School of Environmental Science and Engineering, Tianjin Engineering Center for Technology of Protection and Function Construction of Ecological Critical Zone, Tianjin University, Tianjin 300350, China.
School of Resources and Environment, Anhui Agricultural University, Hefei 230036, China.
J Environ Manage. 2024 Nov;370:122546. doi: 10.1016/j.jenvman.2024.122546. Epub 2024 Sep 19.
To improve the treatment performance of constructed wetlands under low-temperature conditions, this study investigated the effects of plant species on wastewater treatment performance at low temperature and the associated microbiological characteristics in a subsurface vertical-flow constructed wetland (VFCW) with step-feeding. The results showed that the redox microenvironment in the VFCW filter with step-feeding could be restored and optimized by planting appropriate species that can tolerate low temperature, ensuring a high nitrification performance for the system. Correspondingly, the abundance and activity of three functional microbes (namely nitrifiers, denitrifiers, and anammox bacteria) increased to different degrees in the system, eventually ensuring ideal nitrogen removal by the VFCW. Compared with the VFCW planted with Phragmites australis and Acorus gramineus, the operation performance of the VFCW planted with Iris wilsonii could be recovered at low temperature, and its chemical oxygen demand, total phosphorus, total nitrogen, and ammonium nitrate removal rates could respectively reach 95.7%, 99.2%, 93.0%, and 94.4%, respectively. Moreover, nitrogen removal in the system relied on the nitrification/denitrification and partial denitrification - anaerobic ammonium oxidation processes. Nitrosomonas, Nitrospira, Thauera, and Candidatus Brocadia were the four dominant bacterial genera in the filter layer.
为了提高低温条件下人工湿地的处理性能，本研究考察了植物物种对低温下污水的处理性能的影响，以及在具有阶式进料的地下垂直流人工湿地（VFCW）中的相关微生物特性。结果表明，通过种植能够耐受低温的合适物种，可以恢复和优化阶式进料 VFCW 过滤器中的氧化还原微环境，从而确保系统具有高硝化性能。相应地，系统中三种功能微生物（即硝化菌、反硝化菌和厌氧氨氧化菌）的丰度和活性都有不同程度的增加，最终确保了 VFCW 的理想脱氮效果。与种植芦苇和菖蒲的 VFCW 相比，种植黄菖蒲的 VFCW 可以在低温下恢复运行性能，其化学需氧量、总磷、总氮和硝态氮去除率分别达到 95.7%、99.2%、93.0%和 94.4%。此外，系统中的氮去除依赖于硝化/反硝化和部分反硝化-厌氧氨氧化过程。硝化菌、硝化螺菌、陶厄氏菌和布鲁卡氏菌是过滤层中的四个主要细菌属。
