A 22 Central Composite Design (CCD) was used to study the
influence of the wastewater concentration and sodium bicarbonate
concentration on the C. vulgaris growth and the
removal of wastewater pollutants. The maximum wastewater
concentration for the Factorial Run Design was stipulated
from the preliminary cultivation tests of the microalgae in
the textile waste effluent, using as standard. Table 1 shows
the real and coded values of the variables used in the 22 Central
Composite Design (CCD). Distilled water was used for the
dilutions of the waste effluent.
Monitoring of algal growth
Data of the cell density using a haemocytometer slide versus
culture times were plotted and submitted to polynomial