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1.
In Germany, wastewater legislation requires all municipal and industrial leachate to be subjected to toxicity tests. However, no phytotoxicity tests using higher plants are currently included among the standard tests. Freshwater microalgae have been used in most phytotoxicity tests and have often been considered as surrogates for higher plants. However, microalgae often do not show the same sensitivity as higher plants and have major disadvantages for the testing of unmodified environmental samples. In the following study, we evaluated the suitability of the giant duckweed Spirodela polyrhiza for assessing the toxicity of a municipal landfill leachate and two leachates of copper mining residue. Duckweed static toxicity tests were performed, and frond number was the endpoint used to calculate EC50 values. Symptoms of stress (chlorosis, necrosis, root destruction, and colony breakup) were also recorded. The landfill leachate was toxic with EC50;96h values ranging from 1.3 to 2.7% leachate (v/v). Toxicity of the copper slag leachate was largely determined by the elution method used. Leachate obtained using conventional German leaching methods (S4-eluate) was not toxic to duckweed, whereas EC50 values for the pHstat4-eluate ranged from 3.2 to 4.2% leachate (v/v). The results demonstrate the suitability of S. polyrhiza for the testing of unmodified wastewater samples and provide further evidence for the addition of a duckweed toxicity test to the standard tests conducted in Germany.  相似文献   

2.
《Marine pollution bulletin》2014,78(1-2):172-176
A fungus, Aureobasidium pullulans, was isolated from marine biofilm and identified. A bioassay-guided fractionation procedure was developed to isolate and purify antifouling compounds from A. pullulans HN. The procedure was: fermentation broth—aeration and addition of sodium thiosulfate–graduated pH and liquid–liquid extraction—SPE purification—GC–MS analysis. Firstly, the fermentation broth was tested for its toxicity. Then it was treated with aeration and addition of sodium thiosulfate, and its toxicity was almost not changed. Lastly, antifouling compounds were extracted at different pH, the extract had high toxicity at pH 2 but almost no toxicity at pH 10, which suggested the toxicants should be fatty acids. The EC50 of the extract against Skeletonema costatum was 90.9 μg ml−1, and its LC50 against Balanus amphitrete larvae was 22.2 μg ml−1. After purified by HLB SPE column, the EC50 of the extract against S. costatum was 49.4 μg ml−1. The myristic and palmitic acids were found as the main toxicants by GC–MS.  相似文献   

3.
《Marine pollution bulletin》2012,65(12):2656-2662
In this paper, a highly selective sample cleanup procedure combining molecular imprinting technique (MIT) and solid-phase extraction (SPE) was developed for the isolation of malachite green in seawater and seafood samples. The molecularly imprinted polymer (MIP) was prepared using malachite green as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. The imprinted polymer and non-imprinted polymer were characterized by scanning electron microscope and static adsorption experiments. The MIP showed a high adsorption capacity and was used as selective sorbent for the SPE of malachite green. An off-line molecularly imprinted solid-phase extraction (MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of malachite green in seawater and seafood samples was also established. Finally, five samples were determined. The results showed that malachite green concentration in one seawater sample was at 1.30 μg L−1 and the RSD (n = 3) was 4.15%.  相似文献   

4.
The extraction efficiency of petroleum-derived dissolved organic matter (DOM) was examined for groundwater samples from an aquifer contaminated with crude oil. Five different types of extraction techniques were investigated to determine which method is best suited for the analysis of potentially toxic petroleum-derived DOM. The five types were a liquid-liquid extraction (LLE) with dichloromethane (DCM) and total petroleum hydrocarbons-diesel range (TPHd) with DCM (EPA method 3510C), and three solid-phase extraction (SPE) stationary phases that are routinely used for extraction of polar analytes from water. For the LLE and TPHd, that is selective for nonpolar compounds, the extraction efficiency of petroleum-derived DOM decreased downgradient as the petroleum-derived DOM becomes increasingly polar due to biodegradation. In contrast, the average extraction efficiency by the SPE methods was greater than 65% across the gradient. The results showed that SPE is more efficient for extracting petroleum-derived DOM at hydrocarbon-contaminated sites. The use of a method with greater extraction efficiency for partially oxidized hydrocarbons may prove useful in determining relationships between their composition and structure and potential for risks to human health or the environment.  相似文献   

