6种苯系物对球等鞭金藻和新月菱形藻的生长抑制

海洋环境中苯系物污染主要来源于海洋溢油事故以及沿海石油化工企业的废水排放。为探究苯系物对海洋微藻的毒性作用,选择球等鞭金藻和新月菱形藻作为受试生物,分别考察了苯、甲苯、乙基苯、邻-二甲苯、间-二甲苯和对-二甲苯6种苯系物对2种海洋微藻生长的影响。结果表明,在0.25~64.0 mg·L-1暴露浓度下,6种苯系物对2种微藻生长具有显著的抑制作用,随着暴露浓度的升高,抑制作用明显增强。苯、甲苯、乙基苯、邻-二甲苯、间-二甲苯、对-二甲苯对球等鞭金藻的24 h的半数效应浓度(24 h-EC50)分别为:17.07、12.88、7.58、0.55、0.36、0.27 mg·L-1;对新月菱形藻的24 h-EC50值分别为:1.03、0.68、0.46、0.40、0.42、0.38 mg·L-1。上述研究结果为确定苯系物海洋环境质量标准、保护海洋生态环境提供了基础数据。

Inhibitory Effect of Six Kinds of BTEXs on Growth of the Chrysophyceae Isochrysis galbana and the Diatom Nitzschia closterium

The marine pollution of benzene series (BTEXs), including benzene, toluene, ethyl benzene and xylene, is mainly from the marine oil spill and coastal petrochemical wastewater discharge. In order to reveal the toxic effect of BTEXs on marine microalgae, the chrysophyceae Isochrysis galbana and the diatom Nitzschia closterium were exposed to benzene, toluene, ethyl benzene, o-xylene, m-xylene and p-xylene, and the their growth rates were detected. The results showed that the growth of I. galbana and N. closterium were inhibited dramatically by the BTEXs at the exposed concentration from 0.25 to 64.0 mg·L^-1. The growth inhibition was enhanced with the concentration of BTEXs in well dose-effect manner. The 24 h-EC50 of benzene, toluene, ethyl benzene, o-xylene, m-xylene and p-xylene to I. galbana was 17.07, 12.88, 7.58, 0.55, 0.36 and 0.27 mg·L^-1. The 24 h-EC50 of the corresponding BTEXs to N. closterium was 1.03, 0.68, 0.46, 0.40, 0.42 and 0.38 mg·L^-1. The results presented in this study will provide basic data for establishing marine environmental quality criteria of BTEXs and protecting the marine ecological environment.