Research On The Ability Of Natural Water Biofilms And Chlorella Biofilms To Adsorpt The Cd²⁺ By Fluorescence Labeling

In recent years, although heavy metal pollution has been reduced, but the heavy metal pollution in our country is still in a high level. Biofilms which are widespread in natural water solid material surface has a strong adsorption capacity of heavy metals. And, in the adsorption process, the amount of heavy metals contained in the natural water and biofilms are in a process of dynamic balance. Therefore, the content of heavy metals in biofilms partly reflects the situation of heavy metal pollution in water.In the past, the research of absorption characteristic in biofilms to heavy metal in nature water are built on the macro quantitative method. The research in more micro cosmic rarely reported. This paper use the Cd Te nanocrystals labeling the biofilms, explored a new method, fluorescence labeling, to analysis the adsorption capacity of Cd²⁺ in the wet state, and not destroy the natural water biofilm morphology and the Cd²⁺ absorbed in the biofilms. And taking Chlorella as an example, analysis of the adsorption capacity of Cd²⁺.The results showed that using hydrothermal method can synthesize the Cd Te fluorescent nanocrystals which have the characteristics that when Cd Te combined with Cd²⁺, the emission wavelength would shift to red. Using this characteristics label the biofilm which already adsorbed Cd²⁺to analysis of the adsorption capacity of Cd²⁺ is achievable. Separate the Chlorella analysis the adsorption capacity of Cd²⁺. The result shows that found that the concentration of Cd²⁺is 241.2±33.3μM in Chlorella cell membrane. The concentration of Cd²⁺ was 231.2±32.1μM in Chlorella cell inside. The concentration of Cd²⁺ in Chlorella cell membrane is slightly larger than the concentration of Cd²⁺ in the cell inside. But in generally, they had no significant difference between the two area, Cd²⁺ in Chlorella cells was uniformly distributed.