风化煤固定化微生物细胞制备及其固定化机制

Preparation and immobilization mechanism of weathered coal-immobilized microbial cells

以改性风化煤为载体,采用吸附固定化法制备固定化微生物细胞,通过PBD(Plackett-Burman)与PBB(Box-Behnken)相结合的方法优化其固定化工艺,实现其钝化铅污染水体能力的最大化,并结合多种表征技术明确微生物与载体的结合特征.结果表明,接菌比、固定化温度和固定化pH值是风化煤固定化微生物过程的关键因素;当接菌比为7、固定化温度31℃、固定化pH=6.5,固定化微生物细胞的单位Pb^(2+)吸附量和去除率可达到313.83mg/g和80.42%,较游离微生物提高了3.8倍,与国内外同类材料相比处于较高的水平;该固定化微生物细胞主要通过表面吸附、孔隙填充、静电引力以及共价键(−OH、−NH_(2)、−CONH_(2)、−COOR)等作用实现固定化.本研究可为风化煤载体制备固定化微生物细胞提供理论支撑.

In this study,the modified weathered coal was used as the carrier to prepare for immobilized microbial cells by adsorption immobilization method.PBD(Plackett-Burman)and PBB(Box-Behnken)were used to optimize the immobilization process of microbial cells,so that the ability of this cells was maximized to passivate lead polluted water.A variety of characterization techniques were used to study the binding characteristics of microbial cells and carriers.These results showed that the quantity of microbial cells,immobilized temperature and pH were the key factors.When inoculation quantity was 7,the immobilized temperature was 31℃,and pH was 6.5,the unit Pb^(2+)adsorption capacity and removal rate of immobilized microbial cells could reach 313.83mg/g and 80.42%,which were 3.8times higher than free microbial cells.Compared with similar materials at home and abroad,it has a high level.Surface adsorption,pore filling,electrostatic attraction and covalent bonds(-OH,-NH_(2),-CONH_(2),-COOR)promote the immobilization of microorganisms on weathered coal jointly.This study can provide theoretical support for the preparation of immobilized microbial cells by weathered coal carriers.