为研究伊乐藻—螺蛳组合对湖滨湿地的净化效果并探究两者的最优密度搭配，通过不同密度的伊乐藻（100 g/m2, 200 g/m2, 300 g/m2）和螺蛳（120 g/m2, 240 g/m2, 360 g/m2）组合，研究在不同搭配比例条件下，伊乐藻的生长情况、螺蛳的存活率和生长情况。检测了水体中总氮（TN）、总磷（TP）、化学需氧量（COD）、氨氮（NH4+-N）、硝酸盐氮（NO3--N）和亚硝酸盐氮（NO2--N）的质量浓度变化，以及底泥中的TN、TP和COD变化情况。结果显示：伊乐藻—螺蛳组合对水体及底泥中的N、P和COD有很好的去除效果，伊乐藻初始密度为200 g/m2时，净化效率最高。本实验中，各实验组伊乐藻的最终生物量无显著差异，接近于(554.31±29.60)g；螺蛳密度高对COD有更好的去除效果，然而360 g/m2组的密度导致死亡率较高。研究表明：在本实验条件下，伊乐藻200 g/m2，螺蛳240 g/m2是最优密度搭配。

In order to study the effect of Elodea nuttallii-Bellamya aeruginosa combination on lakeside wetland purification and to explore the best combination of density, by combining different density of Elodea nuttallii (100 g/m2, 200 g/m2, 300 g/m2) and Bellamya aeruginosa (120 g/m2, 240 g/m2, 360g/m2), the growth of Elodea nuttallii, the survival rate and growth of Bellamya aeruginosa under the condition of different combination proportions are studied . Mass concentration changes of TN, TP, COD, NH4+-N, NO3--N and NO2--N in water, and changes of TN, TP and COD in bottom mud are tested. The result shows that Elodea nuttallii-Bellamya aeruginosa combination has a great effect on removal of N, P and COD in water and bottom mud. The purification efficiency is the highest when the density of Elodea nuttallii is 200 g/m2. In this study, there is no significant difference in the final biomass (554.31±29.60g) of Elodea nuttallii. Higher density of Bellamya aeruginosa has a better effect on removal of COD, while the density of 360g/m2 causes higher mortality. The study shows that under the condition of this experiment, the best combination of density is Elodea nuttallii: 200 g/m2, Bellamya aeruginosa: 240 g/m2.