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101.
用静水式试验方法评价和比较了两种钻井泥浆的水可溶部份对斑节对虾仔虾、罗氏沼虾仔虾、虾虎鱼和剑尾鱼等4种水生动物的急性毒性。结果表明:泥浆水溶性成分对班节对虾仔虾、罗氏沼虾仔虾、虾虎鱼和剑尾鱼的半数致死浓度均明显大于10000mg/L(1%),但斑节对虾仔虾对泥浆水可溶性成份的敏感性高于其余3种动物,适于钻井泥浆毒性试验。可以认为在试验条件下两种泥浆是无急性毒性的物质,但由于泥浆组成的复杂性,综合评价泥浆对水环境的影响时,需探讨其对底栖生物的影响。 相似文献
102.
Yogendra Verma 《洁净——土壤、空气、水》2004,32(6):429-433
Regeneration of partially amputated caudal fin was studied in freshwater fish Oreochromis mossambicus exposed to sublethal concentrations of zinc (5.0 mg L—1 and 10.0 mg L—1) under ambient laboratory conditions over a period of 20 days. Caudal fin regeneration was measured on 5th, 10th, 15th and 20th day of exposure and after amputation. Significant ( p < 0.05) retardation in fin regeneration was observed on day 5th and 10th in fish exposed to the nominal concentration of 5.0 mg L—1 Zn, while retardation was found highly significant ( p < 0.01) at all the observations in 10.0 mg L—1. The maximum inhibition in caudal fin regeneration (20.8 % and 24.3 %) was found during the initial observation at both of the concentrations (5.0 mg L—1 and 10.0 mg L—1) of zinc exposure. Later on the regeneration rate was almost as good as in the control group. Thus in this study fin regeneration was significantly inhibited at all time points following Zn exposure as a detrimental effect of Zn to fish. This study demonstrates that fish caudal fin regeneration is a simple assay, sensitive and easy to perform, and can serve as a model to determine the toxicity of pollutants in aquatic environment. 相似文献
103.
锗对两种微藻的毒性及其在细胞中的累积 总被引:2,自引:1,他引:2
钝顶螺旋藻Spriulina platensis (Cyanophyceae)和盐生杜氏藻Dunaliella salina (Chlorophyceae)暴露在不同浓度锗的培养液中,研究了锗对它们的毒性及锗在藻细胞中的累积,结果表明,锗对S.platensis的毒性较D.salina大。在培养浓度范围内,S.Platensis中的总锗含量与培养介质中的锗含量关系不大。锗在S.platensis中的分布较均匀且呈剂量效应,在D.salina中,总锗含量随着培养液中锗含量的增加而增加,锗在细胞中的分布以氨基酸-碳水化合物和蛋白质中为主,脂类中含量则较低,上述差异反映了灌类在生理特性上的不同,研究表明,当藻类暴露在含锗介质中时,可吸收累积一定量的锗并结合到细胞内的大分子物质中,从而达到降低锗毒性的作用。 相似文献
104.
The toxic effects of the water accommodated fraction (WAF) of a natural gas condensate on the larvae of five brooding coral species of the Family Pocilloporidae were examined in short term (96 h) bioassays. Lethality was observed in some larvae of Seriatopora hystrix and Seriatopora guttatus upon exposure to high concentrations of the condensate WAF, while those of Stylophora pistillata, Pocillopora damicornis and Pocillopora verrucosa did not experience mortality. Furthermore, increasing concentrations of WAF produced either delayed or impeded metamorphosis for all species except P. damicornis. Growth of juveniles, exposed to different WAF treatments for 96 h during their larval/early juvenile stages, was measured after 30 d. Marked decrease in subsequent growth rate (polyp count) was observed for S. hystrix, S. guttatus and S. pistillata with increasing WAF concentration. The results showed differential susceptibility of larvae of closely related coral species to oil stress, with the following sensitivity ranking: S. guttatus>S. hystrix>S. pistillata>P. verrucosa>P. damicornis. Oil exposure during the planktonic, larval stage of susceptible corals can adversely affect survivorship, recruitment and/or subsequent colony growth, thereby having profound consequences for the abundance of these corals in space and time. 相似文献
105.
