The Experimental Study On Killing Of The Typical Red Tide Algae With Hydroxyl Radical

Red tide has become a global marine disaster. Its frequent outbreak exacerbated marine pollution, influenced marine organisms, caused serious negative effects on worldwide marine ecological environment and marine resources utilization, even endangered the human health. How to control the marine red tide has become hot topics in the study of marine environment. However, literature research shows that there is no an effective and feasible method for killing marine red tide so far.In this paper, Karenia mikimotoi, Skelrtonema costatum and Alexandrium tamarense were studied. The formation of hydroxyl radicals by atmospheric pressure strong electric-field discharge was used as a core technology. We made full use of strong oxidizing, effective and environment friendly killing marine microorganisms, the characteristic advantage of hydroxyl radicals, to focus on studying the dose effect of killing three kinds of typical marine red tide algae by hydroxyl radicals. The sea water temperature, conductivity, salinity, pH, turbidity, DO, chemical oxygen demand (COD) and other parameters were measured to investigate the death mechanisms of red tide algae cells, in order to provide a new technology idea and method for people in using hydroxyl radicals to control and manage marine red tide.Experimental research shows that the hydroxyl amout for killing red tide algae raises with the increasing of the concentration of algae, different kinds of red tide algae have different response to the killing effect by hydroxyl radicals. When the initial concentration of three kinds of red tide algae is l×104cells/mL, Skelrtonema costatum can be reduced to the outbreak point of red tide as long as the TRO concentration reaches1.2mg/L. However,the Karenia mikimotoi and Alexandrium tamarense can not be reduced to the outbreak point of red tide until the TRO concentration reaches1.5mg/L and1.6mg/L. Karenia mikimotoi, after hydroxyl solution treatment, algal cell biological density gradually declines with the increase of time, the residual TRO in seawater has continuing killing effects for marine red tide algae. The results of sea water quality indicates that after killing by hydroxyl radicals, the aquatic environment won’t change, the water quality after treating satisfies the second type sea water quality standard. Hydroxyl radicals can decompose chlorophyll a, destroy the structural integrity of red tide algae cell membrane. It can decrease the activity of SOD enzyme, realize the lethal effect of red tide algae. The formation of hydroxyl radicals by atmospheric pressure strong electric-field discharge can effectively prevent and control the marine red tide, and has the long-term prospect of application.