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1.
The acute toxicity of copper and copper plus complexing agents to common guppy Lebistes reticulatus was studied for 96 h by a static bioassay technique. The addition of complexing agents viz. disodium salt of EDTA, citric acid, sodium thiosulphate and glycine in Cu2+ solutions caused a great decrease in the per-cent mortality as compared to that of Cu2+ test solutions alone. 10 mg/l of complexing agent was added in each copper concentration in all the test series. The 96 h LC50 values and 95% confidence limits in mg/l of Cu2+ plus were 1.23 (0.95…1.65) for Cu2+ alone; 4.30 (4.04 … 4.55) for Cu2+ plus EDTA; 1.94 (1.69 … 2.18) for Cu2+ plus citric acid; 3.44 (2.96 … 3.74) for Cu2+ sodium thiosulphate and 2.29 (2.22 … 3.02) for Cu2+ plus glycine.  相似文献   

2.
A report is given on laboratory investigations into model waters containing Cu2+-, Ni2+- or Zn2+-ions and tartrate, citrate, NTA or EDTA as complexing agents. There were determined residual concentrations of the metal ions at different shares of complexing agents, which are achieved by the precipitation with lime and chalk. Chalk is added in order to secure the required exess of calcium ions without causing an overalkalinization of the water. In the range of pH = 8…9, however, residual concentrations lower than 1 mg/1 are achieved only for copper ions in the presence of tartrate.  相似文献   

3.
Some aspects of the influence of copper speciation on toxicity for blue-green algae are reviewed. The experimental part concentrates on Oscillatoria redekei and Aphanizomenon gracile. The two investigated species produce strong extracellular copper complexing ligands: Oscillatoria redekei in the exponential and stationary growth phase, and Aphanizomenon gracile has a distinct detoxification capacity. The detoxification of copper by synthetic agents was investigated using ethylene-diamine-tetraacetic acid. Simultaneous addition of Cu2+ and Na2EDTA gives evidence for a slow complexation reaction. Hence an excess of Na2EDTA is necessary for a fast and complete detoxification of copper. Model calculations are reported to show that the precipitation of copper compounds is not probable under the conditions used.  相似文献   

4.
An integrated approach including chemical speciation analyses and microalgal bioassays was used to assess the impact of copper from copper mining on a coastal area in Northern Chile. Dissolved copper ranged from <1 microg l(-1) at reference sites to 48 microgl(-1) at sites close to the mine discharge. Dissolved copper at sites closest to the discharge always exceeded seawater complexing capacities determined by anodic stripping voltammetry (ASV), and consequently labile copper was always detected (1-37 microg l(-1)). Agreement between ASV-labile copper and copper retained by cation exchange (ALSA) columns was excellent. Measured labile copper also accurately predicted bioavailable copper determined by growth inhibition of Nitzschia closterium and enzyme inhibition in Dunaliella tertiolecta. Seawater from Caleta La Lancha had the highest dissolved and labile copper and was the most toxic to micro-algal growth and enzyme activity. Previous studies at this site confirmed it had the lowest level of biodiversity, suggesting that copper may have both direct and indirect effects on these communities.  相似文献   

5.
Application of Some Complexing Ion Exchangers for Copper Recovery from Natural Water and Wastewater The rational use of water resources is one of the urgent environmental control problems. These problems can be solved by the treatment of sewage. Removal of different non‐ferrous heavy metal ions from wastewater is of great importance. Besides, the selective complexing ion exchangers are of interest because of their good sorption properties. The present paper is devoted to the study of some complexing resins for copper recovery from natural water and sewage. The following carboxylic resins were studied: the cation exchangers KB‐2T, KB‐4 and the amphoteric ion exchangers ANKB 35, AMF‐2T, and AMF‐2S (manufacturer – “TOKEM” company, Kemerovo, Russia). The exchangers investigated differed from each other both by their functional groups and by their matrix physical structures. The copper recovery from CuCl2‐, CuSO4‐, and Cu(NO3)2‐solutions was studied in batch‐experiments (in presence of NaCl, Na2SO4, and NaNO3). The initial copper concentration in the solutions was 0.0002...0.008 mol/L; pH values were 1.0...5.0. After equilibrium (24 h) the resins were separated from the solution. The copper concentration in the solutions after the sorption was determined by the photometrical method with pyridylazoresorcin (λ = 500 nm). On the basis of the experimental data distribution ratio, the separation factors, equilibrium constants, and stability constants of copper complexes in the exchanger phase were calculated. It was found out in this work that the amphoteric ion exchanger AMF‐2T of macroreticular structure is the most effective for the copper sorption from sewage.  相似文献   

