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1-2-7-三氨基-8-羟基-3-6-萘二磺酸(TAHNDS)作为偶氮染料的脱色产物很难被常规的厌氧-好氧染料废水处理工艺所去除。研究了未经驯化的活性污泥对TAHNDS的缺氧转化效果。结果表明,只有在特定的缺氧条件下(ORP在-50~-150 mV之间),TAHNDS才能被活性污泥所降解转化。当浓度在10~80 mg/L范围内,TAHNDS可在72 h内转化93%以上。加入100 mg/L的硝酸盐和0.64 mmol/L的氧化还原介体蒽醌-2-磺酸钠(AQS)可将40 mg/L的TAHNDS的转化时间从84 h缩短到36 h。光谱及HPLC-MS分析表明,TAHNDS在缺氧条件下主要是通过脱氨基和脱磺酸作用生成已知可好氧生物降解的3,5-二氨基-4-羟基萘-2-磺酸。因此,缺氧处理有望作为预处理工艺促进废水中TAHNDS的完全降解。  相似文献   

3.
Azizullah A  Richter P  Häder DP 《Chemosphere》2011,84(10):1392-1400
Synthetic detergents are among the commonly used chemicals in everyday life. Detergents, reaching aquatic environments through domestic and municipal wastewater, can cause many different effects in aquatic organisms. The present study was aimed at the toxicity evaluation of a commonly used laundry detergent, Ariel, using the freshwater flagellate Euglena gracilis as a biotest organism. Different parameters of the flagellate like motility, swimming velocity, cell shape, gravitactic orientation, photosynthesis and concentration of light harvesting pigments were used as end points for the toxicity assessment. No Observed Effect Concentration (NOEC) and EC50 values were calculated for the end point parameters at four different incubation times, i.e. 0, 6, 24 and 72 h. After 72 h incubation, swimming velocity of the cells was found to be the most sensitive parameter giving NOEC and EC50 values of 10.8 and 34 mg L−1, respectively. After 72 h exposure to the detergent, chlorophyll a and total carotenoids were significantly decreased in cultures treated with Ariel at concentrations of 50 mg L−1 and above while chlorophyll b significantly decreased at concentrations above 750 mg L−1. The maximum inhibitory effect on the quantum yield of photosystem II was observed after 24 h exposure and thereafter a recovery trend was observed. Motility, gravitaxis and cell shape were strongly impaired immediately upon exposure to the detergent, but with increasing exposure time these parameters showed acclimatization to the stress and thus the NOEC values obtained after 72 h were higher than those immediately after exposure.  相似文献   

4.
Hu XY  Fan J  Zhang KL  Wang JJ 《Chemosphere》2012,87(10):1155-1160
In this work, Bi4NbxTa(1−x)O8I photocatalysts have been synthesized by solid state reaction method and characterized by powder X-ray diffraction, scanning electron microscope and UV-Vis near infrared diffuse reflectance spectroscopy. The photocatalytic activity of these photocatalysts was evaluated by the degradation of methyl orange (MO) in aqueous solutions under visible light, UV light and solar irradiation. The effects of catalyst dosage, initial pH and MO concentration on the removal efficiency were studied, and the photocatalytic reaction kinetics of MO degradation as well. The results indicated that Bi4NbxTa(1−x)O8I exhibited high photocatalytic activity for the removal of MO in aqueous solutions. For example, the removal efficiency of MO by Bi4Nb0.1Ta0.9O8I was as high as 92% within 12 h visible light irradiation under the optimal conditions: initial MO concentration of 5-10 mg L−1, catalyst dosage of 6 g L−1 and natural pH (6-8), the MO molecules could be completely degradated by Bi4Nb0.1Ta0.9O8I within 40 min under UV light irradiation, and the photodegradation efficiency reaches to 60% after 7 h solar irradiation. Furthermore, the photocatalytic degradation of Bisphenol A (BPA) was also investigated under visible light irradiation. It is found that 99% BPA could be mineralized by Bi4Nb0.1Ta0.9O8I after 16 h visible light irradiation. Through HPLC/MS, BOD, TOC, UV-Vis measurements, we determined possible degradation products of MO and BPA. The results indicated that MO was degradated into products which are easier to be biodegradable and innocuous treated, and BPA could be mineralized completely. Furthermore, the possibility for the photosensitization effect in the degradation process of MO under visible light irradiation has been excluded.  相似文献   

