State Key Joint Laboratory on Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
Changzhou Environmental Technology Development and Promotion Center, Changzhou 213022, PR China.
Sci Total Environ. 2014 Jul 1;485-486:596-603. doi: 10.1016/j.scitotenv.2014.03.103. Epub 2014 Apr 17.
To investigate the effect of the eco-remediation on nutrients and heavy metals in river water and sediment, a field study was carried out in a site of a 2-year eco-remediation mainly using planted floating bed system in an urban river in China. Before remediation, the tested properties of water and sediment in the will-be remediated area were not different from the control area, except higher concentrations of chemical oxygen demand (COD) and total nitrogen (TN) in the river water. After remediation, the remediation area showed effective removal of in-stream nutrients and elevation of dissolved oxygen and transparency. Compared to the control area, the remediation area had higher concentration of nitrate and lower concentrations of COD, ammonium, Mn and hexavalent Cr in the river water after a 2-year remediation. The remediation area also showed higher concentrations of organic carbon, TN, nitrate, sulfate, Fe, Cu, Pb and Zn in the sediment than in the control area. Accordingly, special attention should be paid to the ecological risk of heavy metals in sediments and plants in river eco-remediation projects especially in rivers polluted by heavy metals, although the metals were lower than the level of considerable ecological risk in this study.
为了研究生态修复对河水和底泥中营养物质和重金属的影响，在中国的一条城市河流中，对一个为期 2 年的主要采用种植浮床系统的生态修复场地进行了野外研究。在修复之前，待修复区域的水和底泥的测试性能与对照区域没有区别，只是河水的化学需氧量（COD）和总氮（TN）浓度较高。修复后，修复区域显示出有效去除了河流中的营养物质，提高了溶解氧和透明度。与对照区域相比，经过 2 年的修复，修复区域河水的硝酸盐浓度更高，而 COD、铵、Mn 和六价 Cr 的浓度更低。修复区域的底泥中有机碳、TN、硝酸盐、硫酸盐、Fe、Cu、Pb 和 Zn 的浓度也高于对照区域。因此，尽管在这项研究中这些金属低于具有相当生态风险的水平，但在河流生态修复项目中，特别是在受到重金属污染的河流中，应特别注意底泥和植物中重金属的生态风险。
