十六烷基三甲基氯化铵与荧蒽对小球藻的联合毒性及其作用机制

以普通小球藻(Chlorella vulgaris)为受试生物,采用批量培养方法研究了阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)与多环芳烃荧蒽(Flu)的联合毒性及其作用机制.结果表明,当CTAC初始浓度固定为100μg/L时,随Flu浓度的升高(0~100.84μg/L), CTAC与Flu的联合毒性由协同效应(0~22.50μg/L)转为拮抗效应(22.50~100.84μg/L).当Flu浓度为1.13μg/L时,协同效应达到最大(RI＝2.01),与对照组相比,生物量抑制率从37.5%增加至80.9%;对氮和铁单位吸收量分别从0.27mg和9.18μg降至0.09mg和2.14μg;藻细胞Zeta电位从-10.0mV提高至-8.3mV;叶绿素a和可溶性蛋白质含量分别从5.00mg/L和80.65μg/mg降为2.57mg/L和50.36μg/mg.根据实验结果分析, CTAC与Flu复合污染体系提高了藻细胞Zeta电位,抑制了小球藻对氮和铁的吸收,降低了藻细胞体内叶绿素和蛋白质的含量.

Joint toxicity and its mechanism of cetyltrimethyl ammonium chloride and fluoranthene on Chlorella vulgaris

Joint toxicity of cetyltrimethyl ammonium chloride (CTAC) together with fluoranthene (Flu) on Chlorella vulgaris was investigated by batch culture in laboratory. The joint toxicity of binary mixture of CTAC and Flu on Chlorella vulgaris changed from synergetic effect (0~22.50μg/L) to antagonetic effect (22.50~100.84μg/L) with increasing concentrations of Flu in the range of 0~100.84μg/L. The strongest synergetic effect (RI=2.01) was observed in the presence of 1.13μg/L Flu, and the percentage of inhibition of biomass increased from 37.5% to 80.9%, while the absorption of nitrogen and iron declined from 0.27mg to 0.083mg and from 9.18 μg to 2.14μg, respectively. At the same time, Zeta potential of algal cell increased from-10.0 mV to-8.3 mV, and chlorophyll-a and soluble protein content declined from 5.00mg/L to 2.57mg/L and from 80.65μg/mg to 50.36μg/mg, respectively. Above phenomena indicates that CTAC and Flu combined pollution system increased the Zeta potential of algal cell and thus inhibits the absorption of nitrogen and iron, which subsequently decreased the chlorophyll-a and protein content.