The concentrations of NH3-N, BOD5 and TP in net bag decreased by 15.6%, 28.5% and 7.5% respectively in comparison with control site. Hydrodictyon can be applied to purify source water in winter as ecological-engineering measure.

• 与对照测点比较；网袋内氨氮、生化需氧量和总磷的浓度分别下降了15.；6%25、28