蔬菜浮床对城市富营养化景观水体的净化效果研究

Purification of Floating Vegetable Bed on City Landscape Eutrophication Water

针对城市居住小区和公共园林景观水体水质逐渐恶化的现象,探索通过构建空心菜和韭菜等蔬菜浮床的方法对景观水体进行净化。室内、室外实验结果均表明,蔬菜浮床对富营养化水体中的氮、磷具有良好的去除效果。其中,室内系统各营养物质的去除率分别为19.18%(TN)、19.55%(NH_4^+-N)、11.97%(NO_3^--N)、12.38%(TP);室外系统平均去除率分别为12.34%(TN)、12.49%(NH_4^+-N)、9.40%(NO_3^--N)、7.52%(TP)。为了评估浮床蔬菜的食用安全性,本研究对蔬菜体内部分重金属含量进行了测定,结果表明,两种蔬菜体内的铅和汞含量均超出《食品安全国家标准-食品中污染物限量》。蔬菜浮床具有显著的水体净化效果,为城市环境有限空间内的富营养化水体净化方式提供借鉴,是一种健康的绿色发展方式,但浮床蔬菜的食用安全性往往取决于水体环境特征,需进行相关评估。

In recent years, lots of city landscape water quality is getting worse and worse. In this study,we developed the spinach and leeks floating beds in order to find an innovation landscape water purification method. The results showed that floating vegetable bed had a very good remediation effects on nitrogen and phosphorus in the city landscape eutrophication water. The nutrients removal rate of the out-door system was12.34%（TN）, 12.49%（NH4＋-N）, 9.40%（ NO3--N） and 7.52%（TP）, while the in-door system was higher which was 19.18%（TN）, 19.55%（NH4＋-N）, 11.97%（NO3--N） and 12.38%（TP） respectively. The heavy metal content in the vegetables from the floating bed was also detected in order to evaluate the vegetable safety as food supply.The Pd and Hg content in both of the vegetables had exceeded the 〈national criteria of food safety〉. Vegetable floating bed will play an important role in etrophication water remediation in the future. However, safety detection should be carefully conducted before the vegetables from floating bed become a kind of food supply, depending on the characteristics of the water body.