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1.
The lethal toxicity of mixtures of Zn2+ —Ni2+, Cu2+ —Ni2+ and Zn2+ —Cu2+ —Ni2+ to common guppy at 21£C in hard water (total hardness = 260 mg/l as CaCO3) was studied under static bioassays test conditions with renewal of the test solutions every 24 h. The heavy metals were tested separately and in mixtures. The 48 h median lethal concentrations (LC50) for individual salts were 75 mg/l Zn2+, 37 mg/l for Ni2+ and 2.5 mg/l for Cu2+. Concentrations were expressed in “toxic units” by taking them as proportions of LC50 values. Experiments showed that in the Zn2+-Ni2+ mixture, when Ni2+ was more in proportion, the toxicity was more than additive. The 48 h LC50 value and 95% confidence limits in the Ni2+-Cu2+ mixture were 0.684 (0.484 … 0.807) toxic units and the mixture produced more than the additive toxicity (synergism.). The LC50 value and its 95% confidence limits in a Zn2+?Cu2+?Ni2+ mixture also suggested that the mixture was again strictly additive. The results indicate that heavy metallic mixtures would pose a greater toxicological danger to fish than the respective individual metals.  相似文献   

2.
Static bioassay acute toxicity tests of Zinc, Copper and Mercury were conducted to determine the median lethal concentrations (LC50s) of a freshwater teleost Channa marulius (HAM .) The 96 h LC50 and 95% confidence limits for Zn2+ were 25.61 (24.13 … 27.12) mg/l; 0.90 (0.80 … 1.038) mg/l; for Cu2+ and 0.314 (0.257 … 0.371) mg/l for Hg2+. However, these values decreased at 240 h of exposure and were: 21.09 (18.29 … 24.60) mg Zn2+/l; 0.66 (0.568 … 0.841) mg Cu2+/l; and 0.131 (0.103 … 0.158) mg Hg2+/l. The relative potency ratio of Zn/Hg, Zn/Cu and Cu/Hg suggests that fish were most sensitive to Hg, followed by Cu and Zn ions. The acute toxicities of mixtures of Zn2+?Cu2+; Zn2+?Hg2+, Cu2+?Hg2+ and Zn2+?Cu2+?Hg2+ up to 48 h of exposure were also investigated. The additive index and ranges for Zn2+?Cu2+ were ?0.241 (-0.577 … 0.054); 0.056 (-0.269 … 0.475) for Zn-Hg; 0.285 (-0.043 … 0.718) for Cu-Hg; and -0.542 (-1.215 … 0.005) for Zn-Cu-Hg. All the mixtures tested showed a greater than additive toxicity because index ranges overlapped zero.  相似文献   

3.
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   

4.
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   

5.
In the daily exchange of the medium with only 7.1 mg/l Ca2+ and 0.7 mg/l Mg2+ during the batch experiment the LC50,96h for Cyprinus carpio is 0.063 mg/l Cu2+ and 3.12 mg/l Zn2+ at water temperatures of 11 to 14°C. Significant differences in mortality as referred to the LC50,12h occur for copper only after 72 h of exposure and for zinc after 48 h of exposure. The values of LC50,96h are clearly lower for both metals in the investigations described than most data given in literature for different fish species.  相似文献   

6.
In this work, 8‐hydroxyquinoline is used as the active sites in cross‐linked chitosan beads with epichlorohydrin (CT‐8HQ). The CT‐8HQ material was shaped in bead form and used for heavy metal removal from aqueous solution. The study was carried out at pH 5.0 with both batch and column methods and the maximum adsorption capacity of metal ions by the CT‐8HQ was attained in 4 h in the batch experiment. The adsorption capacity order was: Cu2+ > Ni2+ > Zn2+ for both mono‐ and multi‐component systems with batch conditions. From breakthrough curves with column conditions, the adsorption capacity followed the order Cu2+ > Zn2+ > Ni2+ for both mono‐ and multi‐component systems. The CT‐8HQ beads maintained good metal adsorption capacity for all five cycles with absorbent restoration achieved with the use of 1.0 mol L–1 HCl solution, with 90% regeneration.  相似文献   

7.
This study aims to remove of Cu2+, Cd2+, and Pb2+ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion‐exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (qmax) were calculated as 0.478, 0.358, and 0.280 mmol g?1 for Cu2+, Cd2+, and Pb2+, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L?1 metal concentration was determined as 0.200, 0.167, and 0.155 mmol g?1 for Cu2+, Cd2+, and Pb2+ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g?1 for Cu2+, Cd2+, and Pb2+ ions, respectively, when initial metal concentration was 0.50 mmol L?1. In the multi‐metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu2+ > Cd2+ > Pb2+. In the presence of 100 mmol L?1 H+ ion, the order of ion‐exchange affinity with H+ was found as Cu2+ > Cd2+ > Pb2+. The adsorption kinetics were also found to be well described by the pseudo‐second‐order and intraparticle diffusion models. Two different rate constants were obtained as ki1 and ki2 and ki1 (first stage) was found to be higher than ki2 (second stage).  相似文献   