6.
While NTA or iron may stimulate phytoplankton photosynthesis on a short-term basis in the mesotrophic Lake of Lucerne, they impede this process in the eutrophic Greifensee. After a few days, however, this reaction tapers off. It is therefore highly unlikely that iron enters into play as a growth-limiting factor; the iron which inevitably gets into lakes through wastewater treatment plant effluents as a result of tertiary treatment (precipitation with Fe3+) will not have a long-term stimulating effect on plankton production. Both iron-through adsorption-and NTA-through chelation—reduce the supply of free ions of various metals, especially copper. Since, on the one hand, these free ions are needed for plankton growth and, on the other, have a toxic effect even in small quantities (μg/l), the medium can, through addition of iron or NTA, be disintoxicated or the trace metals limited, with corresponding increase or curtailment of algal production. The different patterns for the two lakes examined can be explained by the influence of the natural organic materials, found in each particular lake, on the free ions.  相似文献   

7.
The chemical speciation of dissolved copper was investigated in waters from the limno-corrals of the MELIMEX project and compared with speciation data from other Swiss lakes. Copper is complexed primarily by organic ligands having molecular sizes between 104 and 103 daltons. The mean concentration of the ligands is approximately 5×10−7 mole/mg DOC. The conditional stability constants (pH=8.8) are about 1011. An increased metal load did not induce an increase of binding ligands. A comparison of calculated Cu2+ concentration with corresponding copper contents in the biomass leads to the conclusion that organic ligands and pH are the most important factors in deciding the biological availability of copper. However the sorption capacity of the biomass depends as well on the variety of plankton species.  相似文献   

8.
Raritan Bay, which is adjacent to the New York metropolitan area, served as a study site to investigate the relationship between copper and lead concentrations in water and in seaweeds. Correlation coefficients of 0.98 for copper and 0.97 for lead indicate a high degree of correspondence between levels of these metals in water and in algal tissue. Concentration factors of 18.4 × 104 for copper and 8.2 × 104 for lead are among the highest reported to date.  相似文献   

9.
Acute toxicty tests (LT50) of copper or cadmium on the crustacean isopod Idothea baltica demonstrated differences between females, males, and juveniles. Copper appears to be more toxic than cadmium. the effects of chronic exposure to 5 μl−1 and 500 μl−1 copper or cadmium were evaluated from survival, body growth, and sex ratio in the first stages of juveniles development. While in juveniles 500 μl−1 significantly affected body growth, sex ratio, and survival, 5 μl−1 affected only survival. The study of the long-term effects of a pollutant on different demographic parameters in a species can serve to assess a ‘safe’ level of environmental contamination.  相似文献   

10.
Copper is more toxic to all life stages of the copepod Tisbe than cadmium. The most sensitive life stage of Tisbe to both copper and cadmium is the one-day-old nauplius. The resistance of larval stages of Tisbe increases with age (one-day-old nauplii 48h lc50=0.3142 mg Cu l?1. and 0.5384 mg Cd l?1, 0.3415 mg Cu l?1. and 0.645 mg Cd l?1. for five-days-old nauplii and 0.5289 mg Cu l?1. and 0.9061 mg Cd l?1. for ten-days-old nauplii. The two reproductive stages of Tisbe tested (females with ovigerous bands and females bearing the first ovigerous sac) demonstrated an increased sensitivity to metals and proved more sensitive than the ten-days-old copepodids (only females with ovigerous bands had a similar sensitivity to copper with the ten-days-old copepodids).  相似文献   

11.
The short-term toxicity of mercury, copper and zinc was studied using a freshwater pulmonate snail, Lymnaea luteola (LAMARCK ). The median period of survival increases with decreasing the toxicant concentration. The 96 h LC50 values and their confidence limits were 0.135 (0.112 … 0.186) ppm of Hg2+; 0.172 (0.118 … 0.355) ppm of Cu2+; and 6.13 (5.73 to 7.19) ppm of Zn2+. The relative potency ratio indicates that the Hg2+ ions were most toxic, followed by Cu2+ and Zn2+ ions.  相似文献   

