千屈菜生态浮床与凤眼莲对养殖水体净化的比较研究

Comparative Study of Purification Capacity in Aquaculture Water Between Lythrum salicaria and Eichhornia crassipes

为考查千屈菜生态浮床在水产养殖水体净化中的作用,将9个相同体积的人工养殖锦鲤水泥池分为3组,分别作为对照组(不栽培植物)、千屈菜组(设置千屈菜生态浮床)和凤眼莲组(种植相同生物量的凤眼莲),在相同的养殖条件下,进行为期60d的实验.其间,每间隔12d取水样,检测水体中总氮、氨态氮、硝酸盐氮、亚硝酸盐氮、总磷、化学需氧量(CODCr)和叶绿素a含量等指标,并对三组水体的以上指标进行比较.结果显示:实验过程中千屈菜组硝酸盐氮含量显著高于对照组和凤眼莲组(P<0.05);对照组与两实验组其他水质指标无显著差异(P>0.05);亚硝酸盐氮含量和CODCr值千屈菜组<对照组<凤眼莲组.有关利用千屈菜生态浮床净化水产养殖水体时的合理种植密度、种植时间及其生理变化与净水效果之间的关系等尚有待深入研究.

To investigate the purification capacity of Lythrum salicariain aquaculture water,nine cement ponds in the same size used for culturing Cyprinus carpio were randomly divided into control group（no plant）,Lythrum salicaria group（with Lythrum salicaria ecological floating bed）and Eichhornia crassipes group（planting Eichhornia crassipes withthe same amount of biomass）and reared under the same prescribed conditions for 60 days,respectively.Every 13 days sample water was taken from each pond to test the content of the total nitrogen,ammonia nitrogen,nitrate nitrogen,nitrite nitrogen,total phosphorus,chemical oxygen demand（CODCr）and chlorophylla and a comparative study is done between the three.The results indicated that during the experiment significant difference is found in terms of the nitrate content and nitrogen content in Lythrum salicaria compared with the other two groups（P0.05）;No significant difference is found in terms of the other indices between the control group and the two experimental groups（P0.05）;as for the value of the nitrate content and the CODCrcontent,the Lythrum salicaria groupthe control groupEichhornia crassipes group.Further studies remains to be done concerning the proper planting density,planting time,physiological change and purifying efficiency in the use of Lythrum salicaria biological floating bed to clarify the aquaculture water.