Abstract Climate-related issues constitute an important obstacle for the development of treatment wetland (TW) applications in regions with freezing winter temperatures. The aim of the present study was to evaluate the efficiency of a new configuration of TWs based on the vertical flow (VF) configuration. The proposed TWs system is planted with a willow species (Salix miyabeana SX67) and including design adaptations for cold climate operation. Two different flow modes for winter-time operation were proposed: percolated and saturated with continuous artificial aeration. The pilot-scale systems were tested with municipal wastewater, at an organic loading ranging from 5 to 20 g CBOD5 m−2 d−1. The pilot TWs were successfully operated for 22 months despite freezing winter temperatures reaching as low as −32 °C. Willow development was normal, with evapotranspiration ranging from 19 to 23 mm/d in July 2017 for the pilot TWs at an organic loading of 10 g CBOD5 m−2 d−1. Organic matter removal efficiency was high for all pilot TWs, with an average 91% COD and 81% TSS removal. Nitrification was essentially complete during the summer period and remained high for pilot TWs operated under percolating flow mode in winter but was lower for the saturated flow mode, probably due to insufficient air supply. Our study confirms the successful application of a modified version of VF TW in regions with freezing air temperatures.

中文翻译：

---

寒冷气候条件下单级垂流处理人工柳树湿地两年表现

摘要 与气候相关的问题构成了在冬季寒冷地区发展处理湿地 (TW) 应用的重要障碍。本研究的目的是评估基于垂直流 (VF) 配置的新 TW 配置的效率。拟议的 TWs 系统种植了柳树种 (Salix miyabeana SX67)，包括针对寒冷气候操作的设计适应性。提出了冬季运行的两种不同流动模式：渗透和饱和连续人工曝气。中试规模的系统在城市污水中进行了测试，有机负荷范围为 5 到 20 g CBOD5 m-2 d-1。尽管寒冷的冬季气温低至 -32 °C，但试点 TW 仍成功运行了 22 个月。柳树发育正常，2017 年 7 月，试点 TW 的蒸散量为 19 至 23 毫米/天，有机负荷为 10 克 CBOD5 m-2 d-1。所有中试 TW 的有机物去除效率都很高，平均去除了 91% 的 COD 和 81% 的 TSS。硝化在夏季基本完成，冬季在渗透流模式下运行的中试 TW 保持高水平，但在饱和流模式下硝化较低，可能是由于空气供应不足。我们的研究证实了 VF TW 的改进版本在寒冷气温地区的成功应用。硝化在夏季基本完成，冬季在渗透流模式下运行的中试 TW 保持高水平，但在饱和流模式下硝化较低，可能是由于空气供应不足。我们的研究证实了 VF TW 的改进版本在寒冷气温地区的成功应用。硝化在夏季基本完成，冬季在渗透流模式下运行的中试 TW 保持高水平，但在饱和流模式下硝化较低，可能是由于空气供应不足。我们的研究证实了 VF TW 的改进版本在寒冷气温地区的成功应用。