12.
Malinovskii  D. N. 《Water Resources》2002,29(3):252-255
The regularities of Sr absorption by different Quaternary fluvioglacial sediments, containing groundwater within the Khibiny massif, have been studied. The studied sediments have been shown to adsorb Sr as a result of the cation exchange and complexing on the solid phase surface, which is responsible for the absorbing capacity of the sediments in the wide range of natural water pH. The base exchange capacity of Sr has been established to largely depend on the concentration of the macrocomponents (Ca2+ and Mg2+) in the groundwater. It has been noted that the migration mobility of Sr is low under the conditions of almost neutral water typical of the soil horizon in the studied area.  相似文献   

13.
The intertidal copeopod Tigriopus japonicus, which is abundant and widely distributed along the coasts of Western Pacific, has been suggested to be a good marine ecotoxicity testing organism. In this study, a series of experiments were conducted to investigate the reproducibility and variability of copper (Cu) sensitivity of T. japonicus so as to evaluate its potential to serve as an appropriate test species. To understand the seasonal variation of Cu sensitivity, individuals of T. japonicus were collected from the field in summer and winter, and subjected to standard 96 h acute (static renewal) toxicity tests. 96 h-LC50 values of T. japonicus collected from the two seasons were marginally different (p = 0.05), with an overall coefficient of variation (CV) of 33%. Most importantly, our results indicated that chronic Cu sensitivity of T. japonicus was highly reproducible. The CVs of intrinsic rates of increase in the population of the control and Cu treatment (10 μg Cu l−1) groups were only 10–11% between 10 runs of a standardised complete life-cycle test. Moreover, different Cu(II) salts generally resulted in a similar 96 h-LC50 value while Cu(I) chloride was consistently slightly less toxic than Cu(II) salts. Given such a high reproducibility of toxic responses, it is advocated to use T. japonicus as a routine testing organism.  相似文献   

14.
Summary: In Hungary a large proportion of the drinking-water demand is met by bank filtration. Especially the middle section of the Danube stretch is used for drinking-water supply, also for the capital Budapest (310 · 106 m3/a). The considerable pollutant load imported, anyhow, is increased by several Hungarian sources of contamination. The Danube has such a high self purifying capacity that, among other things, the annual COD-Mn load by the city of Budapest amounting to 140,000 t is degraded to such a level that the export of organic pollutants in the Danube from Hungary is not greater than the import. Heavy metals get into the bank filtrate through organic complexing agents. Also organochlorine compounds and their precursors were quantitatively determined. In Budapest water is treated with ozone, activated carbon and open high-rate filtration.  相似文献   

15.
Cadmium,zinc, copper,and barium in foraminifera tests   总被引：1，自引：0，他引：1  
The concentrations of cadmium, zinc, copper and barium have been determined on 2-mg samples of single-species foraminifera populations. Cleaning techniques were tested using North Atlantic core tops, and followed by a detailed downcore study for the last 30,000 years in South Atlantic core V22-174. Raw foram tests cleaned by crushing followed by ultrasonic removal of fine-grained material, and dissolved in a pH 5.5 acetate buffer, contain appreciable amounts of trace elements associated with ferromanganese and alumino-silicate contaminants. A reductive/complexing cleaning treatment reduces ferromanganese contamination by 1–2 orders of magnitude. Acetate buffers at pH 5.5 complex iron and raise the solubility of ferromanganese oxides; these buffers are unsuitable for separating carbonate lattice-bound trace elements from the fraction associated with ferromanganese phases. Improved mechanical and ultrasonic reductive cleaning combined with a mild dissolution in distilled water under 1 atm.PCO2 reduces contaminant levels another order of magnitude. The Cd and Zn concentrations (order 10?8 mole Cd/mole Ca and 10?5 mole Zn/mole Ca) of species with low surface area show an increase with decreasing isotopic temperatures. This increase is consistent with the increasing concentrations of these metals from low values in surface waters to higher values at depth. The variance of Cd and Zn over the last 30,000 years in the central South Atlantic is consistent with the probable variability of the dissolved trace elements at the calcification levels of the species analyzed. Cu and Ba are irreproducible and probably sensitive to residual contaminant phases. The trace element content of the tests differs from levels observed in a recent coprecipitation study. Foraminifera may be a significant vector in zinc cycling in the ocean.  相似文献   

