Abstract: A new recycling mode to culture green algaChlorellavulgariswas designed to solve the difficulties in harvesting and recycling of the supernatant. The concrete procedures included the alga culture with air-lift reactor, flocculate by addition of chitosan, collection of the supernatant through filtration, addition of nutrients into supernatant, and putting supernatant into air-lift reactor to culture further.The result showed that there were slightly higher growth rate and harvest levels of the algae in the next four cycles compared to the first cycle of the alga culture. The flocculation of chitosan was found to be effective, without inhibition. The supernatant supplemented with quantitative nutrients, nutrients representative NO-3-N, PO3-4-P content were accumulated in the absence of inhibition within each cycle. In conclusion, the effect of chitosan flocculation and the recycling supernatant harvested for the alga culture is quite acceptable.
2012, Vol. 27 
