胞外生物高分子絮凝剂结构组成与絮凝机理研究  

Structure and flocculating mechanism of extracellular biopolymer flocculant BF SVI-SD

作　　者：张侠[1] 何玉凤[1] 潘素娟[1,2] 张玲[1] 刘世磊[1] 王荣民[1] 

机构地区：[1]生态环境相关高分子材料教育部重点实验室,甘肃省高分子材料重点实验室,西北师范大学化学化工学院,兰州730070 [2]天水师范学院生命科学与化学学院,甘肃天水741000

出　　处：《安全与环境学报》2010年第6期54-57,共4页Journal of Safety and Environment

基　　金：教育部新世纪优秀人才支持计划项目(NCET-06-0909);留学回国人员科研启动皋金项171(2007-1108)

摘　　要：通过研究胞外生物高分子絮凝剂(BF SVI-SD)的成分与结构,探讨了微生物絮凝剂的絮凝机理。首先采用双缩脲反应、茚三酮反应、蒽酮比色法、Molisch反应、紫外吸收光谱、红外吸收光谱和扫描电镜等方法研究了胞外生物高分子絮凝剂BF SVI-SD的成分与结构。发现絮凝剂BF SVI-SD的主要成分为多糖,结构中含有大量羟基和羧基。高分子链以聚集态形式存在,呈现较疏松的纤维状结构。同时,分析了微生物絮凝剂对淀粉废水和生活污水处理及毒性试验结果,提出了絮凝机理。由于该絮凝剂是一种极性大分子,与水中有机物颗粒之间存在范德华力,和质点之间以离子键、氢键形式结合,通过吸附架桥作用形成絮凝体。An extracellular biopolymeric flocculant （BF SVI-SD） with high flocculating activity was separated from a kind of microbial strains of SIV-4. Its major composition and structure have been studied in order to discuss the flocculation mechanism. Firstly, BF SVI- SD was characterized by the methods of biochemical reactions such as byninhydrin reaction, biuret reaction and anthrone colorimetfic analysis as well as Molisch reaction plus instrumental analyses which ineluding UV spectroscopy, IR spectroscopy and SEM imaging. The results show that BF SVI-SD is mainly consisted of polysaeeharide,which contains plenty of hydroxyl and carboxyl groups. The macromolecules of BF SVI-SI） aggregate when they are dried. The aggregates of BF SVI-SD show a loose fibrous structure. It has excellent flocculating properties in wastewater treatment such as starch wastewater and domestic sewage. In the treatment of domestic sewage, the removal efficiencies of COD and turbidity were 63.4% and 97.6% respectively. Meanwhile, in starch wastewater treatment, the removal efficiency of COD was 48.6%. It was also found that the BF SVI-SD was non-toxic. Its flocculation mechanism was proposed in the paper. Since it contains considerable amount of polar groups such as hydroxyl and carboxyl group, BF SVI-SD appears as a kind of polar macromolecule and tend to form hydrogen bonding with polysaccharide or peptides easily. Under the agitation, with the aid of Brownian movement and Van der Waals force, the biopotymers overcome the electrostatic attraction of suspended substances in wastewater. The biopolymeric flocculants could approach to the suspended granule pellets with hydrogen bonding, and form bridge association between the wadding substances. Then, the flocs formed rapidly indicating excellent flocculation activity of BF SVI-SD in wastewater treatment. The proposed mechanism was useful in the design and preparation of new synthetic polymeric flocculant which contains different functional groups, such as hydroxyl and carboxyl acid groups.

关 键 词：环境工程学 水处理 胞外生物高分子絮凝剂 絮凝机理 多糖 

分 类 号：X522[环境科学与工程—环境工程]