 相似文献
9.
Conventional wastewater treatment plants (WWTPs) are not able to remove completely some emerging contaminants, such as residual pharmaceutical compounds (PCs) with potential ecotoxicity to water bodies. An advanced bio-oxidation process (ABOP) using white-rot fungi (WRF) has been proposed as alternative biological treatment for degradation of non-biodegradable compounds. A synthetic and real wastewater spiked with 12 PCs at 50 μg L ?1 was treated by means of ABOP based on WRF in a rotating biological contactor (RBC) at 1 day of hydraulic retention time (HRT). The ABOP achieved a remarkable biological performance in terms of TOC removal and reduction of N-NH 4 + and P-PO 4 3? nutrients. Likewise, 5 of the 12 PCs were eliminated with removal efficiencies ranging from 80 to 95%, whereas 6 of 12 PCs were eliminated with removal values ranging from 50 to 70%. The anaerobic digestion of the fungal sludge generated upon the treatment was also evaluated, obtaining a methane yield of 250 mL CH 4 g VS ?1. These results evidenced that the proposed ABOP is a promising alternative for the sustainable wastewater treatment of urban effluents, combining advanced oxidation with biological operation for the removal of emerging PCs and energy recovery. 相似文献
10.
This study reports the synthesis and characterization of composite nitrogen and fluorine co-doped titanium dioxide (NF-TiO 2) for the removal of contaminants of concern in wastewater under visible and solar light. Monodisperse anatase TiO 2 nanoparticles of different sizes and Evonik P25 were assembled to immobilized NF-TiO 2 by direct incorporation into the sol–gel or by the layer-by-layer technique. The composite films were characterized with X-ray diffraction, high-resolution transmission electron microscopy, environmental scanning electron microscopy, and porosimetry analysis. The photocatalytic degradation of atrazine, carbamazepine, and caffeine was evaluated in a synthetic water solution and in an effluent from a hybrid biological concentrator reactor (BCR). Minor aggregation and improved distribution of monodisperse titania particles was obtained with NF-TiO 2-monodisperse (10 and 50 nm) from the layer-by-layer technique than with NF-TiO 2?+?monodisperse TiO 2 (300 nm) directly incorporated into the sol. The photocatalysts synthesized with the layer-by-layer method achieved significantly higher degradation rates in contrast with NF-TiO 2-monodisperse titania (300 nm) and slightly faster values when compared with NF-TiO 2-P25. Using NF-TiO 2 layer-by-layer with monodisperse TiO 2 (50 nm) under solar light irradiation, the respective degradation rates in synthetic water and BCR effluent were 14.6 and 9.5?×?10 ?3?min ?1 for caffeine, 12.5 and 9.0?×?10 ?3?min ?1 for carbamazepine, and 10.9 and 5.8?×?10 ?3?min ?1 for atrazine. These results suggest that the layer-by-layer technique is a promising method for the synthesis of composite TiO 2-based films compared to the direct addition of nanoparticles into the sol. 相似文献
11.
Annihilation of electrons–holes recombination process is the main remedy to enhance the photocatalytic activity of the semiconductors photocatalysts. Doping of this class of photocatalysts by foreign nanoparticles is usually utilized to create high Schottky barrier that facilitates electron capture. In the literature, because nonpolar nanoparticles (usually pristine metals, e.g., Ag, Pt, Au, etc.) were utilized in the doping process, the corresponding improvement was relatively low. In this study, CdSO 4-doped TiO 2 nanoparticles are introduced as a powerful and reusable photocatalyst for the photocatalytic degradation of methomyl pesticide in concentrated aqueous solutions. The utilized CdSO 4 nanoparticles form polar grains in the TiO 2 matrix due to the electrons leaving characteristic of the sulfate anion. The introduced nanoparticles could successfully eliminate the harmful pesticide under the sunlight radiation within a very short time (less than 1 h), with a removal capacity reaching 1,000 mg pesticide per gram of the introduced photocatalyst. Moreover, increase in the initial concentration of the methomyl did not affect the photocatalytic performance; typically 300, 500, 1,000, and 2,000 mg/l solutions were completely treated within 30, 30, 40, and 60 min, respectively, using 100 mg catalyst. Interestingly, the photocatalytic efficiency was not affected upon multiple use of the photocatalyst. Moreover, negative activation energy was obtained which reveals super activity of the introduced photocatalyst. The distinct photocatalytic activity indicates the complete annihilation of the electrons–holes recombination process and abundant existence of electrons on the catalyst surfaces due to strong electrons capturing the operation of the utilized polar CdSO 4 nanoparticles. The introduced photocatalyst has been prepared using the sol–gel technique. Overall, the simplicity of the synthesizing procedure and the obtained featured photocatalytic activity strongly recommend the introduced nanoparticles to treat the methomyl-containing polluted water. 相似文献
12.
