Effect of Phosphorus Concentration on the Coupling Between Sludge Digestate Treatment and Microalgae Cultivation

Compared with the traditional wastewater treatment methods, microalgae treatment technology has several advantages, such as a more expansive treatment range and lower cost. This study showed that the growth of Chlorella pyrenoidosa, the output of oil and grease at different phosphorus concentrations, and the ability to treat wastewater, and controlled the phosphorus concentration in water by phosphate injection to investigate the effectiveness of wastewater treatment with Chlorella. The results of the study showed that the growth of Chlorella was approximately the same when the control dosing concentrations were 0 mg/L, 10 mg/L, 25 mg/L and 50 mg/L. The highest cell concentration days were all around the highest cell concentration days were all around the sixth day, and the growth of Chlorella was better as the phosphorus concentration kept. The treatment trend of each index of the wastewater was basically the same, and the maximum removal rate of TN was 81.18, 83.53, 87.47 and 88.49%, and the maximum removal rate of TP was 90.19, 95.40, 94.43 and 96.17%, respectively. The maximum total lipid rate of Chlorella was reached at the phosphorus injection concentration of 10 mg/L.