5.
A method employing solid phase extraction followed by gas chromatography-mass spectrometry with negative chemical ionization has been developed for determination of ultratrace concentrations of perfluoroalkyl carboxylic acids in river water. The effects of the experimental parameters, such as the pH, additions of NaCl and an ion-pairing agent (tetraethylammonium bromide) and the kind of the elution agent, on the efficiency of the test acid extraction have been studied. The analyte extraction recoveries and the limits of detection and determination have been found. The method developed has been tested on determinations of perfluoroalkyl carboxylic acids in the waters of the two largest Czech rivers, Vltava and Labe (Elbe). The best extraction results have been attained without any alteration of the sample pH, with an addition of tetrabutylammonium bromide (a concentration of 50 μg mL−1 in the sample) and using methanol as the elution agent. Under these conditions, the recoveries of the test acids in the spiked real samples are within ranges from 60% to 104% and 53% to 111% for analyte concentration levels of 1.40 ng mL−1 and 0.14 ng mL−1, respectively, depending on the lengths of the perfluorinated chains of the acids. In general, the recovery decreases with increasing length of this chain. The method developed exhibits very low limits of detection and determination and the results are fully comparable with those obtained when using more expensive HPLC-MS/MS instrumentation. Typical values amount to tenths to tens of pg mL−1 and units to one hundred pg mL−1 for the limits of detection and determination, respectively; the measuring sensitivity increases with increasing length of the analyte chain. The analyzes of real samples from the Vltava and Elbe rivers have demonstrated that the results obtained are similar to the values published for contamination of the Elbe and other rivers in western and central Europe. The concentrations determined are of the order of units to tens of pg mL−1 and the C8-C10 acids occur most often.  相似文献   

6.
The gold nanoparticles (Au-NPs) are being increasingly used because of their huge diversity of applications, and consequently, elevated levels in the environment are expected. However, due to their physico-chemical properties and functionalization a high variety of Au-NPs can be found, and complete toxicological information for each type of Au-NPs still lacks, and even, the toxicological information for the same species is sometimes contradictory. Therefore, hazard assessment should be done case by case. Hence, the objective of this study was to obtain ecotoxicological information of the same Au-NPs in aquatic organisms and to find a rationale for Au-NPs toxicity. For such a purpose, bare and hyaluronic acid capped Au-NPs (12.5 nm) along with Au-NPs bulk material were tested on freshwater algae, Daphnia and zebrafish. Results showed that while gold nanoparticles were found to be harmless to the tested organisms, the soluble gold showed to be toxic to algae and Daphnia, with an LC50 between 1 and 2 mg L−1. Comparing our results with those gathered in the literature, it appears that a common hazard assessment of Au-NPs on the studied organisms can be elucidated.  相似文献   

7.
Liu H  Yu H  Giesy JP  Sun Y  Wang X 《Chemosphere》2007,66(11):2159-2165
HC Orange No. 1 (HCO1; 2-nitro-4′-hydroxydiphenylamine) (CAS No. 54381-08-7) is used as a color additive in hair dyes and can be released into aquatic environments in wastewater. In this paper, the effects of HCO1 on aquatic organisms were studied using a battery of toxicological tests. These included measuring immobilization of Daphnia magna, inhibition of zebrafish embryo development, and acute lethality in zebrafish and goldfish, which are different species belonging to different trophic levels. HCO1 was toxic to all of the organisms studied. In our experiments, HCO1 remarkably restrained the mobility of D. magna, which may cause subsequent death. The EC50 value for restrained the mobility of D. magna at 48 h was 1.54 mg HCO1 l−1. In addition, HCO1 showed toxicity in zebrafish and goldfish, where LC50values at 96 h were 4.04 and 5.37 mg l−1, respectively. The results also indicated that HCO1 remarkably retarded the development of zebrafish embryos, which may cause embryo abnormality and even lethality. The most sensitive toxicological endpoint in the development of the embryos was failure to hatch, which had an EC50 of 0.19 mg HCO1 l−1. These results indicated that HCO1 is a potential teratogen to zebrafish embryos. In addition, as HCO1 concentrations increased, the outcomes of each of these toxicity tests changed in a concentration-dependent manner. Together, the results revealed that HCO1 appears to be toxic to multiple different species of aquatic organisms. The EC50 (LC50) values contain sufficient discriminatory power for risk assessment of HCO1 in aquatic environments. Based on the present results, more efficient risk assessment procedures for HCO1 will be designed in the future, integrating more flexible testing methods into the testing schemes that employ only the necessary tools for each case.  相似文献   

