凤眼莲在城市重污染河道修复中的应用

外港河是秦淮河重要支流，长期以来遭受严重污染。2006年4月份起对外港河进行了综合生态治理。在前期清淤和截污的基础上，7月份开始引种凤眼莲。在上游排污口附近和外港河河口段分别设置的4个生态区以及河面上布设的水面载体内全面放养以凤眼莲为主的浮水植物。经过5个多月的初步治理，外港河水体透明度从40cm以下提高到120cm左右，COD下降了70．4％，TSS、TN和NH3-N分别下降了39．6％、49．7％和21．8％。结果证明，凤眼莲在净化严重污染的河道方面起到了良好的效果，引种凤眼莲治理城市重污染河道是切实可行的；此外，用PVC管设计制作的水面载体来放养浮水植物可以点缀水面环境，美化城市河道景观。

Application of water hyacinth in restoration of heavily polluted urban rivers

Waigang River is one of major anabranches of Qinhuai River and has suffered long-time heavily pollution. The ecological restoration was performed from April 2006. After cleaning sediments and intercepting effluent, water hyacinth was introduced to Waigang River. Water hyacinth grew freely in the surface artificial carriers and four ecological areas around upriver effluent outlets and estuary. After 5 months primary restoration, water transparency rose from 40 cm to about 120 cm, COD, TSS, TN and NH3-N decreased by 70. 4%, 39.6% , 49.7% and 21.8% , respectively. Our work showed that it is feasible and effective to restore heavily polluted urban river using water hyacinth introduced to the river. In addition, floating plants cultured in surface artificial carriers could make urban river landscape more beautiful.