Nutrients recycle and the growth of in synthetic wastewater under different sodium carbonate concentrations.

This study illustrated the growth of and recycle of nutrients in wastewater combined with inorganic carbon under autotrophic conditions. was cultivated under different conditions by adding sodium carbonate (NaCO) at 15-40 mg l separately in wastewater containing high nitrogen and phosphorus content. The growth characteristics of , pH and dissolved inorganic carbon (DIC) changes of microalgae liquid, the recycle rate of ammonia and phosphorus and lipid content were determined. The changes of pH and DIC showed that could use NaCO to grow, with lipid contents of 18-25%. Among all NaCO concentrations, 20 mg l was the optimum, of which had the highest NH-N recycle of 52% and recycle of 67%. By the 14th day, its biomass production also reaches the maximum of 0.21 g l. However, inorganic carbon fixation rate was inversely proportional to its concentration. Moreover, the biomass was in positive correlation with the NaCO concentration except 20 mg l, which provided a possibility that could be acclimatized to adjust to high concentrations of inorganic carbon to promote biomass accumulation and recycle of nutrients.