3种水耕蔬菜对宁夏灌区农田退水中氮磷的净化能力

为更好地保护宁夏湖泊湿地资源,采用生态浮床技术,在实验室内自配富营养化水,模拟宁夏灌区农田退水的基本特征,探讨水芹、生菜、油菜3种水耕蔬菜对宁夏灌区富营养化农田退水中氮、磷的净化能力。结果表明:水芹、生菜及油菜3种水耕蔬菜对水体中氮、磷的吸收效果均较好,能显著降低农田退水中氮、磷的浓度。对总氮的去除率为水芹(79.01%)油菜(70.03%)生菜(67.66%)对照(20.07%);对总磷的去除率为水芹(95.66%)油菜(91.04%)生菜(86.32%)对照(21.70%);对氨氮的去除率为水芹(84.77%)生菜(83.15%)油菜(73.12%)对照(33.51%)。综合来看,水芹的净化能力强于生菜及油菜,在开展宁夏灌区水生植物净化工程中可以着重考虑水芹的应用。

Purifying Capacity of Three Hydroponic Vegetables to Nitrogen and Phosphorus in Farmland Recession Flow in Ningxia Irrigation Area

The purifying capacity of three hydroponic vegetables (cress, lettuce and rape) to nitrogen and phosphorus in recession flow of eutrophication farmland was determined by preparing eutrophication water with the basic characteristics of farmland recession flow in Ningxia irrigation area and the ecological floating raft technique to protect lake and wetland resources in Ningxia.Results: Three tested hydroponic vegetables with the good absorption effect of nitrogen and phosphorus in the water can reduce the concentration of nitrogen and phosphorus in farmland recession flow significantly.The total nitrogen removal rate of cress, rape, lettuce and CK (non hydroponic plant) is 79.01%, 70.03%, 67.66% and 20.07% separately.The total phosphorus removal rate of cress, lettuce, rape and CK is 95.66%, 91.04%, 86.32% and 21.70% respectively.The ammonia nitrogen removal rate of cress, lettuce, rape and CK is 84.77%, 83.15%, 73.12% and 33.51% separately.In conclusion, cress with the better purifying capacity of nitrogen and phosphorus in recession flow of eutrophication farmland should be used in the hydrophyte purification project in Ningxia irrigation area.