Abstract

Despite all advantages of nanoparticles and their widespread utilization, the potential contamination caused by nanoparticles should be considered. They may enter aquatic media and cause the environmental concerns and adverse effects on living organisms, especially the aquatic animals. Iron oxide and cobalt oxide NPs are among the most widely used metal nanoparticles by the useful properties in wastewater treatment, biomedicine, sensors. There is the possibility to enter the environment and cause toxicity and interaction with ecosystem organisms. This study investigates the acute toxicity of iron oxide and cobalt oxide NPs on Daphnia magna which is the source of food chain after phytoplankton in aquatic ecosystems and the biological indicator in bioassay tests. Using OECD method (202), the different concentrations of Fe₂O₃ and Co₂O₃ nanoparticles were exposed to D. magna in the periods of 24, 48, 72, and 96 h at the temperature of 20–24°C. LC₅₀ of iron oxide and cobalt oxide NPs were analyzed by Probit method for the determination of D. magna proportion in each solution following 96 h and respectively the following amounts of 163.21 and 121.04 mg L^–1 were observed, affected by concentration and time (p < 0.05). According to aquatic hazard classification of USEPA, nanoparticles with LC₅₀ value above 100 mg L^–1 have lower acute toxicity for aquatic animals. Still, they may have a more negative impact on ecosystems and aquatic organisms in long run. However, they were less toxic than other nanoparticles, but with a certain trend in different environments and combined with other substances. The results of the study showed the lower rate of toxic effect in nano-iron oxide compared to nano-cobalt oxide in D. magna. Finally, proposed two new values for SAR and SAFE Coefficients.

中文翻译：

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纳米颗粒 Co2O3 和 Fe2O3 对淡水中大型水蚤的生态毒性

摘要

尽管纳米颗粒具有所有优点及其广泛应用，但仍应考虑由纳米颗粒引起的潜在污染。它们可能进入水生介质，对生物体，尤其是水生动物造成环境问题和不利影响。由于在废水处理、生物医学、传感器中的有用特性，氧化铁和氧化钴纳米颗粒是最广泛使用的金属纳米颗粒之一。有可能进入环境并引起毒性并与生态系统生物相互作用。本研究调查氧化铁和氧化钴 NPs 对大型蚤的急性毒性是水生生态系统中仅次于浮游植物的食物链来源，是生物测定试验中的生物指标。使用 OECD 方法 (202)，在 20–24°C 的温度下，不同浓度的 Fe ₂ O ₃和 Co ₂ O ₃纳米颗粒在 24、48、72 和 96 小时内暴露于D. magna 。用 Probit 法分析氧化铁和氧化钴 NPs 的LC _{50以测定 96 h 后每种溶液中的}D. magna比例，分别观察到以下量为 163.21 和 121.04 mg L ^-1，受浓度和时间的影响（p< 0.05)。根据美国环保署水生危害分类，LC ₅₀值高于100 mg L ^-1的纳米粒子对水生动物的急性毒性较低。尽管如此，从长远来看，它们可能对生态系统和水生生物产生更负面的影响。然而，它们的毒性比其他纳米粒子小，但在不同环境中和与其他物质结合时具有一定的趋势。研究结果表明，与D. magna中的纳米氧化钴相比，纳米氧化铁的毒性作用率较低。最后，提出了 SAR 和 SAFE 系数的两个新值。