Journal of Ecology and Rural Environment ›› 2022, Vol. 38 ›› Issue (8): 1076-1083.doi: 10.19741/j.issn.1673-4831.2021.0460

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Effect of Flow Disturbance Intensity on Nitrogen Release from Bottom Muddy of Plateau Rural Ditches

ZHENG Shu-jun1, WANG Tie-yun1, LIU Yun-gen1,2, DU Peng-rui1, WANG Yan1,2, JIA Yu-jie1, WEN Ming-fa3   

  1. 1. College of Ecology and Environment, Southwest Forestry University, Kunming 650224, China;
    2. Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas, Kunming 650224, China;
    3. Yunnan Deyuan Lüchuang Environmental Protection Technology Co. Ltd., Kunming 650041, China
  • Received:2021-07-24 Online:2022-08-25 Published:2022-08-23

Abstract: To investigate the effect of hydrodynamic disturbance on endogenous nitrogen (N) release in plateau mountainous rural ditches, N concentrations in overlying water under various flow disturbance intensities (0, 5, 15, 30, 60 L·h-1) were analyzed by a simulation experiment. The results show that:(1) Sediment N can be released into overlying water by the initial hydrodynamic disturbance and reaches the highest values of NH4+-N and TN at 5 and 60 L·h-1 flow disturbance intensity, respectively. After 30 days, N concentration in the undisturbed water was higher than that in the disturbed water; (2) Sediment TN contents increased with the increasing of disturbance intensity, which however were lower than the background values, showing 0 < 5 < 30 < 15 < 60 L·h-1; (3) The contents of different forms of transformable nitrogen (TTN) were in the order of strong oxidant extractable-N (SOEF-N) > strong alkali extractable-N (WAEF-N) > ion exchange-N (IEF-N) > weak acid extractable-N (SAEF-N), with releasing tendentiousness of IEF-N > WAEF-N > SAEF-N > SOEF-N. All N fractions of the sediment were at the lowest values under undisturbed treatment, indicating that the disturbance of flow benefits the N settlement in sediments, thus decreasing the risk of N to the surrounding environment.

Key words: rural ditch, sediment, nitrogen release, disturbance

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