Monday, April 19, 2010
LL Conference Facility (Hilton Clearwater Beach)
Flocculation of microalgal biomass using natural polymeric materials could be a practical approach to achieve low cost harvest; however, flocculation of algal biomass is still poorly understood and the optimal conditions are generally unpredictable. In this study, the composition of the algal cell wall was investigated for its role in cell flocculation. Four strains of chlorella, which have different levels of amino sugars and uronic acids in their cell walls, were adjusted to a biomass concentration of ~0.3 g/L (non-ash free dry weight) and were flocculated with chitosan or pectin at dosage of 0 – 300mg/L at pH 5.5, 7 and 8.5. The four strains showed different flocculation patterns at different pH and concentrations of polymers. Flocculation improved for all strains at pH 8.5 suggesting other inter molecular forces such as hydrogen bonding might be more important than charge neutralization in the flocculation of chlorella.