Journal of Applied Phycology

, Volume 14, Issue 5, pp 419–422 | Cite as

Flocculation of algae using chitosan

  • Ravi Divakaran
  • V.N. Sivasankara Pillai


Flocculation of three freshwater algae, Spirulina,Oscillatoria and Chlorella, and onebrackish alga, Synechocystis, using chitosan was studiedinthe pH range 4 to 9, and chlorophyll-a concentrations inthe range 80 to 800 mg m−3, which produces aturbidity of 10 to 100 nephelometric turbidity units (NTU) in water. Chitosanreduced the algal content effectively by flocculation and settling. Theflocculation efficiency is very sensitive to pH, and reached a maximum at pH7.0for the freshwater species, but lower for the marine species. The optimalchitosan concentration that is required to effect maximum flocculation dependedon the concentration of alga. Flocculation and settling were faster whenconcentrations of chitosan higher than optimal are used. The settled algalcellsare intact and live, but will not be redispersed by mechanical agitation. Thede-algated water may be reused to produce fresh cultures of algae.

Alga Chitosan Chlorella Coagulation Flocculation Natural turbidity Oscillatoria Spirulina Synechocystis 


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Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Ravi Divakaran
    • 1
  • V.N. Sivasankara Pillai
    • 1
  1. 1.School of Environmental StudiesCochin University of Science and TechnologyErnakulamIndia

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