Abstract The kinetics of Se uptake and toxicity to Lemna were studied over a period of 14 days of exposure to Se(IV) or Se(VI). The growth of Lemna stopped immediately after exposure to 5.0 mg/L of Se(IV) or Se(VI). The content of chlorophyll and phaeopigments of Lemna exposed to 5.0 mg/L of Se(IV) was two to three times less than in the control after 3 d exposure. Lemna took up Se rapidly within the first 3 d. The Se content in Lemna along with the exposure time fitted well the two-compartment and the hyperbolic model, which demonstrates that the mechanism of Se(IV) and Se(VI) uptake in Lemna is not only through passive diffusion, but also through other processes such as ion channel proteins or transporters. The kinetic bioconcentration factors (BCFs) were 231 and 42 for 0.5 mg/L Se(IV) and Se(VI) exposure, respectively. The uptake rate of Lemna reached 263 mg/kg/d and 28 mg/kg/d in the Se(IV) and Se(VI) treatments, respectively. This study showed that Se(IV) has a faster accumulation rate than Se(VI), but a higher toxicity, indicating Lemna could be a good candidate to remove Se(IV) from water, producing Se-enriched biomass which may eventually also be considered for use as Se-enriched feed supplement or fertilizer.

中文翻译：

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青萍中硒酸盐和亚硒酸盐的吸收、积累和毒性

摘要研究了暴露于 Se(IV) 或 Se(VI) 14 天期间的 Se 吸收动力学和对 Lemna 的毒性。暴露于 5.0 mg/L Se(IV) 或 Se(VI) 后，浮萍的生长立即停止。5.0 mg/L Se(IV)处理3 d后，浮萍的叶绿素和色素含量比对照减少了2～3倍。浮萍在前 3 天内迅速吸收 Se。浮萍中 Se 含量随暴露时间的变化均符合二室模型和双曲线模型，这表明浮萍中 Se(IV) 和 Se(VI) 的吸收机制不仅是通过被动扩散，还通过其他途径吸收。过程，例如离子通道蛋白或转运蛋白。0.5 mg/L Se(IV) 和 Se(VI) 暴露的动力学生物浓缩因子 (BCF) 分别为 231 和 42。Se(IV) 和 Se(VI) 处理中浮萍的吸收率分别达到 263 mg/kg/d 和 28 mg/kg/d。这项研究表明，Se(IV) 的积累速率比 Se(VI) 更快，但毒性更高，表明浮萍可能是从水中去除 Se(IV) 的良好候选者，产生富硒生物质，最终也可能用于考虑用作富硒饲料补充剂或肥料。