低温条件下生物滞留池中的氮素迁移转化。
Nitrogen transfer and transformation in bioretention cells under low temperature conditions.
机构信息
Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road, No. 13, Xi'an 710055, China.
Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road, No. 13, Xi'an 710055, China.
出版信息
Sci Total Environ. 2023 May 1;871:162087. doi: 10.1016/j.scitotenv.2023.162087. Epub 2023 Feb 9.
The nitrogen removal effect of traditional bioretention cells is generally poor under low temperature conditions, with significant levels of fluctuation and leaching often reported. Therefore, the migration characteristics of nitrogen were explored in bioretention cells under low temperature conditions, with the aim of improving the nitrogen removal effect. Four groups of modified collapsible loess bioretention cells were constructed and operated at 1, 5, 10 and 25 °C. The nitrogen removal effect of the cells was determined at different temperatures and the nitrogen migration and transformation characteristics under low temperature conditions were discussed. Experimental results showed that during the rainfall period, the ammonia nitrogen removal efficiency remained similar at different temperatures (above 97 %), while the nitrate nitrogen removal efficiency varied significantly at 1, 5, 10 and 25 °C, from 28.15 %-65.22 %, 96.68 %-98.8 %, 96.75 %-98.88 % and 80.14 %-96.72 %, respectively. In addition, nitrate nitrogen accumulation occurred in the filler during rainfall events, with lower temperature conditions increasing the final concentration of nitrate nitrogen accumulated. Following a rainfall event, the content of nitrate nitrogen in the filler decreased significantly over a 60 h dry period. However, the nitrate nitrogen reduction rate was significantly lower under low temperature conditions, than at 25 °C. Overall, low temperature conditions had a negative effect on the accumulation of nitrate nitrogen in the filler during rainfall events, as well as the transformation and migration of nitrate nitrogen within the filler during drought periods, with the adverse effects most significant at temperatures lower than 5 °C.
传统生物滞留池在低温条件下的脱氮效果一般较差，常报道有明显的波动和淋失。因此，本研究在低温条件下探索了生物滞留池内氮的迁移特性，以期提高脱氮效果。构建并运行了四组改良可缩性黄土生物滞留池，分别在 1、5、10 和 25°C 下运行。在不同温度下测定了细胞的脱氮效果，讨论了低温条件下氮的迁移转化特性。实验结果表明，在降雨期内，不同温度下氨氮去除效率相似（均高于 97%），而硝酸盐氮去除效率在 1、5、10 和 25°C 下差异显著，分别为 28.15%-65.22%、96.68%-98.8%、96.75%-98.88%和 80.14%-96.72%。此外，在降雨事件中，填料中会发生硝酸盐氮积累，较低的温度条件会增加最终积累的硝酸盐氮浓度。在一次降雨事件后，60 h 的干燥期内，填料中硝酸盐氮的含量显著下降。然而，在低温条件下，硝酸盐氮的还原速率明显低于 25°C 时。总体而言，低温条件对降雨事件中填料中硝酸盐氮的积累以及干旱期内填料中硝酸盐氮的转化和迁移有负面影响，在温度低于 5°C 时影响最为显著。
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