The results presented graphically in Figs. 2–4 show the growth curves of C. vulgaris obtained for each run of factorial
design. The results recorded in Table 3 represents the maximum specific growth rate (lmax) and Cmax of the 1st to 10th runs of the factorial design for evaluating the influence of the concentrations of both wastewater and sodium bicarbonate on the growth of the microalga C. vulgaris, as well as the reduction of colour and COD.