原子力显微镜观测絮凝剂与高岭土悬浮液的微观吸附形貌

分离到一种具有强絮凝特性的芽孢杆菌Bacillus sp.F2,并构建了絮凝基因组文库,从中筛选而获得表达絮凝活性的大肠杆菌阳性克隆子FC2,絮凝实验测定FC2的絮凝率为90%。采用云母片吸附的方式,较好地捕捉到了克隆菌FC2产生的絮凝体的微观结构,并采用轻敲模式下的原子力显微成像技术,对其吸附高岭土悬浮液形成的絮凝体的微观形貌进行了观测。与末加絮凝剂的高岭土悬浮液相比,加入FC2絮凝剂的高岭土悬浮液形成的絮凝体出现较大、紧密的球形颗粒结构,且表面粗糙,凹凸程度大,具有大的比表面积和吸附液体悬浮颗粒的能力。当向高岭土悬浮液中加入FC2絮凝剂后,絮凝颗粒由不定形且松散的结构转变为密集分布、水平尺寸均匀的球形结构,表明FC2絮凝剂中的凝集素容易使高岭土悬浮颗粒以絮凝体为吸附中心包裹在其表面,从更直观上进一步证实了FC2絮凝剂的除污效能,为研究生物絮凝剂的絮凝机理提供了有力的依据。

Observing the Micro-absorption Character of Flocculants and Kaolin Suspension by Atom-force Microscope

A strain of bacteria Bacillus sp.F2 with strong flocculability was separated,and the flocculants genome library was conceived. From the bacteria we obtain the coli form positive clone FC2 which shows flocculability.The flocculatation rate of FC2 is 90% through exper- iment.By adopting the mica flake to adsorb,we could get the micro structure of the flocculants produced by the clone bacteria FC2 easily. Then we use atom-force microscope technology under the mode of percussing to observe the character of the flocculated colloid.Compared with the kaolin suspension without the hquid ferment,the kaolin suspension with FC2 liquid ferment formed the flocculated colloid which is big and tight spherical structure and has well absorbability.This proved that the agglutinin in liquid ferment of FC2 can make the flocculants in the center then the kaolin suspension wrapt it up.This discovery offered a convincing proof for further study of flocculated mechanism.