8.
The study reports the accumulation, distribution and metabolism of technical endosulfan in Jenynsia multidentata. Adult females were exposed to acute sublethal concentrations (0.072, 0.288 and 1.4 μg L−1). After 24 h, fish were sacrificed and gills, liver, brain, intestine and muscle were removed. Results show that both isomers of technical-grade endosulfan (α- and β-) are accumulated in fish tissues and biotransformation to endosulfan sulfate occurs at all concentrations tested. Significantly differences in endosulfan accumulation were only found at 1.4 μg L−1 but not between the lowest concentrations. However a similar distribution pattern was observed at all exposure levels where liver, intestine and brain had the highest levels of α-, β-endosulfan and endosulfan sulfate. Moreover, liver and brain showed the highest endosulfan sulfate:α-endosulfan ratios due to high biotransfomation capacity. J. multidentata demonstrated to be a sensitive species under exposure to technical endosulfan and, therefore, could be used to assess aquatic pollution.  相似文献   

9.
Organic solvents, such as dimethylsulfoxide (DMSO) and methanol are widely used as vehicles to solubilise lipophilic test compounds in toxicity testing. However, the effects of such solvents upon innate detoxification processes in aquatic organisms are poorly understood. This study assessed the effect of solvent exposure upon cytochrome P450 (CYP)-mediated xenobiotic metabolism in Daphnia magna and zebrafish larvae (4 d post fertilisation). Adult D. magna were demonstrated to have a low, but detectable, metabolism of ethoxyresorufin in vivo and this activity was not modulated by pre-exposure to DMSO or methanol (24 h, up to 0.1% and 0.05% v/v, respectively). In contrast, the metabolism of ethoxyresorufin in zebrafish larvae was significantly reduced by both solvents (0.1% and 0.05% v/v, respectively) after 24 h of exposure. In zebrafish, these observed decreases in activity towards ethoxyresorufin were accompanied by decreased expression of a variety of genes coding for drug metabolising enzymes (corresponding to CYP1, CYP2, CYP3 and UDP-glucuronyl transferase [UGT] family enzymes), measured by quantitative PCR. Reduction of gene expression and CYP1 enzyme activities by methanol (0.05% v/v) in zebrafish larvae was partially reversed by co-exposure with Aroclor 1254 (100 μg L−1). Overall this study suggests that relatively low concentrations of organic solvents can impact upon the biotransformation of certain xenobiotics in zebrafish larvae, and that this warrants consideration when assessing compounds for metabolism and toxicity in this species.  相似文献   

10.
Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg−1), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg−1), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg−1) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH)6]2, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content.  相似文献   

11.
Perfluorinated chemicals (PFCs) have been used for many years in numerous industrial products and are known to accumulate in organisms. A recent survey showed that tissue levels of PFCs in aquatic organisms varied among compounds and species being undetected in freshwater zebra mussels Dreissena polymorpha. Here we studied the bioaccumulation kinetics and effects of two major PFCs, perfluorooctane sulfonic acid compound (PFOS) and perfluorooctanoic acid (PFOA), in multixenobiotic transporter activity (MXR) and filtration and oxygen consumption rates in zebra mussel exposed to a range of concentrations of a PCF mixture (1–1,000 μg/L) during 10 days. Results indicate a low potential of the studied PFCs to bioaccumulate in zebra mussel tissues. PFCs altered mussel MXR transporter activity being inhibited at day 1 but not at day 10. Bioaccumulation kinetics of PFCs were inversely related with MXR transporter activity above 9 ng/g wet weight and unrelated at tissue concentration lower than 2 ng/g wet weight suggesting that at high tissue concentrations, these type of compounds may be effluxed out by MXR transporters and as a result have a low potential to be bioaccumulated in zebra mussels. Oxygen consumption rates but not filtering rates were increased in all exposure levels and periods indicating that at environmental relevant concentrations of 1 μg/L, the studied PFCs enhanced oxidative metabolism of mussels. Overall, the results obtained in this study confirm previous findings in the field indicating that an important fraction of PFC accumulated in mussel tissues is eliminated actively by MXR transporters or other processes that are metabolically costly.  相似文献   

12.
Proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to study the response of zebrafish (Danio rerio) to increasing concentrations of bisphenol A (4,4′-(propane-2,2-diyl)diphenol, BPA). Orthogonal partial least squares discriminant analysis (OPLS-DA) was applied to detect aberrant metabolomic profiles after 72 h of BPA exposure at all levels tested (0.01, 0.1, and 1.0 mg/L). The OPLS-DA score plots showed that BPA exposure caused significant alterations in the metabolome. The metabolomic changes in response to BPA exposure generally exhibited nonlinear patterns, with the exception of reduced levels of several metabolites, including glutamine, inosine, lactate, and succinate. As the level of BPA exposure increased, individual metabolite patterns indicated that the zebrafish metabolome was subjected to severe oxidative stress. Interestingly, ATP levels increased significantly at all levels of BPA exposure. In the present study, we demonstrated the applicability of 1H-NMR-based metabolomics to identify the discrete nature of metabolic changes.  相似文献   

