一种新型双重轮休式潜流湿地及其抗堵塞与去污效果

Anti-clogging and decontamination effects of a new type of dual rotation subsurface flow wetland

为解决垂直潜流湿地易堵塞问题,设计了一种新型双重轮休式潜流湿地,该新型湿地通过控制进出水阀门开关实现预处理池和主体池上层的双重轮休以及水流方向的周期性改变,以提高防堵塞效果。在4个不同轮休周期工况下进行新型湿地对污染物去除效果的试验,确定其最佳轮休周期为5 d;在5 d轮休周期下运行新型湿地与传统潜流湿地,进行抗堵塞能力和去污效果的对比,运行40 d、140 d、160 d后,新型湿地的孔隙率分别为48.43%、46.36%和46.21%,传统湿地的孔隙率分别为46.89%、38.72%和44.37%,新型湿地基质孔隙率下降幅度小于传统湿地;运行160 d后,新型湿地NH_(3)-N、NO_(3)^(-)-N、TN、COD、TP去除率分别为60.40%、70.80%、56.53%、53.12%和48.30%,传统湿地中这些污染物去除率分别为34.99%、51.70%、41.43%、29.84%和47.06%,新型湿地污染物去除率高于传统湿地,且新型湿地中这些污染物去除率下降幅度均小于传统湿地,整个运行过程中去除效果较为稳定。该新型湿地为有效缓解堵塞问题提供了一种新的解决途径。

A new type of dual rotation subsurface flow wetland was designed in order to solve the easy clogging problem of the vertical subsurface flow wetland.This new type of wetland realizes dual rotation of the pretreatment pool and the upper layer of the main pool and periodical change of the water flow direction through controlling the switch of the inlet and outlet valves,in order to improve the anti-clogging effect.A test on the pollutant removal effect of the new type of wetland was conducted under conditions of four different rotation periods,and the optimal rotation period was determined as five days.The anti-clogging ability and decontamination effect of the new type of wetland operated under the 5-day rotation period and the traditional subsurface flow wetland were compared.After 40,140,and 160 days of operation,the porosities of the new type of wetland were 48.43%,46.36%,and 46.21%,respectively,and the values of the traditional wetland were 46.89%,38.72%,and 44.37%,respectively.The substrate porosity of the new type of wetland decreased less than that of the traditional wetland.Moreover,the removal rates of NH_(3)-N,NO_(3)^(-)-N,TN,COD,and TP of the new type of wetland after 160 days were 60.40%,70.80%,56.53%,53.12%,and 48.30%,respectively,and the values of the traditional wetland were 34.99%,51.70%,41.43%,29.84%,and 47.06%,respectively.The removal rates of pollutants of the new type of wetland were higher than those of the traditional wetland,and the values of the new type of wetland decreased less than those of the traditional wetland.The new type of wetland has a relatively stable pollutant removal effect throughout the operation process,providing a new method to effectively alleviate the clogging problem.