School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China; Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Henan Province, China.
School of Materials and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, China.
Chemosphere. 2023 Oct;337:139313. doi: 10.1016/j.chemosphere.2023.139313. Epub 2023 Jun 22.
The potential impacts of metallic nanoparticles (NPs) at environmental levels on freshwater ecosystems cannot be ignored due to their frequent release. The most widely used metallic oxide, ZnO NPs and TiO NPs (100 ng L) were applied to explore their single and combined effects on leaf litter decomposition. Although ZnO NPs and TiO NPs alone or in combination increased 22.68%-41.17% of the leaf decomposition rate, they performed different toxic mechanisms in ecological processes. The microbial mass and enzyme activities significantly increased after acute exposure, but significantly decreased after chronic exposure to ZnO NPs. The activity of BG was the most sensitive factor that was decreased by 66.22%, 56.97%, and 39.39% after 21-day exposure to ZnO NPs, TiO NPs, and in combination, respectively. In addition, the analysis of Fourier transform infrared spectroscopy suggested a novel perspective on understanding the promoting mechanism. The promotion effect of ZnO NPs relied on the enhanced decomposition of refractory organics and easily degradable substances due to the contribution of Anguillospora, Pyrenochaetopsis, and Bipolaris. The single exposure to TiO NPs and combined exposure with ZnO NPs promoted microbial mass and hydrolase activities, with the stimulating effect attributed to the enhanced decomposition of soluble substances. Therefore, the results highlight the importance of chemical analysis of decomposed leaves to evaluate the potential threat of metallic NPs to the function of freshwater ecosystems.
由于金属纳米粒子（NPs）频繁释放，其在环境水平下对淡水生态系统的潜在影响不容忽视。本研究选用最广泛使用的金属氧化物 ZnO NPs 和 TiO NPs（100ng/L），探究其单一及联合效应对凋落物分解的影响。尽管 ZnO NPs 和 TiO NPs 单独或联合作用均能提高 22.68%-41.17%的凋落物分解率，但在生态过程中表现出不同的毒性机制。微生物量和酶活性在急性暴露后显著增加，但在慢性暴露于 ZnO NPs 后显著降低。BG 活性是最敏感的因素，在 ZnO NPs、TiO NPs 及联合暴露 21 天后，分别降低了 66.22%、56.97%和 39.39%。此外，傅里叶变换红外光谱分析为理解促进机制提供了新的视角。ZnO NPs 的促进作用依赖于由于 Anguillospora、Pyrenochaetopsis 和 Bipolaris 的贡献，增强了难降解有机物和易降解物质的分解。TiO NPs 的单一暴露和与 ZnO NPs 的联合暴露促进了微生物量和水解酶活性，刺激作用归因于可溶性物质的增强分解。因此，研究结果强调了对分解叶化学分析的重要性，以评估金属 NPs 对淡水生态系统功能的潜在威胁。
