Effect of nitrogen and phosphorus removal by two species of Chlorella in allelochemical EMA condition

Abstract

In order to examine the effect of allelochemical EMA on the absorption of nitrogen and phosphorus by Chlorella vulgaris and Chlorella pyrenoidosa in eutrophic water, Algae were constantly cultured by BG-11 medium with different concentration of allelochemical. The experimental results showed that lower concentrations (0.1mg/L) of EMA have a growth-promoting effect on Chlorella. vulgaris, but no obvious effect with higher concentrations. However, EMA has a significant inhibitory effect on Chlorella. pyrenoidosa. EMA can also promote the absorption of ammonia nitrogen by two algae. After nine days experiment, The highest ammonia nitrogen removal efficiency occurred in the 1.1 mg/L concentration of EMA, Chlorella vulgaris and Chlorella Pyrenoidosa removal efficiency were 71.89% and 79.06% respectively. High concentration of EMA can inhibit the absorption and utilization of total nitrogen and total phosphorus by two algae. The best removal efficiency of TN were 45.44% (0.1mg/L EMA) and 58.80% (0.1mg/L EMA) respectively. The best removal efficiency of TP were 95.06% (0 mg/L EMA) and 99.70% (0.3mg/L EMA) respectively.