Advertisement

Journal of Applied Phycology

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

Flocculation of algae using chitosan

  • Ravi Divakaran
  • V.N. Sivasankara Pillai
Article

Abstract

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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Clasen J., Mischke U., Drikas M. and Chow C. 2000. An improved method for detecting electrophoretic mobility of algae during destabilization process of flocculation: flocculant demand of different species and the impact of DOC. Aqua 49: 89-101.Google Scholar
  2. Eaton A.D., Clesceri L.S. and Greenberg A.E. (eds) 1995. Standard Methods for the Examination of Water and Waste Water. American Public Health Association, Washington, DC, USA.Google Scholar
  3. Faust S.D. and Aly O.M. 1983. Chemistry of Water Treatment. Butterworths, 137-139, 699.Google Scholar
  4. Hejzlar J., Dolejs P., Komarkova J., Seda J., Simek K. and Vyhnalek V. 1998. Effect of biomanipulation on the structuring of the planktonic food web and water treatability by coagulation. Water Sci. Technol. 37: 105-112.Google Scholar
  5. Liu J.C., Chen Y.M. and Ju Y.H. 1999. Separation of algal cells from water by column flotation. Sep. Sci. Technol. 34: 2259-2272.Google Scholar
  6. Muzzarelli R.A.A. 1977. Chitin. Pergamon Press Ltd., Oxford, 247–253, 207-211.Google Scholar
  7. Nurdogan Y. and Oswald W.J. 1996. Tube settling of high-rate pond algae. Water Sci. Technol. 33: 229-241.Google Scholar
  8. Oufdou K., Mezrioui N., Oudra B. and Ouhdouch Y. 1998. Experimental study of the effect of Synechocystis sp. (picocyanobacteria) on the behaviour of some bacteria of sanitary interest. Annales de Limnologie - Int. J. Limnol. 34: 259-268.Google Scholar
  9. Pan J.R., Huang C.P., Chuang Y.C. and Wu C.C. 1999. Dewatering characteristics of algae-containing alum sludge. Colloids Surf., A 150: 185-190.Google Scholar
  10. Steynberg M.C., Adam K. and Pieterse A.J.H. 1998. An algal monitoring protocol: The strategic link between reservoir and treatment processes. Water Sci. Technol. 37: 153-159.Google Scholar
  11. Whitehead P.G., Howard A. and Arulmani C. 1997. Modeling algal growth and transport in rivers: a comparison of time series analysis, dynamic mass balance and neural network techniques. Hydrobiologia 349: 39-46.Google Scholar

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

Personalised recommendations