13.
Anthropogenically derived nitrogen (N) has a central role in global environmental changes, including climate change, biodiversity loss, air pollution, greenhouse gas emission, water pollution, as well as food production and human health. Current understanding of the biogeochemical processes that govern the N cycle in coupled human–ecological systems around the globe is drawn largely from the long-term ecological monitoring and experimental studies. Here, we review spatial and temporal patterns and trends in reactive N emissions, and the interactions between N and other important elements that dictate their delivery from terrestrial to aquatic ecosystems, and the impacts of N on biodiversity and human society. Integrated international and long-term collaborative studies covering research gaps will reduce uncertainties and promote further understanding of the nitrogen cycle in various ecosystems.  相似文献   

14.
Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC50 of 5 microg l(-1) for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 microg l(-1) azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F=2.75, P=0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F=15.33, P<0.001). Whilst causality cannot be directly attributed from these latter exposures, they provide an important illustration of the potential utility of esterase activity as a biomarker of environmental quality in this ecologically relevant sentinel species.  相似文献   

15.
A 1H-nuclear magnetic resonance (NMR) spectroscopy with multivariate analysis was applied to detect the toxicity of antiacetylcholinesterase insecticides, methomyl (methyl (1E)-N-(methylcarbamoyloxy)ethanimidothioate) and methidathion (3-(dimethoxyphosphinothioyl sulfanylmethyl)-5-methoxy-1,3,4-thiadiazol-2-one), using zebrafish (Danio rerio) and Chinese bleak (Aphyocypris chinensis). Generally, methomyl and methidathion have been believed not to highly accumulate in fish tissues. However, these pesticides showed their toxicity by altering patterns of whole-body metabolites in neurotransmitter balance, energy metabolism, oxidative stress, and muscle maintenance in low concentrations. We used Pearson correlation analysis to contextualize the metabolic markers in pesticide treated groups. We observed that the positive correlations of choline with acetate and betaine in untreated control were shifted to null correlations showing acetylcholinesterase specific toxicity. This research demonstrated the applicability and potential of NMR metabolomics in detecting toxic effects of insecticide with a modicum of concentrations in aquatic environment.  相似文献   

16.
Despite that the use of DDT has been restricted for more than 40 years to malaria affected areas, low doses of this pesticide and its metabolites DDE and DDD can be found in the environment around the world. Although it has been shown that these pollutants induce cell and DNA damage, the mechanisms of their cytogenotoxic activity remains largely unknown. This study looks into their possible genotoxic effects, at doses that can be found in body fluids, on human lymphocytes using the cytokinesis-block micronucleus assay and the comet assay. After exposure for 1, 6, and 24 h compounds p,p′-DDT (0.1 μg mL−1), p,p′-DDE (4.1 μg mL−1), and p,p′-DDD (3.9 μg mL−1) showed increase in DNA damage. The most significant results were observed at exposure period of 24 h where number of micronucleated cells increased from control 2.5 ± 0.71 to 23.5 ± 3.54, 13.5 ± 0.71, and 16.5 ± 6.36 for DDT, DDE, and DDD, respectively. Similar effect was observed using comet test where the percentage of DNA in comets tail increased from control 1.81 ± 0.16 to 17.24 ± 0.55, 11.21 ± 0.56 and 9.28 ± 0.50 for each compound, respectively. At the same time Fpg-comet assay failed to report induction of oxidative DNA damage of these pollutants. Additionally, the type of cell death was determined using diffusion assay and necrosis dominated. Our findings suggest that even at low concentrations, these pesticides could induce cytogenetic damage to human peripheral blood lymphocytes and in that manner have the impact on human health as well.  相似文献   

