Abstract—

The toxicity of chemical substances depends not only on their concentration but also on the hydrochemical composition of water (concentration of calcium and magnesium, humic substances, etc.), which is important to consider when extrapolating the results of bioassay to environmental conditions. A study into the acute toxicity of aluminum chloride was carried out on 1-day-old Daphnia magna crustaceans using natural and artificial water with different hardness parameters. Both artificial and natural water showed a decrease in the toxicity of aluminum ions with increasing the hardness; however, the range of changes in the toxicity in artificial water turned out to be much smaller than in natural water. Thus, in artificial water, an increase in the hardness from 0.021 to 6.46 °e led to an increase in the value of the 48-h half-lethal aluminum concentration by 1.57 times, while a similar range of changes in the hardness in natural water (0.21–8.53 °e) led to a change in this indicator by almost six times. Such differences may be associated with the influence of other hydrochemical factors typical for the studied water types. Thus, when conducting bioassay for the purpose of environmental regulation, artificial water cannot serve as a fully adequate replacement for natural water, the chemical composition of which is characterized by spatial heterogeneity.

中文翻译：

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铝离子对水蚤的毒性取决于天然水和人工水的硬度

摘要-

化学物质的毒性不仅取决于其浓度，还取决于水的水化学成分（钙和镁，腐殖质等的浓度），在将生物测定结果外推至环境条件时，必须考虑这一点。对1天大水蚤（Daphnia magna）氯化铝的急性毒性进行了研究甲壳动物使用具有不同硬度参数的天然和人造水。人造水和天然水都显示出铝离子的毒性随着硬度的增加而降低；然而，事实证明，人造水中毒性的变化范围比天然水中小得多。因此，在人造水中，硬度从0.021增加到6.46°e，导致48小时半致死铝浓度的值增加了1.57倍，而天然水中硬度的变化范围相似（0.21-8.53°e）导致该指标变化了近六倍。这种差异可能与受研究水类型典型的其他水化学因素的影响有关。因此，在进行环境测定目的的生物测定时，