The present work mainly deals with photocatalytic degradation of a herbicide, erioglaucine, in water in the presence of TiO 2 nanoparticles (Degussa P-25) under ultraviolet (UV) light illumination (30 W). The degradation rate of erioglaucine was not so high when the photolysis was carried out in the absence of TiO 2 and it was negligible in the absence of UV light. We have studied the influence of the basic photocatalytic parameters such as pH of the solution, amount of TiO 2, irradiation time and initial concentration of erioglaucine on the photodegradation efficiency of erioglaucine. A kinetic model is applied for the photocatalytic oxidation by the UV/TiO 2 system. Experimental results indicated that the photocatalytic degradation process could be explained in terms of the Langmuir–Hinshelwood kinetic model. The values of the adsorption equilibrium constant, K, and the second order kinetic rate constant, k, were 0.116 ppm ? 1 and 0.984 ppm min ? 1, respectively. In this work, we also compared the reactivity between the commercial TiO 2 Degussa P-25 and a rutile TiO 2. The photocatalytic activities of both photocatalysts were tested using the herbicide solution. We have noticed that photodegradation efficiency was different between both of them. The higher photoactivity of Degussa P-25 compared to that of rutile TiO 2 for the photodegradation of erioglaucine may be due to higher hydroxyl content, higher surface area, nano-size and crystallinity of the Degussa P-25. Our results also showed that the UV/TiO 2 process with Degussa P-25 as photocatalyst was appropriate as the effective treatment method for removal of erioglaucine from a real wastewater. The electrical energy consumption per order of magnitude for photocatalytic degradation of erioglaucine was lower with Degussa P-25 than in the presence of rutile TiO 2. 相似文献
13.
Advanced oxidation processes using semiconducting photocatalysts for the degradation of organic pollutants are a promising approach for the remediation of pesticide-contaminated wastewater. High photodegradation efficiency and stability of the photocatalyst are of key importance for practical application of the semiconductor. In this study, mesoporous TiO 2/ZrO 2 nanopowders were synthesized via two techniques; evaporation-induced self-assembly (EISA) and sol-gel using triblock copolymers Pluronic P123 and F127. The photodegradation activities of the composites were determined by employing the herbicide chloridazon as a model compound. Due to well-developed mesoporosity, the TiO 2/ZrO 2 nanocomposite synthesized by EISA displays high surface area and small crystallite sizes leading to higher photocatalytic activity than pristine TiO 2 prepared under similar condition and commercial Degussa P25 nanopowder. The optimum amount of zirconium required for the highest activities was identified and found to be 0.14 and 0.05 mol% for the EISA and sol-gel-prepared samples, respectively. Systematic studies of the post-thermal treatment step for both samples show that Zr inhibits an anatase-to-rutile phase transition only up to 600 °C, at higher temperature phase separation occurs. Samples synthesized by EISA method showed enhanced degradation activity than sol-gel-synthesized samples. 相似文献
14.
