Dissertation > Environmental science, safety science > The basic theory for the Environment and Science > Environmental Biology > Environmental zoology

The Toxic Effect of Hg2+、Ni2+、Cu2+、Zn2+ and the Yellow River Water Sample on Tetrahymena Thermophila BF5

Author WangYeQiu
Tutor MaZhengXue
School Northwest Normal University
Course Ecology
Keywords Tetrahymena thermophila Heavy metal Yellow River water samples Acute Toxicity Joint toxicity
CLC X174
Type Master's thesis
Year 2008
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In this paper, heavy metals Hg 2 Ni 2 the of Cu 2 and the Zn 2 and the Yellow River water samples thermophilic Tetrahymena (Tetrahymena thermophila) BF5 toxic effects. The results show that: (1) Tetrahymena microbial growth in line with the typical \suppression. (2) In the acute toxicity study of heavy metal ions, Hg 2 Ni 2 Cu 2 and Zn 2 24h IC50 Tetrahymena are: 5.66,17.78,25.47,26.30 mg · L-; the 48h IC50 of are: 5.02,17.34,22.75,25.29; the 72h IC50 of: 4.83,16.52,21.43, 23.93mg · L-1; 96h of the IC50: 4.63,15.74,19.91,23.28 mg · L-1. Toxicity of four heavy metals Tetrahymena order the Hg 2 Ni 2 Cu 2 > Zn 2 , and the IC50 values ??of the four heavy metals smaller with time. (3) the joint toxicity study of heavy metal ions, using the toxic unit method (TU), mixed toxicity index (MTI), the additive index method (AI), the V-value method, and the combined effects of coefficient (K) five kinds methods to evaluate, in different proportions, there are some differences in the type and strength of the combined effects; different evaluation methods, the ratio of the same, the combined effect results there are also differences. Overall, Hg 2 -Ni 2 and of Hg , 2 Ni 2 -Zn < 2 -Cu 2 together for the first antagonistic toxic than 1:1, the concentration ratio of 1:1 are antagonism; Hg -Ni sup > 2 -Cu 2 , Ni 2 -Cu 2 and of Cu , 2 -Zn 2 in toxicity than 1:1 synergies, the concentration ratio of 1:1 for the antagonism; the Hg 2 -Zn 2 Hg 2 -Ni 2 -Zn 2 in toxicity than 1:1 and the concentration ratio of 1:1 when both antagonism; Ni 2 < / sup>-Cu 2 -Zn 2 in toxicity ratio of 1:1 for the first antagonistic added the concentration 1:1 antagonism; Hg 2 the-Cu 2 -Zn 2 for the first antagonistic coexistence sum; the Hg 2 -Ni -Cu 2 -Zn 2 to coexist in toxicity antagonism than 1:1, the concentration ratio of 1:1 for the first antagonistic sum. (4) from July 2006 to December set in the urban section of the Yellow River in Lanzhou five sampling points (bell home River Bridge, Silver Bridge Zhongshan Bridge, Yantan bridge, Paulhan Bridge) water samples were collected using the addicted hot Tetrahymena BF5 growth curve and generation time as indicators to evaluate water quality. The results showed that, five water samples of different degrees of inhibition on the growth of Tetrahymena generation time: 7.062h, 7.610h 7.686h 7.820h 8.038h obvious with the control 6.802h differences; α = 0.05 and α = 0.01 level, Duncan test, compare all sorts of points of difference; the last Euclidean distance - nearest neighbor method was clustering keel. Tetrahymena population growth curve and generation time change is reflected in the water pollution situation, differences and all sorts of point pollution, rapid assessment of water quality.

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