可调式沉水植被网床对泥沙型富营养化河道生态修复工程研究

分别采用水花生(Alternanthera philoxeroides (Mart.) Griseb)和狐尾藻(Myriophyllum verticillatum)2种可调式沉水植被网床对临港新城环湖流动泥沙型河道进行修复, 通过4个月连续跟踪测定修复河道总氮(TN)、硝态氮(NO₃-N)、亚硝态氮(NO₂-N)、总磷(TP)、活性磷酸盐(PO₄-P)的含量变化以及水体透明度(SD)变化以评价可调式沉水植物网床生态修复效果。结果显示, 沉水植物网床对流动泥沙型河道透明度具有明显改善作用。其中, 水花生网床和狐尾藻网床对TN、NO₃-N、NO₂-N、TP、PO₄-P的削减率分别为69.58%、67.91%、84.48%、62.26%、82.61%和45.48%、58.32%、76.56%、43.12%、73.68%, 且分别对泥沙型河道透明度提高了18%和26%。可见, 水花生网床对营养盐的削减效果优于狐尾藻网床, 而狐尾藻网床对透明度改善效果优于水花生网床。因此把这2种可调式沉水植物网床结合起来, 对流动泥沙型富营养化河道具有更好去除富营养物及泥沙的生态修复效果。

Bioremediation of sediment typed eutrophic river with adjustable submerged vegetation net-beds technology

The flowing sediment typed river water in the Lingang New City, Shanghai was restored with the continuous adjustable Alternanthera philoxeroides and Myriophyllum verticillatum submerged vegetation net beds. The bioremediation efficiency was evaluated by 4-month continuous monitoring of total nitrogen(TN), nitrite nitrogen(NO₂-N), nitrate nitrogen(NO₃-N), total phosphorus(TP), phosphate(PO4-P) and Secchi depth(SD) from June to December in 2011. The results showed that the transparency and water quality of the eutrophic sediment typed river were improved significantly. The TN, NO₂-N, NO₃-N, TP, PO₄-P concentrations of the eutrophicate water were decreased by 69.58%, 67.91%, 84.48%, 62.26%, 82.61% and 45.48%, 58.32%, 76.56%, 43.12%, 73.68%, respectively with Alternanthera philoxeroides and Myriophyllum verticillatum submerged vegetation net beds. The transparency of sediment typed river water was increased by 18% and 26%, respectively with Alternanthera philoxeroides and Myriophyllum verticillatum submerged vegetation net beds. It indicated that Alternanthera philoxeroides submerged vegetation net bed was better than Myriophyllum verticillatum submerged vegetation net bed in reducing nutrient. While Myriophyllum verticillatum submerged vegetation net bed was better than Alternanthera philoxeroides submerged vegetation net bed in increasing transparency of the sediment typed river water. So combining both Myriophyllum verticillatum and Alternanthera philoxeroides submerged vegetation net beds would increase bioremediation efficiency for removing nutrients and sediment in rivers.