17.
Tris(4-chlorophenyl)methanol (TCP) and tris(4-chlorophenyl)methane (TCPMe) were determined in aquatic organisms and sediment by a method based on Soxhlet extraction, gel permeation chromatography, fractionation over silica and gas chromatography/mass spectrometry (GC/MS) analysis. TCPMe was identified as the 4-substituted isomer after synthesis of this compound. TCP could be determined by GC/MS with negative chemical ionistation (GC/NCI-MS) with a detection limit of 0.02 g kg(-1) and a recovery of 90%. TCP concentrations in marine mammals from the North Sea and Dutch Wadden Sea ranged from 0.2 to 2 mg kg(-1), and those in marine and freshwater fish samples from 0.005 to 0.4 mg kg(-1) on a lipid wt basis. TCP concentrations in two Rhine delta sediment samples were 1.2 and 3.0 microg kg(-1) dry wt, respectively. TCPMe concentrations, determined by GC/MS with electron impact (GC/EI-MS), were 10-50% of the TCP concentration in all samples analysed.  相似文献   

18.
Hu J  Wang D  Wang J  Wang J 《Chemosphere》2012,89(5):536-541
Although engineered nanoparticles (NPs) could negatively impact environmental organisms, the synergistic effect of NPs and other toxic substances, which could be more significant than that of NP alone, have seldom been examined. The effect of two common NPs, nano-CeO2 and nano-TiO2, on the toxicity of Pb was evaluated using Ceriodaphnia dubia (C. dubia) as the model organism. Standard EPA procedures were followed in the toxicity evaluation. The toxicity of bare NPs (without Pb) was first evaluated and safe doses (levels without causing lethal effect) of NPs were used in the synergistic studies. It was found that the overall toxicity of Pb in the system containing NPs was greater than that of Pb alone, as indicted by the reduced median lethal concentration (LC50) of soluble Pb. The sorption of Pb onto the NP, and the uptake of NPs in the gastrointestinal tract of C. dubia were validated. Therefore, the uptake of Pb-loaded NPs increased the exposure of C. dubia to Pb, resulting in the enhanced toxicity. Reducing the solution pH could shift Pb speciation and enhance the overall toxicity of Pb, with or without the presence of NPs.  相似文献   

19.
A 12-month active biomonitoring study was performed in 2008-2009 on a northern French river system using the freshwater mussel Dreissena polymorpha as a sentinel species. Allochtonous mussels originating from a reference site (Commercy) were caged at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle River basin. The main objective of the study was to characterize the influence of biotic (sex, food availability) and abiotic (temperature, chemicals) factors on the reproductive and energy reserve (glycogen, lipids) cycles of exposed mussels. Both cycles were markedly disturbed at the Bouy and Sept-Saulx sites where the lowest chlorophyll a levels were recorded during the study. At these sites, mussels obviously faced a negative energy balance, as confirmed by the impairment of their physiological state and byssal attachment. At other exposure sites, reproductive and energy reserves cycles were less impacted but were still dependent on the nutritional state of mussels. The latter appeared as a significant natural confounding factor in ecotoxicological survey performed in low polluted areas.  相似文献   

20.
Fumonisin B1 (FB1) is a secondary metabolite produced by Fusarium verticillioides or Fusarium proliferatum, which present in food and feed. It causes hazardous effects on human and animal health. A monoclonal antibody (mAb) against FB1 was produced and a simple, reliable and sensitive, competitive, indirect enzyme-linked immunosorbent assay (ci-ELISA) for detection of FB1 was developed and the experiment conditions were optimized. The coating concentration of FB1-ovalbumin (FB1-OVA) was 500 ng mL?1, the action concentrations of anti-FB1 mAb and goat anti-mouse IgG were 1.28 × 104 and 1:5000, respectively. The 50% inhibitory concentration (IC50) was 11 ng mL?1, with a detectable range of 1.25–250 ng mL?1, and a limit of determination (LOD) of 1.15 ng mL?1. The cross-reactivity (CR) of the antibody against fumonisin B2 (FB2) was 60.4, and <1% against deoxynivalenol (DON), aflatoxin B1 (AFB1), ochratoxin A (OTA) or zearalenone (ZEN). In spiked samples (250 ng g?1, 500 ng g?1, 1000 ng g?1), the mean recoveries ranged from 86.7 ± 5% to 102 ± 4%, and the coefficient of variation (CV) ranged from 3% to 10%. A survey of 96 corn samples from Bozhou, Fuyang, Bengbu, and Hefei, in Anhui province, China, was performed. Frequencies of FB1 contamination were 83.3%, 95.8%, 20.8% and 91.7%, and the mean concentrations of positive samples were 0.702 μg kg?1, 0.883 μg kg?1, 0.074 μg kg?1, and 0.276 μg kg?1, respectively. The results of this study suggest that the ci-ELISA developed in this study can be used to identify FB1 in corn, furthermore, further study is needed to investigate FB1 contamination in food and feed to prevent its harmful health effects.  相似文献   

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