Strategic enhancement of algal biomass, nutrient uptake and lipid through statistical optimization of nutrient supplementation in coupling Scenedesmus obliquus-like microalgae cultivation and municipal wastewater treatment

Supplementing proper nutrients could be a strategy for enhancing algal biomass, nutrients uptake and lipid accumulation in the coupling system of biodiesel production and municipal wastewater treatment. However, there is scant information reporting systematic studies on screening and optimization of key supplemented components in the coupling system. The main factors were scientifically screened and optimized using statistical methods. Plackett–Burman design (PBD) was used to explore the roles of added nutrient factors, whereas response surface methodology (RSM) was employed for optimization. Based on the statistic analysis, the optimum added TP and FeCl3·6H2O concentrations for Scenedesmus obliquus-like microalgae growth, nutrients uptake and lipid accumulation were 4.41 mg L−1 and 6.48 mg L−1, respectively. The corresponding biomass, lipid content and TN/TP removal efficiency were 1.46 g L−1, 36.26% and >99%. The predicted value agreed well with the experimental value, as determined by validation experiments, which confirmed the availability and accuracy of the model.