Study on Characteristics of Microbial Flocculant Produced by E.coli Strain

Flocculation characteristics of bioflocculant produced by E.coli were studied.It showed that the flocculants produced by E.coli mainly exist in the supernatant and they were synthesized during the cell growth,but the production time of microbial-flocculants tends to lag behind.High flocculation efficiency could be achieved when the pH values were kept in between 5.0～8.0,the concentration of kaolin clay suspension was 2～4 g/L.Metal cation such as Ca~(2+),Mg~(2+) facilitates flocculation efficiency of microbial-flocculants,and the available range of Ca~(2+) is 0.2～0.5 g/L.The results of flocculation test show that the E-9 can produce a strong-activity flocculants,which has higher flocculating effect compared with other MBF and ordinary flocculants against kaolin clay suspension.