生态浮床的去污效果与机理研究

Study on Removal Effect and Mechanism in Ecological Floating-Beds

在对有植物的浮床(美人蕉床和菖蒲床)和无植物的对照床进行对比试验的基础上,通过示踪试验及物料衡算的方法研究了浮床系统的净化机理。结果表明,美人蕉床和菖蒲床对总氮(TN)、总磷(TP)及化学需氧量(CODCr)的平均去除率分别为29.5%、28.7%、23.7%和31.8%、27.9%、24.4%,平均去除负荷分别为1.141、0.111、0.684 g.m-2.d-1和1.244、0.108、0.689 g.m-2.d-1,均极显著高于对照床(p<0.01);且浮床的去污效果与植物的生长情况成显著的正相关关系(r>0.786,p<0.05)。通过底泥沉积去除氮磷是浮床系统最主要的去污途径,植物吸收对污染物去除的贡献只占10%左右。研究表明,植物有助于浮床系统内形成良好的溶解氧(DO)浓度梯度分布、使系统的水流流态更接近于反应器的理想推流流态以及通过根系的过滤沉积作用去污等,所以植物是浮床发挥净化作用的关键。

Based on comparative tests of removal effect between Ecological Floating-Beds(EFBs) planted with Canna indica and Acorus calamus and the unplanted bed,the mechanism of EFBs was investigated through the tracer study and mass balance calculation.Results of the study showed that,the average removal efficiencies of TN,TP and CODCr of EFBs planted with Canna indica and Acorus calamus were 29.5%,28.7%,23.7% and 31.8%,27.9%,24.4%,the average removal loadings were 1.141,0.111,0.684 g·m-2·d-1 and 1.244,0.108,0.689 g...