The concentration of EN in the water was relative stable and the remove rate of Egeria najas to EN varied consistently especially when at 0.10,0.50,1.00 and 1.50mg/L, namely increased at first and then declined.

• 50 mg/L、1 .；00 mg/L和一somg/L这JL组，即先上升后下降。 对照组和Hg，+浓度为0