[Inhibition and elimination of chlorine dioxide on Phaeocystis globosa]

Different densities of red tide organism, Phaeocystis globosa (ST strain) were exposed to different concentrations of chlorine dioxide. The results showed that chlorine dioxide could effectively kill and control the algae. When the algae, in the density of 2.35 x 10(9) cells.L-1, was exposured to ClO2 above 0.74 x 10(-2) mmol.L-1, it was inhibited, and eliminated under ClO2 concentration above 2.96 x 10(-2) mmol.L-1. When the density of algae was 2.35 x 10(9), 1.18 x 10(9), 4.70 x 10(8) and 1.18 x 10(8) cells.L-1, the concentration of chlorine dioxide which could kill the algae efficiently in 96 h was 2.96 x 10-2, 2.22 x 10-2, 1.48 x 10-2 and 0.59 x 10-2 mmol.L-1, respectively. Under the same rate of inhibition or elimination, the higher the density of algae was, the lower the concentration of chlorine dioxide was to effectively control the growth of algae cell, ClO2 could be considered as a potential algaecide to control red tide.