产黄青霉废菌体对铅的吸附机理(Ⅱ)——铅生物吸附途径和吸附类型的确定

Mechanism of Lead(II) Biosorption by Waste Mycelium of Penicillium Chrysogenum—— Investigation of the pattern and type of lead biosorption

探讨了铅生物吸附途径和吸附类型。X射线衍射分析及离子竞争及洗脱实验结果表明 ,产黄青霉废菌体对Pb2 +的吸附途径有 2个 :第 1,Pb2 +与一些细胞自溶物或细胞碎片结合 ,沉积在吸附剂颗粒表面 ,这些沉积物具有晶体结构 ,此部分吸附量最大可占总吸附量的 5 3% ;第 2 ,Pb2 +与菌体表面结合位作用 ,进行离子交换吸附 ,Pb2 +与[H+/ 2 +Ca2 ++Mg2 +]等量置换 ,其中以离子键形式进行的吸附至少占离子交换吸附总量的 2 5 % ,其余主要为以共价 /配位键形式存在的化学吸附。

The pattern and type of lead biosorption by waste mycelium of Penicillium chrysogenum was studied. The X ray diffraction analysis and cation competition/desorption experiments indicated that the waste mycelium accumulated lead by two patterns: first, Pb 2+ combined with some cell's metabolites or autolysis matters, and deposited as crystalline structure on the surface of absorbent particles. The uptake of Pb 2+ by this way was approximately 53% of the total; second, Pb 2+ reacted with binding sites on cells by ion exchange.The amount of Pb 2+ adsorbed approximately equaled to the amount of [H +/2+Ca 2+ +Mg 2+ ] released, among which the ionic biosorption bond accounted 25%,and the others were covalent bond or complexation biosorption.