沉淀酵母菌对Pb(Ⅱ)的吸附机理研究

On the mechanism of Pb(Ⅱ) biosorption by deposited saccharomyces cerevisiae

应用红外光谱(FTIR)和X射线光电子能谱(XPS)等研究了沉淀酵母菌对Pb(Ⅱ)的吸附机理。从扫描电镜图片可以看出,吸附Pb(Ⅱ)后沉淀酵母菌细胞发生变形,细胞之间相互粘连;能量分析谱证实Pb(Ⅱ)与细胞表面的K进行了交换吸附;比较吸附Pb(Ⅱ)前后沉淀酵母菌的红外光谱可以发现,糖醛酸COOH基团C—O伸缩振动蓝移了13.59 cm-1,C=O伸缩振动红移了5.42 cm-1,N—H伸缩振动峰红移了4 cm-1,C—O伸缩振动蓝移了2.86 cm-1,说明了COOH、C=O、C—O、N—H为沉淀酵母菌吸附Pb(Ⅱ)的主要活性基团。X射线光电子能谱进一步证实了吸附后Pb(Ⅱ)主要同N、O、P等元素形成配合物。沉淀酵母菌对Pb(Ⅱ)的吸附是离子交换和表面络合共同作用的结果。

The paper is aimed at presenting the authors＇ research on the meehanism of Pb （ Ⅱ ） hiosorption by the deposited saccharomyces serevisiae with FTIR and XPS as its chief analytical means. The SEM results indicate that the deposited saccharomyces cerevisiae cells have changed their form after the adsorption. Meanwhile, the speetrum energy analysis helps to substantiate the interactive adsorption between Pb and K on the cell surfaces. At the same time, the FTIR analysis of the deposited substances before and ＇after adsorption reveal that COOH, C -- O, C--O, N--H are the main adsorption positions in the process of deposited adsorption in the carboxyl groups in which C--O stretching vibration blue may have shifted 13.59 cm^-1, with C = O stretching vibration red shifting 5.42 cm^-1 N--H stretching vibration red-4 cm^-1 and C--O vibration blue-2.86 cm^ -1. XPS has also validated that Pb mainly exists in the form of its oxidc after adsorption. Therefore, the adsorption of deposited saccharomyces cerevisiae adsorption on Pb（ H ） has mainly resulted from both the ion exchange and the surface chelation.