摘要
以我国亚热带农业面源污染防控工程——生态沟渠为研究对象,在2013~2014年对其径流量和每月进出口水质中NH^+_4-N、NO^-_3-N和TN的质量浓度进行监测,通过分析生态沟渠在不同时间段对不同形态氮素的去除差异,探讨了生态沟渠对面源污染中氮素迁移的拦截效应.结果表明,2 a内生态沟渠对NH^+_4-N、NO^-_3-N和TN的平均去除率分别为77.8%、58.3%和48.7%;拦截量分别为38.4、59.6和171.1 kg·a^(-1);进水中无机态氮NO^-_3-N和NH^+_4-N之和占TN质量分数的平均值为47.5%,出水中平均值为33.6%,比进水显著降低(P<0.01).2014年生态沟渠中水生植物全部改种为绿狐尾藻后,对NO^-_3-N和TN的拦截率比2013年分别增加了30.5%和18.2%,表明种植绿狐尾藻进一步提升了生态沟渠对氮素的拦截能力.可见,生态沟渠对农区地表径流中氮素迁移有较好的拦截作用,可作为一项重要的农业面源氮污染防控技术.
Interception effects of an ecological ditch,used to control agricultural non-point source pollution in subtropical China,on nitrogen transport in surface runoff were studied by monthly measuring the runoff volume and concentrations of ammonium nitrogen（ NH^＋4-N）,nitrate nitrogen（ NO^-3-N） and total nitrogen（ TN） at the ditch inlet and outlet from 2013 to 2014. In addition,differences of NH^＋4-N,NO^-3-N and TN removal were compared between 2013 and 2014. The results showed that the study ecological ditch worked effectively in N removal with average NH^＋4-N,NO^-3-N and TN removal rates of 77. 8%,58. 3%,and 48. 7%; and their interception rates were 38. 4,59. 6,and 171. 1 kg·a^（-1）,respectively. The average proportion of NH^＋4-N and NO^-3-N in TN was 47. 5%at inlet,and 33. 6% at outlet,which was significantly lower than that at inlet（ P 0. 01）. All hydrophytes in the ecological ditch were replaced by Myriophyllum aquaticum in 2014,which led to the increased average NO^-3-N and TN removal rates of 30. 5% and18. 2%,respectively,Compared to in 2013. The vegetation of Myriophyllum aquaticum was beneficial to the improvement of N interception in ecological ditch. These findings clearly demonstrated that ecological ditch can substantially reduce N loss from surface runoff and be used as an important technique to prevent agricultural non-point N pollution.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2016年第5期1717-1723,共7页
Environmental Science
基金
"十二五"国家科技支撑计划项目(2014BAD14B01)
湖南省战略性新兴产业成果转化项目(2015GK1014)
湖南省科技支撑计划项目(2015NK3003)
关键词
生态沟渠
农业面源污染
氮
拦截
绿狐尾藻
ecological ditch
non-point agriculture pollution
nitrogen
interception
Myriophyllum aquaticum