8.
The present investigation is designed to work out the isolated and in-combination effects of Zn2+, Cr6+ and Ni2+ to a fish Mystus vittatus. From all the 12 combinations, 6 are antagonistic and 6 are synergistic. The combination Cr/Ni is highly synergistic while combination (Cr + Ni)/Zn is highly antagonistic in nature. The possible mechanisms responsible for antagonistic and synergistic combinations have been discussed and indicated as the occupation of critical receptor sites by less toxic metal (antagonism) or intrinsic affinity of the individual metal for the critical site or relative concentration and distribution of the metals within the target organ site (synergism). The results drawn can be indicated in terms of the effective concentration required to reach a particular level for a particular biological end point and can be expressed as follows.  相似文献   

9.
In batch experiments for 6 to 48 h, individuals of Cyprinus carpio (2 g individual weight) were exposed to mixed solutions of copper and zinc sulphate: pH = 6.3, temperature 15 °C, 6.8 mg/l O2, 7.1 mg/l Ca2+, 0.7 mg/l Mg2+. The LC50 for the individual substances on exposures of 24 and 48 h amount to 9.04 and 7.28 mg/l, resp., of Zn and 0.11 and 0.095 mg/l, resp., of Cu. The sum of the biological activity of the two kinds of metal ions is assessed according to MARKING'S index: at low concentrations of the mixed solutions the two metals show an additive effect, at higher concentrations a synergistic effect occurs.  相似文献   

10.
Inorganic industrial waste landfills have the potential to contaminate subsurface groundwater supplies through migration of leachates down to the water table and into groundwater aquifers, despite the use of compacted low permeability clay or polyethene liners. This paper aims the removal of Cu2+ and Zn2+ in the leachate from an industrial waste landfill using natural materials (natural zeolite, expanded vermiculite, pumice, illite, kaolinite, and bentonite) as a liner material. Cu2+ and Zn2+ concentrations for all treatments decreased during the process. Of all the different natural materials, natural zeolite, expanded vermiculite and pumice, with bentonite, were effective in removing Cu2+ and Zn2+ present in the leachate. However, the use of illite and kaolinite with bentonite as liner materials could be of disadvantage in Cu2+ and Zn2+ removal from leachate. The adsorption kinetic models were also tested for the validity. The second order kinetics with the high correlation coefficients best described adsorption kinetic data.  相似文献   

11.
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   

12.
The relationship between light acclimation and Cu2+ tolerance was studied in two populations of Fucus serratus known to be naturally non-tolerant and tolerant to Cu2+. Acclimation to high irradiances increased the photosynthetic tolerance to Cu2+. The xanthophyll cycle was apparently not involved in protecting the photosynthetic apparatus against Cu2+ toxicity, as results showed that Cu2+ did not induce dynamic photoinhibition. The higher photosynthetic Cu2+ resistance of high light algae did not result in increased growth. The excess energy acquired by high light-adapted algae appeared to be utilized in Cu2+ defense mechanisms in the Cu2+ non-tolerant population. The polyphenol content of the algae was reciprocal to the CuT content, suggesting that polyphenol may be the primary Cu2+ defense of non-tolerant low light algae, acting through secretion and extracellular chelating of Cu2+, while the compounds do not seem to be involved in the primary Cu2+ tolerance mechanism in Cu2+ tolerant algae.  相似文献   

13.
Low cost adsorbents were prepared from dried plants for the removal of heavy metals, nitrate, and phosphate ions from industrial wastewaters. The efficiency of these adsorbents was investigated using batch adsorption technique at room temperature. The dried plant particles were characterized by N2 at 77 K adsorption, scanning electron microscopy, energy dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, and phytochemical screening. The adsorption experiments showed that the microparticles of the dried plants presented a good adsorption of heavy metals, phosphate, and nitrate ions from real wastewaters. This adsorption increased with increasing contact time. The equilibrium time was found to be 30 min for heavy metals and nitrate ions and 240 min for phosphate ions. After the adsorption process, the Pb(II) concentrations, as well as those of Cd(II), Cu(II), and Zn(II) were below the European drinking water norms concentrations. The percentage removal of heavy metals, nitrates, and phosphates from industrial wastewaters by dried plants was ~94% for Cd2+, ~92% for Cu2+, ~99% for Pb2+, ~97% for Zn2+, ~100% for ${\rm NO}_{{\rm 3}}^{{-} } $ and ~77% for ${\rm PO}_{{\rm 4}}^{3{-} } $ ions. It is proved that dried plants can be one alternative source for low cost absorbents to remove heavy metals, nitrate, and phosphate ions from municipal and industrial wastewaters.  相似文献   

