The present study investigated the possible toxic effect of ZnO and CuO nanoparticles (NPs) on freshwater microalgae, Scenedesmus obliquus at environmentally- relevant nanoparticle concentration (1 mg/L) and high concentration (10 mg/L) in BG-11 medium under white light LED-illumination over 35 days. The effect of time on the stability of media, nanoparticles, and their relation to toxicity to algae was also studied. The transmission electron microscopy indicated structural damage to algae due to the presence of a mixture of nanoparticles (at 10 mg/L). FTIR (Fourier Transform infrared) analysis of a sample containing a mixture of nanoparticles showed an addition of bonds and a difference in the peak location and its intensity values. The inhibition time for biomass was observed between 14 days and 21 days at 10 mg/L NPs. At 1 mg/L, the order of toxicity of NPs to algae was found to be: CuO NPs (highest toxicity) > ZnO NPs>ZnO + CuO NPs (least toxicity). During exposure of algae cells to a mixture of NPs at 10 mg/L NP concentration, a smaller value of metal deposition was observed than that during exposure to individual NPs. Antagonistic toxic effects of two NPs on dry cell weight of algae was observed at both concentration levels. Future work is needed to understand the steps involved in toxicity due to mixture of NPs to algae so that environmental exposures of algae to NPs can be managed and minimized.

本研究调查了环境相关纳米颗粒浓度（1 mg/L）和高浓度（10 mg/L）下白光下 BG-11 培养基中 ZnO 和 CuO 纳米颗粒 (NPs) 对淡水微藻斜生栅藻的可能毒性作用LED 照明可持续 35 天。还研究了时间对介质、纳米粒子稳定性的影响及其与藻类毒性的关系。透射电子显微镜表明，由于纳米颗粒混合物（10 毫克/升）的存在，藻类结构受到损害。对含有纳米粒子混合物的样品进行 FTIR（傅里叶变换红外）分析显示键的添加以及峰位置及其强度值的差异。在 10 mg/L NP 下，观察到生物量的抑制时间为 14 天至 21 天。在1 mg/L时，纳米颗粒对藻类的毒性顺序为：CuO NPs（毒性最高）> ZnO NPs>ZnO + CuO NPs（毒性最小）。在将藻类细胞暴露于 10 mg/L NP 浓度的 NP 混合物中时，观察到的金属沉积值比暴露于单独的 NP 期间要小。在两种浓度水平下观察到两种纳米粒子对藻类干细胞重量的拮抗毒性作用。未来的工作需要了解纳米颗粒与藻类混合产生毒性的步骤，以便管理和最大程度地减少藻类对纳米颗粒的环境暴露。