海藻酸钙固定混合SRB菌群生物吸附Ni^2＋的动力学

利用海藻酸钙为载体包埋固定化硫酸盐还原菌(SRB)混合菌群,研究了固定化微生物吸附重金属镍离子的动力学特性.结果表明:固定化混合SRB菌群对Ni2 具有良好的吸附性能,最大吸附容量qm高达931.9mg(Ni2 )/g(SRB)颗粒,是一种颇具应用前景的生物吸附剂.固定化SRB吸附Ni2 的动力学过程可以用准二次动力学方程描述,整个吸附过程可以明显地分为两个阶段,即物理化学吸附阶段和生物沉淀阶段.扩散动力学研究表明,固定化颗粒的内扩散并非是唯一控制吸附速率的机制,整个吸附过程涉及到多种吸附机制.图4表3参14

Kinetics of Ni2+ Biosorption by Mixed SRB Population Immobilized in Ca-alginate

The mixed SRB population was acclimated and immobilized in Ca-alginate gel beads, and the immobilized SRB was used for removing Ni~ 2 from aqueous solution. The kinetic characteristics of Ni~ 2 biosorption by immobilized SRB were investigated. The experimental results demonstrated that the immobilized mixed SRB was effective in removing Ni~ 2 from aqueous solution, and the maximal absorption capacity was up to 931.9 mg/g dry beads (DW). This biomaterial should be a promising biosorbent for removing heavy metal ions form aqueous solution. The kinetics of Ni~ 2 biosorption onto the immobilized SRB followed pseudo-second order model and the biosorption process over the entire adsorption time range fell into two distinct stages, i.e., physiochemical sorption stage and bioprecipitation stage. Further study on diffusion kinetics showed that intra-particle diffusion was not the only rate-limiting step, there were several adsorptive mechanisms involved in the entire adsorption process. Fig 4, Tab 3, Ref 14