16.
Through a power plant an inflow of considerably heated and very eutrophic water gets into the polymikt reservoir (volume h 15.1 · 106m3, 341 ha, MQ6 m3/s). Phosphorus is the limiting nutrient with a relatively high share from agricultural utilization. The spring maximum of phytoplankton is due to chlorophytes and diatoms, and the summer maximum is caused by cyanophyceae (up to 300 colonies/ml). It could be successfully controlled by copper sulphate. This treatment did not produce any negative effects in the free water (0.05 … 0.1 mg/l Cu2+) or in the sediment with a storage of about 1 t Cu per year. The construction of preimpoundment reservoirs, however, must be recommended for a lasting solution.  相似文献   

17.
This work describes the modification of silica gel with dimethylglyoxime, in order to prepare an effective sorbent for the preconcentration and determination of copper. The sorption capacity of dimethylglyoxime‐modified silica‐gel (DMGMS) was 71.37 mg g–1 and the optimum pH for the quantitative recovery of copper was found to be 5.0. The optimum flow rate, sorbent amount, and sample volume were 1 mL min–1, 300 mg, and 50 mL, respectively. 10 mL of 0.1 mol L–1 HCl was the most suitable eluent. The detection limit of copper was 6.0 ng mL–1. The recommended method, for the determination of copper, is simple and reliable, without any notable matrix effect and can be successfully applied to environmental water samples. Copper recovery in the range from 99–100% was obtained from seawater and thermal spring water using this method. The method was applied to standard reference materials, NIST‐1515 (apple leaves) and NIST‐1643e (simulated fresh water), for the determination of copper and the results were in good agreement with certified values.  相似文献   

18.
The toxic effects of various types of quaternary ammonium compound (QAC) upon a unicellular green alga (Chlorella sp.) and a duckweed (Spirodela oligorhiza) have been investigated. In general all types of QAC suppressed plant growth when present at concentrations above 10?5 M (ca 3–5 ppm). With the duckweed sublethal levels of QAC caused yellowing or browning of the frond margins and the production of smaller sized fronds whilst with Chlorella QACs affected both the size, shape and internal organization of the cell; death appeared to be due to disruption of the chloroplast structure.  相似文献   

19.
In the batch test with daily exchange of medium the effect of copper ions at 2.4 mmol/l (Ca2+ + Mg2+) over 10 d of exposure is investigated. The LT50 values and 95% confidence limits at 3.7, 2.1 and 1.0 ppm of Cu were 26.7 (23.6… 29.9), 47.5 (39.6… 57.0) and 101.5 (78.5… 130.7) h, respectively. The LC50 values of copper in ppm were 4.05 (24 h), 1.69 (48 h), 0.829 (9.96 and 0.776 (240 h).  相似文献   

20.
The influx of10Be into a globigerinid ooze core (CH72-02) from the eastern North Atlantic has been studied. This core contains a depositional record of the first 11 δ18O stages covering the last 423 ka. It is shown that the marine deposition of10Be is strongly influenced by the sedimentation of clays. Clay particles appear 10 times more efficient than the carbonate component as a carrier in bringing10Be to the bottom sediments. In core CH72-02, the deposition rates of10Be averaged over each oxygen-isotope stage for the past 11 stages show a scatter of ±40% about the mean value of 6.6 × 108 atoms cm−2 ka−1. However, after correction for changes in lithology, the data show that the production rate of10Be over the same period has varied no more than ±25%, and the variations are not systematic in that high or low10Be production appear to be associated with either cold or warm climates. On the time scale of this investigation (intervals of ca. 50 ka over the last 420 ka, with resolutions as fine as 10 ka for portions of the record), it is unlikely that the shielding effect of the solar wind has deviated by more than ±25% or the geomagnetic field intensity has deviated by more than a factor of 1.6 from their long-term averages.  相似文献   

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