3种植物对养殖水体中氮磷净化作用研究

N and P Purification in Aquatic Water with Three Plants

为研究养殖水体中适于净化氮磷的植物,选择凤眼莲(Eichhornia crassipes)、紫背浮萍(Spirodela polyrrhiza)、空心菜(Ipomoea aquatica)等3种植物为试验对象。通过对每种植物设定生物量梯度,每5天取1次水样,测定分析养殖水体的总氮(TN)、硝酸盐(NO3-)、亚硝酸盐(NO2-)、氨氮(NH4+-N)和总磷(TP)等氮磷指标,进行不同植物、生物量梯度以及试验时间对养殖水体氮磷净化效果的研究。结果显示,3种植物均正常生长,对养殖水体氮磷均有较好净化能力。3种植物对氮净化效果较好的时间在10~15天,对磷的净化效果较好的时间则在15~20天。凤眼莲生物量2000~2500 g/m3,浮萍生物量150~200 g/m3,空心菜生物量800~1600 g/m3对氮磷的净化效果最佳。3种植物均可用于养殖水体的氮磷净化,3种植物对养殖水体中TN、TP、NO3-去除效果空心菜>浮萍>凤眼莲,对NO2-、NH4+-N去除效果凤眼莲>空心菜>浮萍。凤眼莲更适于养殖水体的氮磷净化。

To study the suitable plants for N and P purification in aquatic water,Eichhornia crassipes,Spirodela polyrrhiza and Ipomoea aquatica were selected as test subjects.The biomass gradients were set up.The water samples were taken once every 5 days.The indexes of N and P such as TN,NO3-,NO2-,NH4+-N and TP in aquatic water were determined and analyzed.The effects of different plants,biomass gradients and experimental time on N and P purification were studied.The results showed that the three plants grew normally and had good purification capacity for N and P in aquatic water.The three plants had better effect on N purification in 10-15 days,and on P purification in 15-20 days.The biomass of Eichhornia crassipes,Spirodela polyrrhiza and Ipomoea aquatica with the best purification effect on N and P was 2000-2500 g/m3,150-200 g/m3 and 800-1600 g/m3,respectively.All the three kinds of plants can be used to purify N and P of aquatic water,the order of the purification effect on TN,TP,NO3-was Ipomoea aquatica>Spirodela polyrrhiza>Eichhornia crassipes,while on NO2-、NH4+-N was Eichhornia crassipes>Ipomoea aquatica>Spirodela polyrrhiza.Eichhornia crassipes is more suitable for the purification of N and P in aquatic water.