连续可调式沉水植物网床对河道水质的修复

在太湖贡湖水源保护区陆域的一条长约200 m的污染河道内构建了一系列连续可调式沉水植物网床,形成了以菊花草、苦草、伊乐藻、轮叶黑藻和菹草等沉水植物构成的水生植物群落；跟踪监测了总氮(TN)、铵态氮(NH4 +-N)、亚硝态氮(NO2--N)、硝态氮(NO3--N)、总磷(TP)和磷酸盐(PO43--P)等水质指标,分析沉水植物网床引导沉水植被恢复对污染河道的水质修复效果.结果表明:沉水植被网床构建后,水体透明度显著升高,由修复前的0.5m提高到1.7 ～1.8 m;在沉水植被网床构建后的第5天和第20天,TN和TP的削减率分别为35.6％、66.3％和29.4％、63.2％；5个月后,修复河道水体内NH4+-N、NO2--N、NO3--N、TN、PO43--p和TP的浓度比对照组显著降低,削减率分别达到92.4％、76.8％、72.7％、73.9％、90.5％和92.0％.由连续可调式沉水植被网床引导恢复的水生植物群落可用于河道,特别是陆域浅水污染水体的生态修复.

Bioremediation of river water quality by consecutively adjustable submerged vegetation net

A series of consecutively adjustable submerged vegetation nets were constructed in a polluted shallow river with a length of about 200 m and nearby the water resource protection area of Taihu Lake in East China,forming an aquatic vegetation consisted of submerged plant species Cabomba caroliniana,Vallisneria natans,Elodea nuttallii,Hydrilla verticillata,and Potamogeton crispus.The water quality indices including total nitrogen(TN),ammonium nitrogen(NH4+-N),nitrite nitrogen(NO2--N),nitrate nitrogen(NO3--N),total phosphorus(TP),and phosphate(PO43--P) were monitored,and the bioremediation effect of the vegetation nets was evaluated.After setting up the vegetation nets,the Secchi depth(SD) of the river changed from 0.5 m to 1.7-1.8 m,and the TN and TP concentrations 15 and 20 days after the nets constructed decreased by 35.6% and 66.3%,and 29.4% and 63.2%,respectively.After five months,the concentrations of NH4+-N,NO2--N,NO3--N,TN,TP,and PO43--P decreased by 92.4%,76.8%,72.7%,73.9%,90.5%,and 92.0%,respectively.This study showed that consecutively adjustable submerged vegetation net could be a potential approach for treating polluted river waters,particularly for the bioremediation of polluted small landscape shallow water bodies.