谷氨酸棒杆菌等电点为4.2,当等电母液pH在3.2左右时,菌体zeta电势为正值,添加絮凝剂聚丙烯酸钠能有效使分散的细胞聚集成絮凝体。以菌体、COD及蛋白质去除率为指标,借助Mastersize 2000测定絮凝体粒度分布,考察了搅拌速率和搅拌时间对絮凝的影响。结果表明,在搅拌转速为400 r/min,搅拌时间为50 s时,絮凝效果最好,菌体、蛋白质、COD去除率分别达到99%、75%、55%以上,絮凝体粒径达到491μm,C.V.值为53.52%。搅拌速率和搅拌时间在很大程度上影响絮凝效果和絮凝体大小,控制搅拌速率和搅拌时间可以优化絮凝效果和优选絮凝体大小,增强絮凝后的沉降过滤。

The isoelectric point of Corynebacterium glutamicum was 4.2,and the dispersed cells could be effectively formed floc by adding the flocculant of sodium polyacrylate when the pH of isoelectric mother liquor was kept 3.2,where its bacterial zeta potential was positive.In order to study the impact of agitation rate and time on flocculation,the removal efficiency of bacteria,COD and soluble protein were taken as targets,and the size distribution of floc was then determined by using Mastersize 2000.The experimental results showed the best flocculation effect was obtained when the agitation rate and time were 400 r/min and 50 s,where the removal efficiency of bacteria,COD and soluble protein were above 99%,75%,55%,respectively.Meanwhile,the size of floc and the C.V.were above 491 μm and about 53.52%,respectively.The agitation rate and time played an important role on the influence of flocculation effect and size distribution.Therefore,in order to enhance the sedimentation and filtration after flocculation,the flocculation effect and floc size could be optimized by controlling the agitation rate and time.