绿地系统对径流污染物净化机理的研究

Study on Decontaminating Mechanism of Green System to Runoff Pollutants

采用城市绿地和降雨系统模拟装置,研究绿地系统对径流污染物的净化机理。研究表明,模拟绿地对径流污染物的削减和污染物总量的控制有较好作用。降雨期间绿地系统对径流污染物中化学需氧量、氨氮、硝酸盐氮及总磷的去除率为32.1%-49.9%;污染物的去除主要靠土壤和植物根系的截留、吸附和吸收作用,通过分析,发现土壤对氨氮及总磷的吸附反应在常温下较易进行,对硝酸盐氮的吸附反应在常温下较难进行。降雨后微生物开始降解吸附于土壤颗粒表面和植物根系的污染物,5-8d土壤中微生物数量达到最大值,14-17d土壤污染物含量基本降到降雨前水平,土壤得到再生。

The paper uses urban greenbelt and rainfall simulator to study decontaminating mechanism of Green system to runoff pollutants. Research shows that greenbelt simulation has played a better role in reducing and controlling runoff pollutants. The removal rate of green system on the runoff pollutants is 32.1%-49.9%. The adsorption processes are carried out and it is found that the adsorption reaction on NH4^＋-N and TP at room temperature is spontaneous, but the adsorption reaction on NO3-N is difficult to be carried out. After the rainfall, microbes start to degrade the adsorbed pollutants. 5-8 d after rainfall, the number of microbes in the soil reaches the maximum, and 14-17 d later, pollutants in the soil reduce to the basic level before the rainfall. So the soil is renewable.