Comparison Study on Growth, Removal of Nitrogen and Phosphorus, and Nutritional Property of Two Species of Microalgae

In order to screen the microalgae species for purifying aquaculture wastewater effectively and producing biomass with high nutritional value, two species of microalgae lately isolated from aquaculture wastewater were studied concerning theirs growth, removal efficiencies of nitrogen and phosphorus, and nutritional property. Results showed that the maximum biomass (dry weight) of Scenedesmus and Selenastrum were 0.78g•L-1 and 0.53g•L-1, respectively; their maximum biomass (dry weight) growth rate were 0.05g•(L•d)-1 and 0.03g•(L•d)-1, respectively. In 23 days, the removal efficiencies of TN by Scenedesmus and Selenastrum were 85.1% and 72.5%, respectively; TP could be efficiently removed by 82.6% and 79.7%, respectively. At the stable phase, the crude protein content and crude protein production (dry weight) of Scenedesmus, Selenastrum were 31.8%, 19.2% and 0.24g•L-1, 0.09g•L-1, respectively; the crude lipid content and crude lipid production (dry weight) of them were 7.81%, 9.26% and 0.06g•L-1, 0.05g•L-1, respectively. In general, Scenedesmus has obvious advantages over Selenastrum in the respects of growth, removal of nitrogen and phosphorus and nutritional value, and it can be used as the preferred algal species for follow-up study.