Department of Environmental Resources Engineering, College of Environmental Science and Forestry, State University of New York, 1 Forestry Dr, Syracuse, NY, 13210, USA.
Environ Sci Pollut Res Int. 2018 Dec;25(36):36425-36437. doi: 10.1007/s11356-018-3543-4. Epub 2018 Oct 28.
Macrophytes and bacteria are key drivers of nitrogen removal in constructed wetlands. Through mesocosm experiments with vegetated submerged beds and free water surface wetlands in various operational modes, wetland configurations, and system layouts, this study developed empirical models for non-destructive estimation of plant biomass growth and associated nitrogen assimilation and explored the combined effects of multiple factors that influence microbial nitrogen removal. The above-ground biomass of individual plants was a power function of plant height for both Cyperus alternifolius and Typha angustifolia. Below- to above-ground biomass ratio was 0.38 for C. alternifolius and 2.73 for T. angustifolia. Because of greater tolerance to ammonia stress, C. alternifolius and C. papyrus grew faster than T. angustifolia. There were no significant effects of wetland type, vegetation, and plant species on microbial nitrogen removal. Microbial nitrogen removal was inhibited by free ammonia at 13.3-16.2 mg N/L. Denitrification and anammox were suppressed at dissolved oxygen greater than 1.9 mg/L. Microbial removal of ammonia in vegetated submerged beds was sensitive mainly to dissolved oxygen, pH, and influent ammonia concentration, while in free water surface wetlands, it was sensitive to influent ammonia concentration, pH, and temperature.
挺水植物和细菌是人工湿地氮去除的关键驱动因素。通过各种运行模式、湿地构型和系统布局的有植被淹没床和自由水面湿地的中观实验，本研究为植物生物量生长及其相关氮同化的非破坏性估计开发了经验模型，并探讨了影响微生物氮去除的多个因素的综合影响。香蒲和芦苇的地上生物量与植株高度呈幂函数关系。香蒲的地下到地上生物量比为 0.38，芦苇为 2.73。由于对氨胁迫的耐受性更强，香蒲和纸莎草的生长速度比芦苇快。湿地类型、植被和植物物种对微生物氮去除没有显著影响。游离氨在 13.3-16.2 mg N/L 时会抑制微生物氮去除。溶解氧大于 1.9 mg/L 时会抑制反硝化和厌氧氨氧化。有植被淹没床中微生物对氨的去除主要对溶解氧、pH 值和进水氨浓度敏感，而在自由水面湿地中，主要对进水氨浓度、pH 值和温度敏感。
