Zhu Xin, Zhang Jian-hua, Zhang Hong-jian, Mao Zhong-gui, Yang Yu-ling
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.