This study investigated the photocatalytic degradation of acetaminophen (ACT) in synthetic titanium dioxide (TiO 2) solution under a visible light ( λ >440 nm). The TiO 2 photocatalyst used in this study was synthesized via sol–gel method and doped with potassium aluminum sulfate (KAl(SO 4) 2) and sodium aluminate (NaAlO 2). The influence of some parameters on the degradation of acetaminophen was examined, such as initial pH, photocatalyst dosage, and initial ACT concentration. The optimal operational conditions were also determined. Results showed that synthetic TiO 2 catalysts presented mainly as anatase phase and no rutile phase was observed. The results of photocatalytic degradation showed that LED alone degraded negligible amount of ACT but with the presence of TiO 2/KAl(SO 4) 2, 95 % removal of 0.10-mM acetaminophen in 540-min irradiation time was achieved. The synthetic TiO 2/KAl(SO 4) 2 presented better photocatalytic degradation of acetaminophen than commercially available Degussa P-25. The weak crystallinity of synthesized TiO 2/NaAlO 2 photocatalyst showed low photocatalytic degradation than TiO 2/KAl(SO 4) 2. The optimal operational conditions were obtained in pH 6.9 with a dose of 1.0 g/L TiO 2/KAl(SO 4) 2 at 30 °C. Kinetic study illustrated that photocatalytic degradation of acetaminophen fits well in the pseudo-first order model. Competitive reactions from intermediates affected the degradation rate of ACT, and were more obvious as the initial ACT concentration increased. 相似文献
15.
The removal of 12 pharmaceuticals and personal care products (PPCPs) in two full-scale wastewater treatment plants (WWTPs) and a tertiary treatment system was studied. The ecological risks of effluents from both secondary and tertiary treatment systems as well as excess sludge were evaluated. Primary treatment and ultraviolet light disinfection showed limited ability to remove most selected PPCPs. The combination of an anaerobic process and triple-oxidation ditches can eliminate DEET better than the anaerobic/anoxic/oxic process. Adsorption to sludge played a key role in the removal of triclocarban. Multistage constructed wetlands as a tertiary treatment efficiently removed caffeine and ibuprofen from wastewater and could decrease the risk of partial selected PPCPs. Selected PPCPs residues in excess sludge generally produced higher risks to the ecological environment than effluents from WWTPs. 相似文献
16.
Titanium dioxide (TiO 2) has been considered a useful material for the treatment of wastewater due to its non-toxic character, chemical stability and excellent electrical and optical properties which contribute in its wide range of applications, particularly in environmental remediation technology. However, the wide band gap of TiO 2 photocatalyst (anatase phase, 3.20 eV) limits its photocatalytic activity to the ultraviolet region of light. Besides that, the electron-hole pair recombination has been found to reduce the efficiency of the photocatalyst. To overcome these problems, tailoring of TiO 2 surface with rare earth metals to improve its surface, optical and photocatalytic properties has been investigated by many researchers. The surface modifications with rare earth metals proved to enhance the efficiency of TiO 2 photocatalyts by way of reducing the band gap by shifting the working wavelength to the visible region and inhibiting the anatase-to-rutile phase transformations. This review paper summarises the attempts on modification of TiO 2 using rare earth metals describing their effect on the photocatalytic activities of the modified TiO 2 photocatalyst. 相似文献
17.
The simultaneous photocatalytic removal of nitrate from aqueous environment in presence of organic hole scavenger using TiO 2 has long been explored. However, the use of unmodified TiO 2 in such reaction resulted in non-performance or release of significant amount of undesirable reaction products in the process, a problem that triggered surface modification of TiO 2 for enhanced photocatalytic performance. Previous studies focused on decreasing rate of charge carrier recombination and absorption of light in the visible region. Yet, increasing active sites and adsorption capacity by combining TiO 2 with a high surface area adsorbent such as activated carbon (AC) remains unexploited. This study reports the potential of such modification in simultaneous removal of nitrates and oxalic acid in aqueous environment. The adsorptive behaviour of nitrate and oxalic acid on TiO 2 and TiO 2/AC composites were studied. The Langmuir adsorption coefficient for nitrate was four times greater than that of oxalic acid. However, the amount of oxalic acid adsorbed was about 10 times greater than the amount of nitrate taken up. Despite this advantage, the materials did not appear to produce more active photocatalysts for the simultaneous degradation of nitrate and oxalic acid. The photocatalytic activity of TiO 2 and its carbon-based composites was improved by combination with Cu 2O particles. Consequently, 2.5 Cu 2O/TiO 2 exhibited the maximum photocatalytic performance with 57.6 and 99.8% removal of nitrate and oxalic acid, respectively, while selectivity stood at 45.7, 12.4 and 41.9% for NH 4+, NO 2? and N 2, respectively. For the carbon based, 2.5 Cu 2O/TiO 2-20AC showed removal of 12.7% nitrate and 80.3% oxalic acid and achieved 21.6, 0 and 78.4% selectivity for NH 4+, NO 2? and N 2, respectively. Using the optimal AC loading (20 wt%) resulted in significant decrease in the selectivity for NH 4+ with no formation of NO 2?, which unveils that selectivity for N 2 and low/no selectivity for undesirable products can be manipulated by controlling the rate of consumption of oxalic acid. In contract, no nitrate reduction was observed with Cu 2O promoted TiO 2-T and its TiO 2-(T)-20AC, which may be connected to amorphous nature of TiO 2-T and perhaps served as charge carrier trapping sites that impeded activity. 相似文献
18.
