Yang Jinyi, Zhang Tuoshi, Ma Shengjun, Shang Jiacheng, Li Lixin, Ning Yucui, Zhao Xinyue
College of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China.
J Hazard Mater. 2025 Jun 5;489:137540. doi: 10.1016/j.jhazmat.2025.137540. Epub 2025 Feb 7.
The presence of microplastics (MPs) in wastewater poses significant threats to ecosystems. Although constructed wetlands (CWs) demonstrate effective removal of microplastics, their efficiency is often limited by various environmental variables and system equilibrium factors. This study introduces Eisenia fetida to enhance the ecological performance of constructed wetlands and improves their removal efficiency. The findings revealed that the addition of earthworms significantly increased the removal efficiencies of polylactic acid (PLA) microplastics, chemical oxygen demand, total nitrogen, and ammonium nitrogen, with respective improvements of 13.5 %, 8.4 %, 9.7 %, and 10.5 %, respectively. Notably, the ingestion of polylactic acid microplastics by earthworms led to a substantial increase in the abundance of microorganisms, such as Actinobacteria, that were associated with microplastic degradation. Furthermore, microbial communities involved in nitrogen cycling were notably enriched, with a 12.4 % increase in nitrogen-fixing microbes and a 4.3 % increase in nitrifying microbes. These findings suggested that earthworms, through the restructuring of their gut microbial communities, not only facilitated efficient polylactic acid degradation but also enhanced nitrogen cycling processes. This provides a novel ecological mechanism for improving pollutant management and nutrient recycling in constructed wetlands.
废水中微塑料（MPs）的存在对生态系统构成了重大威胁。尽管人工湿地（CWs）对微塑料具有有效的去除能力，但其效率往往受到各种环境变量和系统平衡因素的限制。本研究引入赤子爱胜蚓以提高人工湿地的生态性能并提升其去除效率。研究结果表明，添加蚯蚓显著提高了聚乳酸（PLA）微塑料、化学需氧量、总氮和铵态氮的去除效率，分别提高了13.5%、8.4%、9.7%和10.5%。值得注意的是，蚯蚓摄取聚乳酸微塑料导致与微塑料降解相关的微生物（如放线菌）丰度大幅增加。此外，参与氮循环的微生物群落显著富集，固氮微生物增加了12.4%，硝化微生物增加了4.3%。这些发现表明，蚯蚓通过重组其肠道微生物群落，不仅促进了聚乳酸的高效降解，还增强了氮循环过程。这为改善人工湿地中的污染物管理和养分循环提供了一种新的生态机制。
