寒旱区不同类型沟对非点源污染氮磷拦截效应及相关影响因素研究

Study on Interception Effect and Relevant Influencing Factors of Nitrogen and Phosphorus from Non-point Source Pollution by Different Types of Ditches in Cold and Arid Region

为阐明寒旱区不同类型沟对非点源污染氮磷拦截的影响,采用室内静、动态模拟和方差分析相结合的方法,分析寒旱区不同类型沟对非点源污染氮磷的拦截效果,并在生态沟动态实验中考虑了进水氮磷浓度、进水流量和进水盐度3个因素,探索其对生态沟拦截非点源污染氮磷的影响。结果表明:①静态、不同水力停留时间(HRT)条件下,生态沟对污水中氮磷拦截效果最好,且其对低、中和高进水氮磷浓度的平均去除率分别为TN:78.93、69.82、58.61,TP:90.31、84.47、76.71;②动态、HRT48 h条件下,生态沟对高进水氮磷浓度的日平均拦截量分别比低、中进水氮磷浓度多TN:75.91、55.58,TP:67.08、44.02;③动态、中进水氮磷浓度条件下,生态沟对低、中和高进水流量中TN、TP的平均去除率分别为TN:41.52、31.31、26.59,TP:72.36、64.89、53.39;④动态、HRT48 h和中进水氮磷浓度条件下,生态沟对低、中和高进水盐度中TN、TP的平均去除率呈现先增加后降低的趋势;⑤不同类型沟、进水氮磷浓度和进水流量对生态沟拦截TN、TP的影响有显著性差异(P<0.05),但进水盐度对生态沟拦截TN、TP的影响无显著性差异(P>0.05)。可见,生态沟对寒旱区非点源污染氮磷有较好的拦截作用,研究结果可为非点源污染防控及治理提供参考。

In order to clarify the influence of different types of ditches on nitrogen and phosphorus interception of non-point source pollution in cold and dry areas,this paper used a combination of indoor static and dynamic simulation and variance analysis to analyze the interception effect of different types of ditches on nitrogen and phosphorus from non-point source pollution in cold and dry areas.And in the dynamic experiment of the ecological ditch,the three factors of influent nitrogen and phosphorus concentration,influent flow and influent salinity were considered to explore their effects on the interception of non-point source pollution nitrogen and phosphorus in the ecological ditch.The results showed that:①under the condition of static state and different hydraulic residence time(HRT),the interception effect of TN and TP in the ecological ditch was the best,and the average removal rates of TN and TP in low,middle and high influent nitrogen and phosphorus concentration were 78.93%,69.82%,58.61%and 90.31%,84.47%,76.71%,respectively;②under the condition of dynamic and 48 h HRT,the average daily interception of TN and TP from high influent nitrogen and phosphorus concentration by ecological ditch were higher than that of low and medium influent nitrogen and phosphorus concentration by 75.91%,55.58%and 67.08%,44.02%,respectively;③under the condition of dynamic and medium influent nitrogen and phosphorus concentration,the average removal rates of TN and TP in low,middle and high influent flow are 43.09%,36.29%,29.72%and 79.77%,76.58%,70.68%respectively;④under the condition of dynamic,48 h HRT and medium influent nitrogen and phosphorus concentration,the average removal rate of TN and TP in the low,middle and high influent salinity increased first and then decreased in the ecological ditch;⑤there were significant differences in TN and TP intercepted by different types of ditches,influent nitrogen and phosphorus concentration and influent flow(P<0.05),but there was no significant difference in TN and TP intercepted by different influent salinity(P>0.05).It can be seen that ecological ditch has a good interception effect on nitrogen and phosphorus pollution from non-point sources in cold and dry regions.The research results can provide reference for the prevention,control and treatment of non-point source pollution.