5.
A solid‐phase extraction (SPE)‐gas chromatography (GC)‐mass spectrometry (MS) analytical method was developed for the simultaneous analysis of natural free estrogens and their conjugates in wastewater samples. Natural free estrogens and their conjugates in wastewater were successfully separated by the oasis hydrophilic‐lipophilic balance solid phase extraction (Oasis HLB SPE) method, and the conjugates were initially enzyme hydrolyzed by β‐glucuronidase or arylsulfatase from Helix pomatia prior to derivatization. N‐methyl‐N‐(tert‐butyldimethylsilyl)trifluoroacetamide (MTBSTFA) plus 1% tert‐butyldimetheylchlorosilane (TBDMCS) was chosen as the derivatization reagent, and the most appropriate conditions of derivatization were determined to be at 95°C for 90 min. The recovery ratios of nine target chemicals were determined by spiking them in 1 L of ultra‐purified water or the influent of a wastewater treatment plant (WWTP). The recovery ratios of six out of nine for the analytes ranged from 73.3–114.9% with relative standard deviations (RSD) from 1.6–19.9%. The established method was successfully applied to environmental wastewater samples which were collected from one municipal wastewater treatment plant (WWTP) in Osaka, Japan, for the determination of natural free estrogens and their conjugates. In the influent sample, E1, E2, E1‐3S, E3‐3S, and E1‐3G were detected at concentrations of 16.6, 9.6, 8.2, 21.9, and 3.2 ng L–1, respectively. However, only E1 was detected at a high concentration of 44 ng L–1 in the effluent sample, suggesting that it is the dominant natural free estrogen in the effluent.  相似文献   

6.
Bioremediation is intensively studied today as a treatment method for soil contaminated with chlorinated pesticides, chemicals counted among persistent organic pollutants. In the presented work, results of desorption kinetics study using consecutive Tenax TA solid phase extraction (SPE) were tested as predictors of 3‐wk anaerobic soil bioremediation effectiveness for chlorinated pesticides γ‐HCH, DDT, and methoxychlor. Field‐contaminated samples were used in these experiments, and conditions of bioremediation tests were based on previous research. Amounts of pesticides removed during bioremediation (43–98% of initial concentrations) were in most cases much larger (average ratio 1.37) than rapidly desorbing fractions estimated in SPE using two‐compartment model of desorption kinetics. The scatter of results was also considerable (standard deviation 0.45). However, there was a statistically significant correlation between amounts removed and rapidly desorbing fractions (R2 = 0.64), indicating a relationship between degradability and desorbability. Nonetheless, determination of rapidly desorbing fractions was considered rather a poor indicator of soil bioremediation efficiency for chlorinated pesticides. The total amounts of pesticides desorbed by Tenax in 72 h performed better in this respect (R2 = 0.73, fraction removed/desorbed = 1.10 ± 0.20, average ± standard deviation). Disappearance of DDT during bioremediation was accompanied by DDD formation but this was considerably lower than results expected from stoichiometry.  相似文献   

7.
Short-term tests of the acute toxicity of Cu2+ (from copper sulphate) to a freshwater ostracod, Cypris subglobosa SOWERBY were carried out at five different pH values from 5.5 to 8.5. The toxicity of copper abruptly decreased with an increase in pH of the Cu-containing medium. The 48 h EC50 value of Cu increased from 0.35 ppm at pH =5.5… 5.1 ppm at pH =8.5. The per cent survival, median period of immobilization (ET50), slope functions and the 95 per cent confidence limits were determined at each pH level. The direct correlation between EC50 value and pH indicated that the acute toxicity of Cu decreased as the pH increased from 5.5… 8.5.  相似文献   

8.
Sequential extraction procedures are widely used to characterize the different operational fractions with different potential toxicity of metals in environmental solid samples. The present work describes the application of different analytical approaches for sequential extraction of aluminum to evaluate its mobility, availability, and persistent chemical forms in sediment samples of different fresh water ecosystems (lake, canal, and river). The conventional BCR three‐stage sequential extraction procedure (C‐BCR) was modified at each stage, by applying ultrasonic device (U‐BCR), in order to shorten the required shaking time of 16 h for each three steps (excluding the hydrogen peroxide digestion in step 3, which was not performed with ultrasonic bath), could be completed in 40, 50, and 45 min, respectively. The aluminum in all extracts were determination by atomic absorption spectrometry using nitrous oxide – acetylene flame. The accuracy of results obtained from C‐BCR and proposed U‐BCR was verified with literature reported values of certified sediment sample (BCR 701). The overall recoveries of aluminum obtained by proposed U‐BCR were found in the range of 96.7–113% of those values obtained with C‐BCR for all fractions. Use of ultrasonic device, provided a large saving in extraction time relative to conventional shaking. It was observed that major part of Al in real sediment samples (80–83% of total Al) were bound to residual fraction. The acid soluble fraction of aluminum extracted by 0.11 mol/L CH3COOH has good correlation with aluminum content in corresponding water samples of each ecosystem.  相似文献   