Adsorption and oxidative transformation processes critically affect the mobility and toxicity of arsenic (As) in the environment. In this study, the detoxification of arsenite through adsorption and oxidation by pyrolusite was systematically investigated. Disappearance of aqueous As(III) in the solution can be efficiently achieved using pyrolusite. The As(III) oxidative transformation product arsenate or As(V) was obtained both in the solution and on the pyrolusite surface. The arsenic species adsorbed on pyrolusite exist in two forms: As(III) and As(V). Furthermore, over 64.8% of the adsorbed As cannot be desorbed. They were fixed more stably in the structure of the mineral to achieve a safer removal. Lower As(III) initial concentration increased As(III) detoxification rates. Elevating the reaction pH from 4.5 to 7.9 elicited a slight effect on the disappearance rate of As(III). Efficient As(III) detoxification can be achieved by pryrolusite within the studied pH range. The addition of low‐molecular‐weight carboxylic acids decreased the detoxification rate of As(III) through competition for active sites on pyrolusite. Co‐existing divalent metal ions, such as Ca2+, Ni2+, and Mn2+, also decreased the detoxification rate of As(III). However, the trivalent ion Cr3+ largely increased the detoxification rate through co‐precipitation and adsorption processes. 相似文献
106.
Produced water (PW) discharged from offshore oil industry contains chemicals known to contribute to different mechanisms of toxicity. The present study aimed to investigate oxidative stress and cytotoxicity in rainbow trout primary hepatocytes exposed to the water soluble and particulate organic fraction of PW from 10 different North Sea oil production platforms. The PW fractions caused a concentration-dependent increase in reactive oxygen species (ROS) after 1 h exposure, as well as changes in levels of total glutathione (tGSH) and cytotoxicity after 96 h. Interestingly, the water soluble organic compounds of PW were major contributors to oxidative stress and cytotoxicity, and effects was not correlated to the content of total oil in PW. Bioassay effects were only observed at high PW concentrations (3-fold concentrated), indicating that bioaccumulation needs to occur to cause similar short term toxic effects in wild fish. 相似文献
107.
108.
Programs for evaluating proposed discharges of dredged material into waters of the United States specify a tiered testing and evaluation protocol that includes performance of acute and chronic bioassays to assess toxicity of the dredged sediments. Although these evaluations reflect the toxicological risks associated with disposal activities to some degree, analysis activities are limited to the sediments of each dredging project separately. Cumulative risks to water column and benthic organisms at and near the designated disposal site are therefore difficult to assess. An alternate approach is to focus attention on the disposal site, with the goal of understanding more directly the risks of multiple disposal events to receiving ecosystems. Here we review current US toxicity testing and evaluation protocols, and describe an application of ecological risk assessment that allows consideration of the temporal and spatial components of risk to receiving aquatic ecosystems. When expanded to include other disposal options, this approach can provide the basis for holistic management of dredged material disposal. 相似文献
109.
Sulfate-reducing bacteria (SRB) HSR1, HSR4, and HSR14 isolated from the salt pans of Goa grew best at 90-100/1000 salinity on substrates like formate, acetate, lactate, butyrate, ethanol and benzoate. They were gram negative, non-sporulating, non-motile rods lacking in desulfoviridin and cytochromes. Examination of these isolates for heavy metal tolerance and response studies in terms of growth and sulfate-reducing activity (SRA) were carried out using HgCl2 and Pb(NO3)2 at final concentration of 50, 100, and 200 and 100, 200 and 500 microg ml(-1) respectively. With Hg, HSR1 showed approximately 80% of the control's growth at 100 and 200 microg ml(-1) but SRA reached only 60% of the control values at the end of 14 days. HSR14 could reach >100% of the control's growth at 200 microg ml(-1) but the SRA reached only up to 60% of the control without metal at 100 microg ml(-1). Though the concentration of Pb was double that of Hg, HSR4 could grow and respire better than the control, the growth being stimulated by 160% and respiration by 170% in the presence of 500 microg ml(-1) of Pb(NO3)2. It is probable that some hypersaline SRB are more tolerant to heavy metals than the mesohaline counterparts and could be more effectively used for precipitating these metals in bioremediatory measures. Further examination of their responses to varied concentration of metals under different salinities would indicate their range of applicability. 相似文献
110.
Photoenhanced toxicity of polycyclic aromatic hydrocarbons (PAH) is well demonstrated in laboratory and in a few in situ studies. Effects have been observed for multiple taxa and toxicological endpoints, and the mechanism of toxic action has been described. However, this phenomenon is ameliorated by physical, chemical and biotic factors. The ecological relevance of PAH phototoxicity remains uncertain; it should not be used for environmental management decisions unless its ecological relevance is firmly established, and then only as part of a weight of evidence determination. 相似文献