The comparison of three common microalgae for treating piggery wastewater

To better remove the nitrogen and phosphorus in piggery wastewater, more and more attention has been paid to microalgae-based process. The success of this process primarily depends on the involved microalgae, and thus screening suitable microalgae is very important. In this study, the potential of three microalgae species, including Chlorella vulgaris, Botryococcus braunii and Desmodesmus sp., was compared based on their growth rates, nutrients removal efficiency and the contents of valuable substances. Results showed that the biomass, the removal efficiency of NH 4 + -N and TP of Desmodesmus sp. CHXl were 0.88 g·L –1 , 78.5% and 91.7%, respectively, and the contents of chlorophyll, carotenoid, protein and lipid of Desmodesmus sp. CHXl were 8.89 mg·L –1 , 3.19 mg·L –1 , 0.51 g·L –1 and 0.095 g·L –1 , respectively, which were significantly higher than those of Chlorella vulgaris 1068 and Botryococcus braunii 765. Results indicated that the local specie of Desmodesmus sp. CHXl is advantageous for purification of piggery wastewater and also as nutritional resources, and it is more reliable to screen the involved microalgae from the local habitat.