Chitosan modified attapulgite is used as the flocculant for precipitating

Chlorella vulgaris

with adding CaCl

2

as the coagulant. For

Chlorella vulgaris

the optimal flocculation conditions showed as following: flocculant is 0.4g/L

the ratio of chitosan and attapulgite in flocculant is 1∶12

CaCl

2

coagulant dosage is 0.2g/L

and pH of the solution is 9.0. Under the best conditions

the flocculation rate of

Chlorella vulgaris

can reach up to 95%. The scanning electron micrographs and the BET specific surface area data(BET) of flocculant show that the modified attapulgite adsorbs and connects with chitosan to a certain degree of spatial structure

which effectively increases the surface area of flocculant and is conducive to the adsorption of

Chlorella

.The raw materials used in this article could have the advantages of low cost

safety and low impact on the environment. And the high efficiency of flocculation can obtain with sample method of preparing the flocculant

which can be widely used for the harvest of microalgae in industrial production.