A voltammetric study on the adsorption of Cd(II) and Zn(II) on marine microalgae Tetraselmis gracilis (Kylin) butcher

Journal of the Brazilian Chemical Society

Kamila Dos Santos Maguerroski¹  Marilda Rigobello-masini¹  Jorge C. Masini¹ 

[1] ,Universidade de São Paulo Instituto de Química São Paulo SP ,Brazil

关键词: anodic stripping voltammetry;    biosorption;    dynamic speciation;    marine microalgae;   

DOI  :  10.5935/0103-5053.20130118

来源: SciELO

【 摘 要 】

Proton and metal binding capacities of living cells of the microalgae Tetraselmis gracilis were determined by potentiometric titration and anodic stripping voltammetry, respectively. Binding of Cd(II) and Zn(II) was studied in seawater (pH 8.2) by additions of either single metallic species or binary mixtures. Computation of metal concentrations considered the cell-metal aggregates as slow diffusing. Adsorption capacities and conditional equilibrium constants were 2.9 ± 0.3 µmol g-1 and 6.9 ± 0.3 L g-1 for Cd(II) and 18.5 ± 0.9 µmol g-1 and 8.8 ± 0.2 L g-1 for Zn(II), respectively. For titrations with binary mixtures of Cd(II) and Zn(II), the adsorption capacity of Cd(II) decreased to 0.14 ± 0.01 µmol g-1 and that for Zn(II) to 15.9 ± 1.1 µmol g-1. The results suggest that binding of Zn(II) inhibits that of Cd(II). Under conditions of depleted Zn(II), the alga surface binds Cd(II), a process that can lead to bioaccumulation.

【 授权许可】

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