9.
The chemical composition and toxicity of a water soluble fraction (WSF) of oil versus the underlying water after in situ burning (ISB), has been studied in a laboratory experiment. A system for allowing water sampling after ISB was developed. Seawater samples and oil were collected prior to and immediately after ISB, and chemical analysis was conducted. The chemical characterization of the water showed that the disappearance of water soluble oil components during ISB was insignificant. Acute toxicity tests with the marine copepod Calanus finmarchicus and Microtox® bioassay was performed to establish LC50/EC50 values of the water. The results were compared with regular WAF systems with unburned weathered oil, and indicated no increase in toxicity in the underlying water after ISB.  相似文献   

10.
以泥鳅（Misgurnus anguillicaudatus）、铜锈环棱螺（Bellamya aeruginosa）、河蚬（Corbicula fluminea）为受试生物,以死亡率、渗血率、体质量变化、行动迟钝率、挖洞率为测试指标,探究沉积物中Zn和Cd对底栖生物的21 d慢性毒性效应,并对鄱阳湖Zn和Cd的沉积物基准值进行了验证.结果表明,沉积物中Cd对底栖生物的毒性效应强于Zn,沉积物中Zn、Cd对泥鳅、铜锈环棱螺、河蚬的LC50（半数致死浓度）分别为644和61 mg/kg、751和54 mg/kg、652和81 mg/kg,EC50（半数效应浓度）值分别为526和49 mg/kg、589和35 mg/kg、474和45 mg/kg.经验证,沉积物Zn和Cd的TEL（临界效应浓度）、PEL（必然效应浓度）值比较合理,具有一定适用性,即当Zn、Cd的加标含量低于TEL值时,QTEL<1,不具有毒性;当加标含量高于PEL值时,QPEL>1,毒性明显.  相似文献   

11.
Natural estrogens from humans increasingly attract attention because of their strong endocrine disrupting potency. The discharge of sewage water is considered as the most important source of these endocrine disrupting chemicals (EDCs) in the environment. Therefore, a GC‐MS method was developed for the simultaneous analysis of six natural free estrogens and their sulfate conjugates in municipal wastewater, in which natural free estrogens and sulfate conjugates were successfully separated from an Oasis HLB solid phase extraction (SPE) cartridge with two different eluents, and the sulfate conjugates were then transformed to their corresponding free estrogens by acid solvolysis. Before the analysis with GC‐MS, samples were derivatized by N,O‐bis (trimethylsilyl) trifluoroacetamide (BSTFA) plus 1% trimethylchlorosilane (TMCS) at 80°C for 40 min. Satisfactory recoveries ranging from 64 to 112.3% were obtained by spiking ultra‐purified water, raw, and treated municipal wastewater with the six estrogens at 50, 100, and 50 ng/L, respectively. The method was successfully applied to wastewater samples from one WWTP, which suggested that E1 was the dominant natural estrogens in effluent and E3‐3S was one of the conjugates possibly occurring in the effluent.  相似文献   

12.
Biofilm formation is a key step during marine biofouling, the natural colonization of immersed substrata, leading to major economic and ecological consequences. Consequently, bacteria have been used for the screening of new non-toxic antifoulants: the adhesion of five strains isolated on three French locations was monitored using a fluorescence-based assay and toxicity was also evaluated. Nine biocides including commercial, natural and natural-derived products were tested. The commercial antifoulants, TBTO and Sea Nine showed low EC50 but high toxicity. The non-commercial products TFA-Z showed significant anti-adhesion activities and appeared to be non-toxic, suggesting a specific anti-adhesion mechanism. In addition, the strains could be classified depending on their sensitivity to the molecules used even if strain sensitivity also depended on the molecules tested. In conclusion, TFA-Z would be a promising candidate as non-toxic antifoulant and our results strengthen the need to perform antifouling bioassays with a panel of strains showing different response profiles.  相似文献   

13.
The influence of humic substances (HS) on the biodegradation of naphthalene, phenanthrene, and pyrene was studied. As a source of HS, water samples of a bog lake (Hohlohsee) were used. PAH degradation experiments, both in the presence and absence of HS were carried out. All investigated PAHs were degradable by the used bacterial mixed culture. A correlation between the number of aromatic rings of the PAHs and the influence of HS on biodegradation has been shown. Adding of HS led to a decrease in degradation rate in the case of naphthalene. By way of contrast, the presence of HS gave rise to an increase of degradation rate in the case of phenanthrene. The degradation processes of pyrene revealed a marked alteration in the presence of HS which could be deduced from the biochemical oxygen demand (t(1/2BODmax) values). With regard to the total turnover of the PAHs, there was no noticeable difference between degradation experiments with and without HS. Analyses of the HS after degradation experiments using liquid chromatography coupled with DOC detection (LC/OCD) verify that there was no formation of stable associations between HS and PAHs or their metabolites. The determination of the toxicity of the degradation media as luminescence inhibition against Vibrio fischeri (Photobacterium phosphoreum) showed no detoxification as a result of the presence of HS.  相似文献   