14.
The reduction in light emission of the marine bacterium Vibrio fischeri used in the standard Microtox® bioassay was measured for the metals copper and mercury. The concentration at which the light emission was reduced by 50% (EC50) was determined to be (3.43 ± 0.83) μmol/L for Cu2+ and (0.66 ± 0.01) μmol/L for Hg2+. The reduction of the toxicity of these metals by humic and fulvic acids were studied using IHSS Standard and Reference Materials. Copper toxicity was reduced 17...20% by the soil and peat fulvic acids and 9...20% by the aquatic fulvic acids. While there appeared to be little difference in the reduction of Cu toxicity by fulvic acids from soils, peats, or aquatic systems, Hg toxicity was reduced 3.6...7.3% by the soils and peats, while aquatic fulvic acids reduced Hg toxicity 14...16%. Soil fulvic acids appear to have significantly less capacity to reduce Hg toxicity than Cu toxicity. Humic acids had much higher reductions of Cu toxicity (44...124%) compared to the fulvic acids, with little difference between aquatic and soil or peat humic acids, 44...124% and 67...100%, respectively. However, humic and fulvic acids, regardless of origin, had approximately the same effect on Hg toxicity with 3.5...16% reduction by fulvic acids and 8...20% reduction by humic acids. Unlike the fulvic acids, no clear trend was observed relative to origin of the humic acids. There was no correlation between percent reduction of Cu or Hg toxicity by the organic compounds and copper binding capacity (CuBC), C/N ratio, or carboxyl content of the materials. Examination of natural organic matter (NOM) isolated by reverse osmosis techniques from three water sources had reductions of both Cu and Hg toxicity that were most similar to the Suwannee River and Nordic fulvic acids.  相似文献   

15.
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   

16.
Groundwater quality in Ma’an area was evaluated for its suitability for drinking and agricultural uses by determining the main physical and chemical properties during a 1 year survey study (August 2009 to August 2010). Several samples were collected from ten different wells and analysed for temperature, pH, conductivity, total dissolved solids, total hardness, major cations (Ca2+, Mg2+, Na+ and K+), major anions (HCO3 ?, Cl?, NO3 ?, SO4 2?, F? and Br?) and trace metals (Fe2+, Al3+, Mn2+, Cu2+, Zn2+, Pb2+ and Cd2+). The general chemistry of water samples was typically of alkaline earth waters with prevailing bicarbonate chloride. The results showed great variations among the analyzed samples with respect to their physical and chemical parameters. However, most values were below the maximum permissible levels recommended by Jordanian and WHO drinking water standards. The quality assessment shows that in general, the GW in the study area is not entirely fit for direct drinking with respect to EC, and Pb2+. According to the residual sodium carbonate and sodium adsorption ratio, the water in the studied wells can be used for irrigational purposes.  相似文献   

17.
Three fluorinated bipyridine ligands have been designed and synthesized as chelating agents for the extraction of metal ions in supercritical CO2 (sc‐CO2). The ligand solubilities in sc‐CO2 were investigated at different temperatures and pressures, and the measured data have been correlated using a semiempirical model. The calculated results showed satisfactory agreement with the experimental data. Based on these data, metal ion extraction with the three compounds as chelating agents in sc‐CO2 was performed from spiked filter paper, whereby ligand 1 showed the highest extraction efficiency, especially for Ni2+ and Cu2+. The extraction constants, Kex, of the three chelating ligands were seen to increase with increasing extraction efficiency for the same metal ion in the same extraction system.  相似文献   

18.
A new sorbent was prepared by loading rhodamine B on Amberlite IR‐120. Various physico‐chemical parameters such as effects of adsorbate concentration, contact time, pH, and temperature on the sorption of the dye have been studied. Thermodynamic parameters (ΔH° and ΔS°) were also evaluated for the sorption of dye. Kinetic studies revealed that the sorption of the dye was best fit for pseudo‐second‐order kinetic. The metal ion uptake in different solvent systems has been explored through column studies. On the basis of distribution coefficient (Kd), some heavy metal ions of analytical interest from binary mixtures have been separated. The limit of detection (LOD) for the Ni2+ and Fe3+ metal ions was 0.81 and 0.60 µg L?1, and the limit of quantification (LOQ) was found to be 2.72 and 2.0 µg L?1. This sorbent has also been successfully applied in the analysis of multivitamin formulation. The applicability of the modified resin in the separation of heavy metals constituting real and synthetic samples has been explored.  相似文献   

19.
Three techniques for obtaining soil water solutions (gravitational and matrical waters extracted using both in situ tension lysimeters and in vitro pressure chambers) and their later chemical analysis were performed in order to know the evolution of the soil‐solution composition when water moves down through the soil, from the Ah soil horizon to the BwC‐ or C‐horizons of forest soils located in western Spain. Additionally, ion concentrations and water volumes of input waters to soil (canopy washout) and exported waters (drainage solutions from C‐horizons) were determined to establish the net balance of solutes in order to determine the rates of leaching or retention of ions. A generalized process of sorption or retention of most components (even Cl?) was observed, from the soil surface to the C‐horizon, in both gravitational and matrical waters, with H4SiO4, Mn2+, Na+, and SO42? being the net exported components from the soil through the groundwater. These results enhance the role of the recycling effect in these forest soils. The net percentages of elements retained in these forest soils, considering the inputs and the outputs balance, were 68% K+, 85% Ca2+, 58% Mg2+, 7% Al3+, 5% Fe3+, 34% Zn2+, 57% Cl?, and 20% NO3?, and about 75% of dissolved organic carbon was mineralized. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

20.
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