酵母融合菌对铬离子的吸附特性研究

STUDY ON BIOSORPTION CHARACTER OF CHROMIUM BY THE YEAST FUSED STRAIN

酵母融合菌的完整细胞、细胞壁、细胞内含物富集水体中的铬,比较了各组分对铬离子的吸附能力差异,并进行了模型拟合.结果表明:细胞壁的去除率和吸附量都明显高于完整细胞;完整细胞及细胞壁对铬的吸附均符合Freundlich和Langmuir热力学方程,且细胞壁对Cr6+的最大吸附量和吸附亲和力都大于完整细胞,说明细胞壁是该吸附剂吸附重金属离子的主要部位.同时利用多种分析手段研究了各组分对铬的吸附行为:酵母细胞壁的特殊结构以及AFM图显示细胞壁可以为活性基团吸附、络合或螯合金属离子提供更为广阔的空间;X-射线衍射和FTIR分析检测表明吸附剂对铬的吸附并未破坏其本身的结构.

Chromium in wastewater was adsorbed by integrated cell, cell wall and inclusion of the yeast fused strain, respectively. The biosorption capability of different components was compared and the adsorption behavior was simulated using dynamic models. The experimental results showed that the removal ratio and the biosorption capacity of chromium by the cell wall were much higher than those by others. Both Freundlich and Langmuir thermodynamical equations were suitable for describing the biosorption of Cr^6＋ by the integrated cell and the cell wall. Furthermore, the maximum biosorption capacity and the affinity of the cell wall for Cr^6＋ all exceeded those of the integrated cell, which demonstrated that the cell wall was the main site for adsorbing metal ions. Several advanced analysis techniques were used to study the biosorption mechanism. The special structure of yeast cell wall and atomic force microscope experiment indicated that the cell wall could provide wider space for active radicles adsorbing and chelating metal ions. X-ray spectroscopy and Fourier transform infrared spectroscopy observations showed that structure of the biosorbent was not destroyed after biosorption.