紫外光辐射鱼腥藻产生羟基自由基的特性

Production characteristic of hydroxyl radicals induced by Anabaena cylindrica with UV irradiation

为了清晰藻类光化学生态修复受污染水体中活性氧的作用机制,研究了低紫外辐射强度下鱼腥藻产生羟基自由基(·OH)的特性,并系统分析了关键因素的影响.结果表明,紫外光辐射鱼腥藻可产生大量的·OH,暗处和自然光条件下短时间内·OH产生量近似为零.鱼腥藻数量增加,可提升·OH产生量,过高藻浓度可导致光穿透性变差.鱼腥藻水溶液酸性较强或呈碱性时,不利于·OH的产生,较适宜p H值为6—7.低温不利于·OH的产生,且35℃时·OH产生量与25℃时·OH产生量相差较小.增加光照强度,可提升·OH的产生量.热预处理鱼腥藻不利于·OH的形成,但超声处理鱼腥藻可提高·OH产生量.

The production characteristics of hydroxyl radicals （ -OH ） induced by Anabaena cylindrica under low power UV lamp irradiation were investigated in order to clarify the photochemical mechanism of ecological restoration of contaminated water with ·OH generated by algae, and the effects of key factors on the production of ·OH were systematically discussed. The results indicated that large quantities of ·OH were produced in suspension of Anabaena cylindrica under UV irradiation. The amount of -OH approximated to zero under the dark or the natural light within short time. The amount of · OH was enhanced by increasing the concentration of Anabaena cylindrical, but too high concentration reduced the penetration of light. Moreover, strong acidic or alkaline aqueous solution of Anabaena cylindrical had a disadvantage to the production of · OH, and suitable pH values for · OH production in suspension of Anabaena cylindrica was between 6 and 7. Low temperature was found to be unfavorable for ·OH production, and there was little difference in the production of ＂OH between 25 ℃ and 35 ℃. Finally, the amount of ·OH increased with increasing irradiation intensity. Anabaena cylindrica treated with ultrasonic enhanced the production of · OH, whereas Anabaena cylindrica treated with heat reduced the production.