Struvite precitation improving subsequent culture of microalgae with ammonia-flocculation treatment

Struvite precipitation was used to study the highly efficient recovery of ammonia-nitrogen from the ammonia-flocculated medium of microalgae (Nannochlropsis oculata) and the improvement of the subsequent culture. The results showed that struvite precipitation could improved the recovery rate of ammonia-nitrogen obviously, the recovery rate reached 98.8%. Two mediums were most suitable for the growth of N. oculata. The biomass productivity, protein content and carotenoid content of N. oculata in Group N1 acquired 1.0, 2.1, 6.0 times as much as the control group, respectively. While the biomass productivity, protein content and carotenoid content of N.oculata in Group N5 acquired 1.4, 1.6, 4.7 times as much as the control group, respectively. The subsequent algal suspension could be harvested again through ammonia-flocculation. Moreover more than 90% of flocculating rate was reached in 10 minutes. Therefore,struvite precipitation can effectively improve the subsequent culture.