| Heavy metal is an important pollutant in the environment. Heavy metal, which enters into water, is mainly removed in particulate form. The translation of haavy matal on solid and liquid interface is controlled by both chemical processes such as adsorption,precipitation and diffluence,oxidation and reoxidize and biological processes such as plankton assimilate and release. The chemical effects have already been investigated abundantly. However some research suggest that biological effects are also remarkable. So the study to function mechanism of biology assimilation and release is especially required when the tranlation of heavy metal on the solid and liquid interface is discussed.Copper is an essential microelement for plankton, while it will exert toxicity effect at high concentrations. Therefore the speciation tranlation of heavy metal, especially nutrition heavy metal in the water environment and the chemical and biological effects to the speciation translation demand research thoroughly. In the experiment Microcystis aeruginosa and Scenedesmus obliquus were cultured in sterilized BG-11. Different volume of copper sulfate stock solution was added to the algae solution. Copper concentration ranged from 20～420μg/l. pH was adjusted to the desired value in the experiment (6.0,7.0,8.5 respectively). The cultures were incubated in an environment chambet illuminated at a lighe intensity of 500μE m-2 S-1 with 12/12h light /dark cycle at 25±1℃. The alga cell density was calculated by measuring the OD at 680nm every 24h through established algal density-OD680 working curve. Copper concentration was determined by atomic absorption spectrometry at the end of the experiment. Free copper concentraton was calculated by VISUAL MINTEQ software. In addition, kaolin was added to the aboved culture system. The growth of alga and distribution of different form of copper concentration in the culture was determined. FTIR and SEM were used to determine the property of kaoline. |
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