高位湖滩湿地在农业面源污染河水中的应用

The Application of Lakeshore Raised Constructed Wetlands in Agricultural Non-point Source Polluted River Water

[目的]研究高位湖滩湿地对农业面源污染河水的净化效果。[方法]根据抚仙湖北岸受农业面源污染入湖河流广南营沟、沙盆河水流量大、污染物浓度较低的特点,在河口区湖滩地采用拦污沉沙—二级表流湿地—砂砾床工艺路线设计了高位湖滩湿地,通过对湿地进水量、进出水质周年监测与分析。[结果]该系统对SS、CODCr、TN、TP平均去除率分别为90%、54%、50%、66%,设计水力负荷为0.47 m^3/(m^2·d)时,净化效果最佳。该工艺拦污沉沙区域,可以有效降低SS的含量,减轻后续湿地系统处理的压力,防止填料堵塞;二级表流—砂砾床湿地,脱氮除磷效果较好,有效削减入湖污染负荷量。[结论]该湿地系统适用于农业面源污染河水,具有良好的经济、环境、生态效益。

[Objective]The research aimed to study the water quality purification effect of the wetland on the agricultural non-point source polluted river water. [Method] Based on the agricultural non-point source polluted river water of the Guangnanyinggou and Shapen river which on the north shore of the Lake Fuxian. The river was characterized by high flow rate and low pollutant concentration. We constructed Lakeshore Raised Constructed Wetlands in lakeside of Lake Fuxian. The process route was designed with the sedimentation tanks,a second surface flow wetland and gravel bed wetland. [Result] The average removal rate of SS,CODCr,TN and TP was 90%,54%,50% and 66% respectively. When the designed hydraulic load was 0. 47 m^3（/m^2·d）,the best purification effect was achieved. The sand silting area of the process could effectively reduce the content of SS,reduce the pressure of the subsequent wetland system treatment,and prevent the plugging of the filler. The secondary surface flow-gravel bed wetland has a good effect of nitrogen and phosphorus removal,effectively reducing the pollution load into the lake.[Conclusion] Lakeshore Raised Constructed Wetlands can be applied to the agricultural non-point source polluted river water. It has good economic,environmental and ecological benefits.