Summary: | 碩士 === 國立成功大學 === 環境工程學系碩博士班 === 101 === Daphnia magna has been used as a useful test species and its sensitivity to environmental pollutants has been recognized as a general representative of other freshwater zooplankton species. The aims of this study were using Daphnia magna to assess the acute toxicity of chemicals compounds and effluents for 48 h exposure to check the impact of effluents on the toxicity of the receiving water body to assure the compliance of toxicological emission limits. 48 h LC50 of inorganic chemical compounds were determined and rank order of toxicity as follows:
CuSO4.7H2O〉ZnSO4.7H2O〉NiCl2.6H2O〉CoCl2.6H2O〉Al2(SO4)3〉MnSO4.4H2O〉FeSO4.7H2O〉MgSO4.7H2O〉NaCl〉Na2SO4. Chemical analysis with ICP/MS was conducted to determine the toxicity of metals in chemical compounds. The 48 h LC50
values in ppm of metals were: 1.15 for Ni, 3.8 for Co, 7.2 for Mn and 80 for Mg. The order of toxicity of metals in this study was: Cu〉Ni〉Co〉Mn〉Fe〉Mg〉Na. The toxicity of phosphate and ammonia also was tested. LC50 of phosphate was 95 mg.L-1 as PO43-. The ammonia toxicity was assessed at two different pH’s 6.5 and 7. The result showed that acute toxicity effect for Daphnia magna of total ammonia increases with increasing pH with LC50 at pH 6.5 and 7 was 155 and 19.5 mg.L-1 as NH4Cl, respectively. In this study, nine effluents were assessed for their toxicity and toxicity
levels. Toxicity of effluents was different based on acute toxic unit. Concentrations of metals in these effluents were measured. It was determined that concentrations of
heavy metals of effluents were very low. Na and K were found to be the major metals causing toxic effects of effluents because of high concentrations. Besides that,
phosphate was another component that affect to the toxic of effluents.
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