Coupled Bi 2O 3/TiO 2 photocatalysts were fabricated by sol–gel and hydrothermal methods and characterized using various spectroscopy techniques. Photocatalytic reduction of Cr(VI) in aqueous solution, together with the synergistic effect of photodegradation of bisphenol A (BPA), was investigated using these coupled Bi 2O 3/TiO 2 under visible-light irradiation. Coupling of Bi 2O 3 inhibited the phase transformation from anatase to rutile and extended absorption region to visible light. Bi ions did not enter TiO 2 lattice and were more likely to bond with oxygen atoms to form Bi 2O 3 on the surface of TiO 2. Photovoltage signals in visible range revealed the effective interfacial charge transfer between Bi 2O 3 and TiO 2. Two percent Bi 2O 3/TiO 2 exhibited the highest photocatalytic activity of visible-light-induced reduction of Cr(VI). The addition of BPA effectively increased the photocatalytic reduction of Cr(VI). Simultaneously, the presence of Cr(VI) promoted the degradation of BPA, which was demonstrated by the investigation of TOC removal yield and generated intermediates. A possible mechanism of photocatalytic reduction of Cr(VI) and degradation of BPA in Bi 2O 3/TiO 2 system was proposed. The synergistic effect, observed between reduction of Cr(VI) and degradation of BPA, provides beneficial method for environmental remediation and purification of the complex wastewater. 相似文献
19.
The fate and transport of endocrine disrupting chemicals (EDCs) in ambient river waters is a major concern associated with effluents from municipal wastewater treatment plants (WWTPs). This paper presents a methodology for quantifying the spatial distribution of EDCs in a river mixing zone. The core of the technical analysis is based on a two-dimensional steady-state analytical model characterized by ambient turbulence in the receiving water. This model was first calibrated with mass transport data from field measurements for a conservative substance (electrical conductivity) and then used to predict aqueous-phase EDC concentrations throughout a WWTP mixing zone. To demonstrate the usefulness of this methodology for water quality management purposes, the modeling framework presented in this paper was used to determine a lumped in-stream attenuation rate constant ( kd = 3 d −1) for 17β-estradiol under natural conditions. This rate constant likely accounts for the combined contributions of physical sorption, photolysis, microbial and chemical degradation, and the measured value is highly consistent with previously published results from bench-scale removal experiments. 相似文献
20.
Estrogenic potencies of the effluents or water samples from wastewater treatment plants (WWTPs), industries and hospitals and some receiving rivers in Beijing city were estimated by using a human estrogen receptor recombinant yeast assay. Estrogenic activity of industrial wastewaters was found to range from 0.1 to 13.3 ng EEQ/L and decreased to the range of 0.03-1.6 ng EEQ/L after treatment. Estrogenic activity in WWTP influent ranged from 0.3 to 1.7 ng EEQ/L and decreased to the range of 0.05-0.5 ng EEQ/L after treatment. In the receiving river waters, the estrogenic effect range was 0.1-4.7 ng EEQ/L. These data suggest that treated industrial effluents and WWTP effluents of concern are not the only source of estrogenic pollution in surface waters in Beijing city. EEQ levels in Beijing river water are likely attributable to untreated municipal and industrial wastewaters discharged directly into the river. 相似文献
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