Nanoplastic pollution has become one of the most pressing environmental issues, and its bioaccumulation in aquatic environment also causes a great difficulty in treatment. Therefore, this work investigated the microbial dynamics of mainstream anaerobic ammonia oxidizing (anammox) process to treat the wastewater containing typical nanoplastics, as well as the fate and regulation mechanism of polystyrene nanoparticles (PS-NPs) with different concentrations. The results showed that 0.1–0.5 mg L-1 of PS-NPs had no significant effect on the nitrogen removal efficiency (NRE). When the concentration of PS-NPs increased from 0.5 mg L-1 to 2 mg L-1, the NRE of R1 with PS-NPs decreased from 94.9 ± 2.3 % to 77.0 ± 1.6 %, while the control reactor R0 maintained a stable NRE. Notably, the relative abundance of Ca. Kuenenia decreased from 17.4 % to 14.8 %, and that of Ca. Brocadia slightly decreased from 5.9 % to 5.0 % in R1. In addition, PS-NPs induced oxidative stress in anammox consortia, leading to the significant increase in reactive oxygen species (ROS) and lactate dehydrogenase (LDH) as well as cell membrane damage. PS-NPs also downregulated the content of heme c and further inhibited anammox activity. Based on the molecular docking simulation and western blotting, cold shock proteins (CSPs) could bind to PS-NPs and reduce the performance of anammox processes at low temperatures.

中文翻译：

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聚苯乙烯纳米颗粒在低温下调节主流厌氧氨氧化工艺中的微生物应激反应和冷适应


纳米塑料污染已成为最紧迫的环境问题之一，其在水生环境中的生物积累也造成了极大的处理难度。因此，本工作研究了主流厌氧氨氧化 （anammox） 工艺处理含有典型纳米塑料的废水的微生物动力学，以及不同浓度聚苯乙烯纳米颗粒 （PS-NPs） 的命运和调控机制。结果表明，0.1–0.5 mg L-1 的 PS-NPs 对脱氮效率 （NRE） 没有显着影响。当 PS-NPs 浓度从 0.5 mg L-1 增加到 2 mg L-1 时，含 PS-NPs 的 R1 的 NRE 从 94.9 ± 2.3 % 降低到 77.0 ± 1.6 %，而对照反应器 R0 保持稳定的 NRE。值得注意的是，在 R1 中，Ca. Kuenenia 的相对丰度从 17.4 % 下降到 14.8 %，而 Ca. Brocadia 的相对丰度从 5.9 % 略微下降到 5.0 %。此外，PS-NPs 诱导厌氧氨氧化酶联盟的氧化应激，导致活性氧 （ROS） 和乳酸脱氢酶 （LDH） 显著增加以及细胞膜损伤。PS-NPs 还下调血红素 c 的含量并进一步抑制厌氧氨氧化活性。基于分子对接模拟和 western blotting，冷休克蛋白 （CSPs） 可以在低温下与 PS-NPs 结合并降低厌氧氨氧化过程的性能。