A Comparative Study of <i>Scenedesmus dimorphus</i> Cultured with Synthetic and Actual Wastewater

This study compared the growth of the microalgae Scenedesmus dimorphus in synthetic wastewater and actual wastewater under different cultivation conditions, in terms of nitrogen and phosphorus availability, wastewater quality, light condition and CO2 addition. The results show that the form of nitrogen source had a significant effect on the growth of microalgae. Urea as a nitrogen source increased the growth rate of S. dimorphus significantly, while the high concentration of inorganic nitrogen inhibited the growth. When phosphate was 4 mg/L and pH was 7, the growth of S. dimorphus was the greatest. The bacteria in actual wastewater not only promote the growth of microalgae but also facilitate the formation of flocs, which is conducive to biomass harvest. With the increase in light intensity and light duration, S. dimorphus showed primarily an increasing and then a decreasing trend. Higher light intensity was required in actual wastewater than in synthetic wastewater, which may be due to the barrier effect of wastewater turbidity. S. dimorphus grew well in both kinds of wastewater with the addition of 2% CO2