六价铬抑制淡水蓝绿藻生长的毒性效应

采用化学品毒性藻类测试的标准方法得到Cr(Ⅵ)抑制蛋白核小球藻、聚球藻、极大螺旋藻、钝顶螺旋藻、羊角月牙藻和四尾栅藻生长的96h-EC₅₀分别为4.96、6.50、11.16、11.74、12.43、20.89mg/L;6种蓝绿藻对Cr(Ⅵ)耐受性大小顺序为:四尾栅藻＞羊角月牙藻＞钝顶螺旋藻＞极大螺旋藻＞聚球藻＞蛋白核小球藻.不同藻类对Cr(Ⅵ)的敏感程度可能与细胞大小和形状、细胞壁结构、藻类分泌物以及酶的作用有关.本文运用X射线吸收近边结构(XANES)初步研究了蛋白核小球藻对Cr(Ⅵ)的吸收和转化.

Toxic Effects of Hexavalent Chromium on the Growth of Blue-Green Microalgae

A standard method of algal bioassay for determining the toxicity of toxic chemicals was applied to the interaction between Cr(VI) and six blue-green microalgae. The 96h-EC50 of hexavalent chromium on the growth of Chlorella pyrenoidosa, Synechococcus, Spirulina maxima, Spirulina platensis, Selenastrum capriornutum and Scenedesmus quadricauda were 4.96, 6.50, 11.16, 11.74, 12.43 and 20.89 mg/L, respectively. The tolerance of the six blue-green microalgae to Cr(VI) was in the order of Scenedesmus quadricauda > Selenastrum capriornutum > Spirulina platensis > Spirulina maxima > Synechococcus > Chlorella pyrenoidosa. The sensitivity of these species to Cr(VI) might relate to the cell size, the structure of cell wall, as well as the redox reaction caused by the exudate or enzyme. X-ray absorption near edge structure(XANES) was used to study the accumulation and transformation of Cr(VI) in Chlorella pyrenoidosa.