on filtered water, initial pH brought up
to 7. Inoculum for experiments was cultivated in 250 ml
Erlenmeyer flasks and then in 1000 ml and finally in 5000 ml
flasks. The stirring was provided by the atmospheric air bubbling
(250 ml/min). The growth condition were kept constant under controlled
temperature (24 ± 1 C), with light intensity at 3000 lux at
all times during the process. The culture (20 106 cells/ml concentration)
was harvested in the end of log phase and then used for
testing flocculation efficiency.