垂直-水平流人工湿地处理农村污水效果及影响因素

Treatment Effect of Vertical-horizontal Flow Constructed Wetland System on Rural Wastewater and Its Influencing Factors

为了提升水环境质量,进一步提高农村分散处理设施的出水水质,构建了垂直-水平流湿地系统对其出水进行深度处理。通过设置沿程采样点,取样检测TN、NH-N、TP等水质指标,分析其沿程变化以及季节、水力负荷对去除效果的影响。结果表明,垂直-水平流湿地系统对氮的去除主要发生在垂直流段,去除率达48.5%;磷在垂直流和水平流段均得到有效去除,去除率为41.0%;季节变化影响对氮、磷的去除效果,夏、秋季节TN、NH-N、TP去除率高达46%、47%、42%。建议湿地运行过程中的水力负荷<0.5 m^(3)/(m^(2)·d),进水氮负荷<5 g/(m^(2)·d),出水水质基本满足地表Ⅴ类水标准。湿地构建中可填充沸石、石灰石等填料,合理选择植物,以增强对氮、磷的去除。

In order to improve the quality of water environment and further improve the discharge standard of treatment facilities,a vertical-horizontal flow wetland system was constructed for advanced treatment of tail wastewater.By setting sampling points along the system,the change of TN,NH-N,TP and other water quality indicators was analyzed,and the influence of season and hydraulic load on pollutants removal effect was investigated.It was concluded that the removal of nitrogen in the vertical-horizontal flow wetland system mainly occurred in the vertical flow section,with a removal rate of 48.5%;phosphorus was effectively removed in both vertical and horizontal flow sections,with a removal rate of 41.0%.Season affected the removal efficiency of both nitrogen and phosphorus,the removal rates of TN,NH-N and TP in summer and autumn were as high as 46%,47%and 42%,respectively.It was suggested that the hydraulic load of the wetland should be less than 0.5 m^(3)/(m^(2)·d),the nitrogen load of the inlet water should be less than 5 g/(m^(2)·d),which could ensure that the effluent quality basically met the classⅤstandard of the surface water.Zeolite and limestone can be used as the filter materials,and plants can be reasonably selected,which also enhances the removal of nitrogen and phosphorus.