生态沟渠对村落无序排放污水截留效果的试验

Experiment of Interception Effect of Ecological Ditches on Unordered Discharge Sewage in Rural Villages

针对村落无序排放污水负荷不稳定、排放分散的特点构建生态沟渠,研究了填料类型、水力负荷对生态沟渠去除污染物的影响,在此基础上进行了暴雨径流拦截试验。结果表明:在0.86 m^(3)/(m^(2)·d)的进水负荷下,煤渣作为生态沟渠填料可以有效去除污水中的COD_(Cr)、总氮(TN)、总磷(TP),去除率分别为63.35%、55.25%和61.56%,去除效果总体优于沙石填料和球形填料;随着水力负荷增大时,生态沟渠对各污染物的去除率均有所降低,而污染去除负荷总体呈现先增大后减小的趋势;在水力负荷为3.61 m^(3)/(m^(2)·d)时,生态沟渠对COD_(Cr)、TN达到最大去除负荷,分别为48.24、5.91 g/(m^(2)·d),TP的去除负荷达到0.38 g/(m^(2)·d),对应的去除率分别为28.05%、35.85%、39.06%;不同暴雨径流方式下,生态沟渠出水中污染物浓度的动态变化特征相近,且出水中各污染物浓度的峰值均低于进水均值,表明生态沟渠能够较好地应用于村落无序排放污水治理中。

To deal with the unstable quality and quantity as well as the scattered discharge situation of rural unordered sewage,ecological ditch was constructed.And the effects of packings and hydraulic load on pollutant removal were investigated.Additionally,an experiment with simulated rainstorm runoff was carried out to study the sewage interception capacity of the ecological ditch.The results showed that under the hydraulic load of 0.86 m3/(m^(2)·d),the ecological ditches with cinder packing had obtained effective pollutants removal rate of COD_(Cr)(63.35%),TN(55.25%)and TP(61.56%)compared with those with sandstone and spherical packings.As hydraulic load increased in ecological ditches,the pollutants removal efficiencies all decreased accordingly,while the pollutants removal load first increased followed by a declined tendency.Under the hydraulic load of 3.61 m3/(m^(2)·d),the maximum removal loads of COD_(Cr) and TN were gained of 48.24 g/(m^(2)·d)and 5.91 g/(m^(2)·d),and removal load of TP was 0.38 g/(m^(2)·d),the corresponding removal rates were 28.05%,35.85%and 39.06%,respectively.Under different conditions of simulated rainstorm runoff,pollutant concentrations in effluent exhibited the similar dynamic trend and remained lower than the average concentrations in the influent,demonstrating the feasibility of ecological ditch for the interception and purification purpose ofunordered discharge sewage in rural villages.