Effect of different concentrations of bleaching powder treatments on water Chlorella vulgaris and protozoa

In this experiment, using Chlorella vulgaris as the research object, we take advantage of the stronger antioxidant ability in Chlorella vulgaris than that in protozoa, adding 7 group of bleaching powder concentrations into algae which were polluted by protozoa, and study the optimum bleaching powder concentration. The results were listed below: under 25℃, 2 500 lx light and the salinity of 26 conditions, concentration of 15 mg/L bleaching powder was the most beneficial to the growth of Chlorella vulgaris.It could effectively kill the protozoa in algae liquor, algae cell could recover in 1~2 days, and it failed to observe the protozoa under microscopic examination. At the concentration of 15 mg/L，Chlorella vulgaris breeded rapidly, growed best, and could reach the conventionally cultured of algal cells density.