挺水植物浮床对再生水补水景观水体的修复

Reclaimed Landscape Water Restoration by Emergent Plants in Floating Bed

随着城市水资源短缺现象愈发严重,再生水成为景观水体的重要补水来源。然而再生水所含营养盐浓度普遍高于受纳水体,导致再生水补水景观水体易出现水体富营养化现象。该文利用浮床技术种植4种挺水植物:美人蕉、鸢尾、千屈菜、旱伞草,通过4种植物伸展于水中根部对营养盐的吸收以及其浮床上植株体对营养盐的积累作用,将水体中的氮磷等营养盐迁移转化至植物体内,并以定期收割植物的方式将其与水体分离。通过植物修复,水体水质由Ⅴ类提高到Ⅳ类,除TN外其余指标达到Ⅱ类。水体中TP浓度从0.25 mg/L下降到0.05 mg/L,TN浓度略有下降,保持在0.5 mg/L,浊度由90 NTU降到10 NTU以下,叶绿素含量由原来的10 mg/m^3降低到1 mg/m^3左右。实验结果表明,植物修复能够有效地改善已呈现富营养化的再生水景观水体。

Due to water shortage, reclaimed water becomes an important supplement of landscape pond in city. With higher content of nutrient in reclaimed water compared with surface water, eutrophication occur easily in Landscape water. Four emergent plants: Canna indica L, Iris tectorums, Lythrum salicaria L., Cyperus alternifolius, were planted in floating bed in this study. Through uptake by plant roots and accumulation by plant tissue of nutrient, it had succeeded transforming nutrient from water to element plant growth needed. After phytoremediation, water quality increased from Ⅳ to Ⅱ level. TP concentration in water decreased from 0.25 mg/L to 0.05 mg/L. TN concentrations declined slightly, keeping around 0.5 mg/L. Turbidity dropped from 90 NTU to below 10 NTU. And Chlorophyll content decreased from original 10 mg/m^3 to 1 mg/m^3. The results showed that phytoremediation can effectively improve eutrophic landscape water-body.