【摘要】 为更好地认识微量有机污染物苯和砷联合暴露中蓝藻的生长及砷累积效应，探究了水环境中0.1 mg/L苯存在时铜绿微囊藻对砷酸盐（As（Ⅴ））的适应性以及藻体砷累积和对环境中有机物（TOC）及藻毒素（MCs）含量的影响.结果表明，0.1 mg/L苯存在时铜绿微囊藻对As（Ⅴ）的适应性.显著降低，主要表现为高浓度As（Ⅴ）（1 000.0 mg/L）显著降低藻体光密度(OD₆₈₀)与叶绿素a（Chl-a）及实际光合产率（Yield）.由OD₆₈₀、Chl-a、Yield得到0.1 mg/L苯环境下铜绿微囊藻对As（Ⅴ）的96 h半致死浓度(IC₅₀)表现为Chl-a<OD₆₈₀<Yield，且由Chl-a得到的96 h IC₅₀为2.23×10³mg/L，最大允许毒物浓度（MATC）为316.23 mg/L.Chl-a可做为敏感指标观测0.1 mg/L苯含砷水体中该藻的生长.微量苯（0.1 mg/L）存在时铜绿微囊藻通过增加TOC的释出来适应砷毒性，且显著降低该藻在1.0和1 000.0 mg/LAs（Ⅴ）浓度下MCs的释出含量.微量苯的存在可促进铜绿微囊藻胞内As的累积，并使1.0 mg/LAs（Ⅴ）作用下MCs的释出以及0.1和1.0 mg/L As（Ⅴ）作用下TOC的释出显著降低，而As（Ⅴ）的添加降低了0.1 mg/L苯环境下藻体TOC及MCs的含量.研究结果对深入了解实际水环境中微量有机苯与无机砷污染共存时的微藻砷去除及生态风险具有重要意义.更多还原

【Abstract】 In order to better understand the effects of trace organic benzene on algal growth and intracellular arsenic（As） accumulation in As polluted water,the adaptability of Microcystis aeruginosa （M.aeruginosa） to arsenate （As（Ⅴ））and the effects of As accumulation as well as total organic matters （TOC） and microcystins （MCs） contents in the pres‐ence of 0.1 mg/L benzene in water environment were investigated systematically.The results showed that the adapt‐ability of M.aeruginosa to As（Ⅴ） was significantly decreased when 0.1 mg/L benzene was presented,which was mainly reflected in the reduction of cell density (OD₆₈₀),chlorophyll a （Chl-a） and actual photosynthetic yield （Yield）at 1 000.0 mg/L As（Ⅴ） treatments.The 96 h As（Ⅴ） semi-lethal concentration (IC₅₀) of M.aeruginosa obtained from OD₆₈₀,Chl-a and Yield ranked in the order of Chl-a<OD₆₈₀<Yield with IC₅₀concentrations obtained from Chl-a of2.23×10³mg/L under 0.1 mg/L benzene conditions.The maximum allowable toxic concentration （MATC） of As（Ⅴ） was316.23 mg/L,and Chl-a was the better indicator to As（Ⅴ） stress compared with OD₆₈₀and Yield in 0.1 mg/L benzene.In the presence of 0.1 mg/L benzene M.aeruginosa adapted to arsenic toxicity by increasing TOC release,and significantly reduced MCs content at 1.0 and 1 000.0 mg/L As（Ⅴ） concentrations.The presence of trace benzene significantly enhanced the accumulation of As in M.aeruginosa.Meanwhile,the reduction of MCs release was detected obviously at1.0 mg/L As（Ⅴ） and TOC secretion in medium 0.1 and 1.0 mg/L As（Ⅴ）.As（Ⅴ） addition promoted TOC secretion but inhibited MCs release of M.aeruginosa in media under 0.1 mg/L benzene conditions.The obtained results are of potentially great significance for understanding As removal of algae and their ecological risks when organic benzene and As（Ⅴ） coexist in the actual water environment.更多还原