【摘要】 紫外/过氧化氢（UV/H₂O₂）处理技术可对环境中常见的有机污染物苯进行高效降解.为进一步认识该技术在处理苯污染前后可能产生的水生态环境效应，以对极端环境具有较好适应性的铜绿微囊藻为实验藻种，分别探讨处理苯污染前后对该藻的生长影响及毒性效应.结果表明：降解前的苯溶液因有H₂O₂的存在对藻体的细胞密度(OD₆₈₀)、叶绿素a（Chla）和实际光能转化率（Yield）抑制明显，不同时间下由其得到的苯的半抑制浓度(IC₅₀)表现出较强的急性毒性效应，且以OD₆₈₀最为敏感；降解后的溶液对藻体的生长抑制效应显著降低，不同时间下得到的苯的IC₅₀是降解前的105倍，显示出慢性毒性效应，以Chla更为敏感.降解前后介质中的UV₂₅₄可以很好地响应藻体的生长及藻毒素（MCs）的释放.降解前后均表现出随水环境中苯浓度的增高对藻体生长及MCs释出的显著抑制效应.研究结果有助于对UV/H₂O₂技术处理苯污染可能导致的水生态环境效应的全面了解.更多还原

【Abstract】 Ultraviolet/hydrogen peroxide （UV/H₂O₂） treatment technology can efficiently degrade benzene, a common organic pollutant in aquatic environment. In order to further understand the potential aquatic ecological effects before and after treating benzene by UV/H₂O₂process, Microcystis aeruginosa was used as the experimental algal species,which has good adaptability to extreme environments, to investigate the effects of algal growth and benzene toxicity before and after treating by UV/H₂O₂respectively. The results showed that the presence of H₂O₂in the benzene solution before degradation significantly inhibited the algal cell density (OD₆₈₀), chlorophyll a （Chla） and the actual photosynthetic efficiency （Yield） of M. aeruginosa. Meanwhile, the half maximal inhibitory concentration (IC₅₀) of benzene obtained from different culture time exhibited severe acute toxicity effects with OD₆₈₀as the most sensitive indicator before degradation. The inhibitory effects of benzene on algal growth significantly reduced after UV/H₂O₂degradation, and the IC₅₀obtained from different culture time was 10⁵times higher than before degradation,which showed chronic toxicity effects with Chla as the most sensitive indicator. The UV₂₅₄in media could reflect algal growth and microcystins （MCs） release well before and after degradation. The significant inhibitory effects on algal growth and MCs release with benzene concentrations increasing in media were observed for both before and after UV/H₂O₂degradation. The results were helpful for the comprehensive understanding of possible aquatic ecological effects caused by UV/H₂O₂process applying in benzene treatments.更多还原