组合型生态浮床对水体修复及植物氮磷吸收能力研究

在天鹅湖水体中构建以水生植物和陆生喜水植物为实验植物,浮法控制器、水循环增氧系统和造浪-输送系统相集合的组合型生态浮床。在中试研究中,研究了其对天鹅湖上覆水和沉积物中营养物质的修复动态。结果表明,经过4个多月的组合型生态浮床生态修复,天鹅湖上覆水中TN、NH4+-N和TP的去除率分别达到61.92%、63.09%和80.0%,沉积物中TN和NH4+-N含量的去除率分别达到23.79%和37.04%,TP含量升高了43.71%;组合型生态浮床的5种浮床植物的氮磷累积量差异显著,再力花和美人蕉对氮磷的吸收速率显著高于菖蒲、薄荷和水稻,再力花和美人蕉对氮的吸收速率达到12.19 g/(m2.d)和7.90 g/(m2.d),对磷吸收分别达到0.81 g/(m2.d)和0.99 g/(m2.d)。美人蕉和再力花对氮磷的吸收量均是茎叶>根系,其中美人蕉茎叶氮、磷吸收量分别为根系的2.73倍和1.93倍,再力花分别为1.83倍和1.19倍,通过浮床系统植物水上部分的收割可以去除水体中的氮磷。

Study on water remediation and uptake ability of nitrogen and phosphorus by plants using combined ecological floating bed

A new type of combined ecological floating bed (CEFD) was developed in our study, which combined aquatic plants, hydrophilous plants and ancillary equipments that include floating controllers, water-cycling aerator systems and wave-making systems. The pilot study on remediation of the overlying water and the sediment of Swan Lake was carried out. Results showed that the removal efficiencies of TN, NH₄⁺-N and TP were 61.92%, 63.09% and 80.0%, respectively in overlying water, while the removal efficiencies of TN and NH₄⁺-N were 23.79% and 37.04%, respectively, and the concentration of TP increased by 43.71% in sediment after more than 4 months operation of the CEFD. The differences of accumulation of nitrogen (N) and phosphorus (P) in the 5 kinds of floating-bed plants were significant. The uptake rates of Thalia dealbata and Canna indica were higher than that of Acorus tatarinowii Schott, Herba menthae and O. Sativa L. The N uptake rates of Thalia dealbata and Canna indica were 12.19 g/(m²·d) and 7.90 g/(m²·d) with 0.81 g/(m²·d) and 0.99 g/(m²·d) to the P uptake rate respectively. The N and P uptake amounts in stems/leaves of Thalia dealbata and Canna indica were greater than that in roots. The ratios between stems/leaves and roots of N, P content were 2.73 and 1.93 in Canna indica respectively, while that were 1.83 and 1.19 in Thalia dealbata. Thus, the N and P in stems/leaves of floating-bed plants could be removed by reaping.