梯级沟渠对农业非点源氮磷的去除效率及影响因素

Removal Effi ciency and Infl uencing Factors of Nitrogen and Phosphorus from Agricultural Non-point Sources by Stepped Ditches

农业非点源污染已经成为我国环境治理不可避免的一个关键问题。通过改造后的梯级沟渠和原始沟渠对比,研究了改造梯级沟渠系统对农田退水污染物的沿程变化规律及拦截效果。结果表明,在实验周期内,梯级沟渠的TN、TP极显著负相关,TN和悬浮物及浊度极显著负相关,TP和悬浮物及浊度极显著正相关;梯级沟渠系统的TN、NH_(4)^(+)-N、TP、COD截留率分别为5.16%、38.03%、87.78%和51.76%。相较于原始沟渠TN、TP、TDP、COD的截留率为-6.80%、57.63%、16.67%、2.74%,梯级沟渠对农田退水污染物能有效去除,减轻农田周围河流负担。

Agricultural non-point source pollution has become an unavoidable key issue in my country’s environmental governance.By com-paring the reconstructed cascade ditch with the original ditches,the variation law and interception effect of the retrofit cascade ditch system on the pollutants of farmland receding water were studied.The results showed that during the experiment period,TN and TP of the stepped trenches were ex-tremely significantly negatively correlated,TN was extremely significantly negatively correlated with suspended solids and turbidity,and TP was ex-tremely significantly positively correlated with suspended solids and turbidity,NH_(4)^(+)-N,TP,COD retention rates were 5.16%,38.03%,87.78%,and 51.76%,respectively.Compared with the retention rates of TN,TP,TDP and COD in the original ditches-6.80%,57.63%,16.67%and 2.74%,the cas-cade ditches can effectively remove pollutants from farmland backwater and reduce the burden on the rivers around the farmland.