Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 211189, China.
Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 211189, China.
Environ Pollut. 2023 Jun 1;326:121259. doi: 10.1016/j.envpol.2023.121259. Epub 2023 Feb 16.
Macrophytes play the important roles in purifying pollutants of constructed wetlands (CWs), while their effects on CWs exposed to micro/nano plastics are not clear. Therefore, planted and unplanted CWs were established to reveal the impacts of macrophytes (Iris pseudacorus) on the overall performance of CWs under polystyrene micro/nano plastics (PS MPs/NPs) exposure. Results showed that macrophytes effectively enhanced the interception capacities of CWs to PS NPs, and significantly promoted the removal of nitrogen and phosphorus after exposed to PS MPs/NPs. Meanwhile, macrophytes improved the activities of dehydrogenase, urease, and phosphatase. Sequencing analysis showed that macrophytes optimized the composition of microbial communities in CWs and stimulated the growth of functional bacteria involved in nitrogen and phosphorus transformation. Moreover, macrophytes further altered the absolute abundance of nitrogen transformation functional genes (amoA, nxrA, narG and nirS). Functional annotation analysis revealed that macrophytes promoted metabolic functions such as Xenobiotics, Amino acids, Lipids metabolism and Signal transduction, ensuring the metabolic balance and homeostasis of microbes under PS MPs/NPs stress. These results exhibited profound implications for the comprehensive evaluation on the roles of macrophytes in CWs for treating wastewater containing PS MPs/NPs.
植物在净化人工湿地（CWs）中的污染物方面发挥着重要作用，但其对暴露于微/纳米塑料的 CWs 的影响尚不清楚。因此，本研究建立了种植和未种植的 CWs，以揭示在聚苯乙烯微/纳米塑料（PS MPs/NPs）暴露下，植物对 CWs 整体性能的影响。结果表明，植物有效地增强了 CWs 对 PS NPs 的截留能力，并在暴露于 PS MPs/NPs 后显著促进了氮磷的去除。同时，植物提高了脱氢酶、脲酶和磷酸酶的活性。测序分析表明，植物优化了 CWs 中微生物群落的组成，并刺激了参与氮磷转化的功能细菌的生长。此外，植物进一步改变了氮转化功能基因（amoA、nxrA、narG 和 nirS）的绝对丰度。功能注释分析表明，植物促进了包括外源性化合物、氨基酸、脂类代谢和信号转导在内的代谢功能，确保了在 PS MPs/NPs 胁迫下微生物的代谢平衡和内稳态。这些结果对全面评估植物在 CWs 处理含 PS MPs/NPs 废水中的作用具有重要意义。
