Study On Biosorption Of Heavy Metals By The Living Algae

Currently, the problems of water environment, especially heavy metals pollution have been become a global environmental issue, which is also concerned to the entire community. Over the last decade, in the field of wastewater treatment, the researchers had done a lot of research that biosorption of heavy metals by non-liviny algae (algae powder), but the study of biosorption of heavy metals by living algae seldom reported.In this paper, study on biosorption of heavy metal by living-algae(Chlorella pyrenoidosa, Scenedesmus obliquus,Anabaena flos-aquae,Synechococcus elongatus, Microcystis aeruginosa), the first, study on algae growth and the effects of heavy metals on algae,then study the effects of biosorption of heavy metal by living algae, the final the kinetics for Cu²⁺ on Chlorella pyrenoidosa has discussed. The main research results are as follows:1) Study on algae growth and the effects of heavy metals on algae.In natural light and room temperature, study on growth and the effects of heavy metals on 5 kinds of algae.(1) 5 kinds of algae chlorophyll had two strongest absorption spectra of the absorption area: one is in the wavelength of 420 440 nm blue-violet light; another is the wavelength of 660 nm in the red part.(2) 5 kinds of algae growth is in line with the basic laws of the Logistic growth curve.(3) In different Cr⁶⁺ concentration, the tolerance of 5 kinds of algae: Microcystis aeruginosa>Anabaena flos-aquae >Synechococcus elongatus> Scenedesmus obliqu -us>Chlorella pyrenoidosa.2) Study on biosorption of heavy metal by living algae.In natural light and room temperature, study on the biosorption effects of Cu²⁺,Zn²⁺,Cr⁶⁺ on 5 kinds of living algae. (1) 5 kinds of algae in the concentration of heavy metals, R (the removal rate of Zn²⁺ on 5 kinds of algae ) first dropped and then rose, the last dropped; with the increasing concentration of Cu²⁺,the efficiency of absorption is different. with the increasing concentration of Zn²⁺, R (removal rate of Cu²⁺ on 5 kinds of algae) first rose rapidly, and then not much change, tend to balance; with the increasing concentration of Cr⁶⁺, R (the removal rate of Cr⁶⁺ on the 5 kinds of algae) decline.(2) In the Zn²⁺ concentration of 10.0 mg/L, R removal rate of Anabaena flos-aquae reached the maximum 59.20%;in the Cu²⁺ concentration of 3.0 mg/L, R removal rate of Scenedesmus obliquus reached the maximum 62.50%; in the Cr⁶⁺ concentration of 1.0 mg/L, R removal rate value of Anabaena flos-aquae was 32.87%.3)study on the kinetics for Cu²⁺ on Chlorella pyrenoidosaThe adsorption rate for Cu²⁺ on Chlorella pyrenoidosa was considerably high at the beginning of the adsorption, and the adsorption rate for Cu²⁺ was enhanced with the increasing temperature, the reaction order was 1, and the activation energy Ea =37.09 kJ/mol.