14.
Five‐step sequential extractions were employed to fractionation of Ni, Cr and Cu in soil polluted by anthropogenic activities and determine the mobility of the metals. Twelve samples were collected on an agricultural area that was located near an airport and intercity roads in Elazig‐Turkey. Exchangeable, organically bounded, carbonate bounded, adsorbed species on Fe and Mn oxides and residual species (except silicates) of Ni, Cr and Cu were extracted into solution by using CaCl2, Na4P2O7, Na2EDTA, NH2OH–HCl and HNO3–H2O2, respectively. Mobile metal concentrations in fractions and total recoverable in soils were determined by using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Total recoverable Ni, Cr and Cu concentrations were in the range of 40–119, 45–126 and 23–72 mg kg?1, respectively. It was observed that total concentrations of metals in some of the samples were higher than the permitted values. The sum of the mobile percentages of metals was found to be lower than 50%. The Ni, Cr and Cu percentages for exchangeable species are in the ranges of 0.18–1.64, 0.03–0.59 and 0.42–2.53%, respectively.  相似文献   

15.
Solar photocatalytic decolorization and detoxification of batik dye wastewater using titanium dioxide (TiO2) immobilized on poly‐3‐hydroxybutyrate (P(3HB)) film was studied. The effects of initial dye concentration, catalyst concentration, P(3HB) film thickness, and fabrication methods of the nanocomposite films were evaluated against methylene blue, a standard organic dye. It was observed that 0.4 g of P(3HB)‐40 wt% TiO2 removed 96% of the color under solar irradiation. P(3HB) and TiO2, mixed concurrently in chloroform followed by stirring for 24 h showed a more even distribution of the photocatalyst on the polymer surface and yielded almost 100% color removal. The photocatalytic films were able to completely decolorize real industrial batik dye wastewater in 3 h and induced a chemical oxygen demand (COD) reduction of 80%. Reusability of the 0.4 g P(3HB)‐40 wt% TiO2 film in decolorizing the batik dye wastewater was also possible as it gave a high consistent value of decolorization percentage (>80%) even after the sixth repeated usage. Recovery step of the photocatalysts was also not required in this simple treatment system. The decolorized batik dye wastewater had less/no toxic effects on mosquito larvae, Aedes aegypti, and microalgae, Scenedesmus quadricauda indicating simultaneous detoxification process along with the decolorization process.  相似文献   

16.
Leachate, ground-, and surface water from former ammunition sites and areas which are known to be contaminated by nitroaromatic compounds in Lower Saxony (Germany) were investigated in order to identify and quantify acidic nitroaromatic compounds (e.g., nitrobenzoic acids, aminonitrobenzoic acids, nitrophenols, and nitrocresols). Acidic and neutral nitroaromatic compounds were enriched by solid-phase extraction (SPE) on a polystyrenedivinylbenzene copolymer and routinely screened for acidic compounds by means of HPLC/photodiode array detection (HPLC/PDA). Qualitative and quantitative results obtained in this way were corroborated by proton nuclear magnetic resonance spectroscopy (1H-NMR). Validation data for the quantification procedure using this technique are given. The results show that all samples contaminated with 2,4,6-trinitrotoluene (TNT) and related compounds are also contaminated by acidic nitroaromatic compounds (e.g., 2,4-dinitrobenzoic acid, 3,5-dinitrophenol, and especially with 2-amino-4,6-dinitrobenzoic acid) in the μg/L range. This current work shows that 1 H-NMR allows the quantitative determination of protoncarrying analytes in mixtures after solid-phase extraction down to the upper ng/L range after addition of an internal standard to the SPE extract. This is even possible when reference compounds are not commercially available.  相似文献   

