不同运行期排水沟渠中氮的净化效应实验研究

The Purifying Effect of Nitrogen in Drainage Ditches of Different Operation Periods

以模拟排水沟渠静态实验为基础,以典型非点源溶质氨氮和硝氮为例,分析了不同运行期排水沟渠中氨氮和硝氮浓度的变化过程与影响机制。结果表明:不同运行期排水沟渠对水体中氨氮、硝氮均具有较强的净化效应,并表现出"快速净化,波动平衡"的特点,其中氨氮浓度的下降速度快于硝氮,氨氮"波动平衡"的浓度范围(≤2 mg·L-1)低于硝氮(≤3 mg·L-1);实验初始阶段,运行期的不同对沟渠中氨氮和硝氮的净化速率有较大的影响,初始阶段的净化速率表现为:多年沟渠>7月龄沟渠>1月龄沟渠,除不同运行期非生态沟渠中硝氮的净化速率有显著性差异外,其余阶段均无显著性差异;不同运行期生态沟渠和非生态沟渠中氨氮浓度的变化过程,除7月龄沟渠的"波动平衡"阶段有显著性差异(P=0.03<0.05)外,其余均无显著性差异;硝氮浓度的变化过程,1月龄和7月龄沟渠在实验初期和"波动平衡"阶段均有显著性差异,多年沟渠的净化趋势相似,无显著性差异。综上所述,本实验初步证明了增长沟渠运行期能够增强沟渠对氮素的净化能力,这对进一步探究排水沟渠的发育过程和生态沟渠的合理化设计与管理具有一定的借鉴意义。

Based on the experiment about static simulation of drainage ditches, the article used typical non-point source soluble nitrate and ammonia nitrogen as an example tO analyze the changing process and study the effects of nitrate nitrogen and ammonia nitrogen concentrations in the simulated drainage water of different operation periods. The results showed that ammonia nitrogen and nitrate nitrogen in the drainage ditches of different operating periods could be purified effectively. The purification process had the characteristics of ＇fast purification, wave balance＇, in which ammonia nitrogen concentration decreased faster than nitrate nitrogen and the range of ammonia nitrogen concentration in the ＇wave balance＇ stage （ ≤ 2 mg· L -1 ） was lower than nitrate nitrogen （ ≤ 3 mg· L-1）. The different operation periods had great influence on the purification rate of ammonia nitrogen and nitrate nitrogen in the ditches at the initial stage of the experiment, in which the purification rate：The multi-years ditch〉 the 7-month-old ditch〉the 1-month-old ditch. In addition to the nitrate purification rate of nitrate nitrogen in non-ecological ditches of different operation had significant difference, no significant difference in the remaining stages; There was no significant difference in the change of ammonia nitrogen concentration in the ditch at different operating periods, except for the ＇fluctuating balance＇ stage of the 7-month-old ditch （P=0.03〈0.05）. There was significant difference in the early stage and the ＇ wave balance＇ stage of the purification process about nitrate nitrogen in the 7-month-old ditch and the 1-month-old ditch, the trend of purification for the multi-years ditch was similar, and no significant difference. In summary, the experiment proved that the growth of ditch operation periods could enhance the ability of purifying nitrogen,which had certain significance for further exploring the development process of the drainage ditch, rational design and management of the ecological ditches.