17.
An ultrafiltration methodology and the results of its application on Elbe river water are presented. Compared with other methods, Ultrafiltration allows fractionation of the molecular-weight fractions of DOC for higher volumes of solution in a shorter time. To characterize the molecular-weight fractions, the sum parameter DOC (β(DOC)) and the absorption coefficient at 254 nm a254 were measured, together with determination of a254/ β(DOC) for further characterization of the DOC fractions and to provide information about changes in parts of the UV-active substances of the total dissolved organic material. In the period May 1992 to November 1994, the DOC molecular-weight composition of 65 samples of Elbe river water were determined. At two sampling locations (Torgau-East and Meissen), the DOC content β(DOC) was approximately 6 mg/L. The high-molecular weight fraction (> 10000 g/mol) gave a mean of 13% of the total DOC content β0(DOC). The measurements showed that the molecular composition of DOC in the Elbe does not greatly differ. There was also no clear seasonal influence on the molecular-weight composition of the DOC content. During the period of investigation, the percentage part of β(DOC) and a254/β(DOC) of the high-molecular weight fraction of the total dissolved organic material increased, while the a254/β(DOC) values of the middle molecular-weight fraction remained fairly constant. The dependence of β(DOC) on discharge of the Elbe river is low. Changes in molecularweight composition of DOC were only observed during the steepest increase in river discharge during a flood event, with another spectrum of substances responsible for the increase in β(DOC) when compared with the β(DOC) for low or middle water level.  相似文献   

18.
The eddy covariance (EC) method was used in a 30‐month study to quantify evapotranspiration (ET) and vegetation coefficient (KCW) for a wetland on a ranch in subtropical south Florida. To evaluate the errors in ET estimates, the EC‐based ET (ETC‐EC) and the Food and Agricultural Organization (FAO) Penman–Monteith (PM) based ET (ETC‐PM) estimates (with literature crop coefficient, KC) were compared with each other. The ETC‐EC and FAO‐PM reference ET were used to develop KCW. Regression models were developed to estimate KCW using climatic and hydrologic variables. Annual and daily ETC‐EC values were 1152 and 3.27 mm, respectively. The FAO‐PM model underestimated ET by 25% with ETC‐EC being statistically higher than ETC‐PM. The KCW varied from 0.79 (December) to 1.06 (November). The mean KCW for the dry (November–April) season (0.95) was much higher than values reported for wetlands in literature; whereas for the wet (May–October) season, KCW (0.97) was closer to literature values. Higher than expected KCW values during the dry season were due to higher temperature, lower humidity and perennial wetland vegetation. Regression analyses showed that factors affecting the KCW were different during the dry (soil moisture, temperature and relative humidity) and wet (net radiation, inundation and wind speed) seasons. Separate regression models for the dry and wet seasons were developed. Evapotranspiration and KCW from this study, one of the first for the agricultural wetlands in subtropical environment, will help improve the ET estimates for similar wetlands. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

19.
Ecotoxicological studies, using the tropical marine diatom, Nitzschia closterium (72-h growth rate), were undertaken to assess potential issues relating to the discharge from an alumina refinery in northern Australia. The studies assessed: (i) the species’ upper thermal tolerance; (ii) the effects of three signature metals, aluminium (Al), vanadium (V) and gallium (Ga) (at 32 °C); and (iii) the effects of wastewater (at 27 and 32 °C). The critical thermal maximum and median inhibition temperature for N. closterium were 32.7 °C and 33.1 °C, respectively. Single metal toxicity tests found that N. closterium was more sensitive to Al compared to Ga and V, with IC50s (95% confidence limits) of 190 (140-280), 19,640 (11,600-25,200) and 42,000 (32,770-56,000) μg L−1, respectively. The undiluted wastewater samples were of low toxicity to N. closterium (IC50s > 100% wastewater). Environmental chemistry data suggested that the key metals and discharge are a very low risk to this species.  相似文献   

20.
Laboratory experiments were used to study the sensitivity of both male and female Daphnia magna to a toxic cyanobacterium, Microcystis aeruginosa. Male and female D. magna were fed with M. aeruginosa and a green alga (Scenedesmus obliquus) in different mixtures that included 0%, 25%, 50%, 75% and 100% Microcystis. Growth of both males and females declined with increasing proportion of Microcystis in the diet. Males were slightly less sensitive to Microcystis than females with EC50 for growth inhibition at 72% and 63% Microcystis in the diet, respectively. On monospecific Microcystis diet, mortality rates for males (0.16 d–1) and females (0.17 d–1) were similar. The reproductive rate of females was the most sensitive endpoint with an EC50 of 42% Microcystis in the diet, whereas population growth rates were the least sensitive (EC50 of 74% Microcystis). Microcystis in the diet severely depressed growth and reproduction in Daphnia and poses a severe threat to its survival in which only a switch in reproductive strategy might provide Daphnia a refuge to a Microcystis environment that gradually becomes uninhabitable.  相似文献   

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