净化富营养化景观水体植物的筛选

Screening of garden plants for purifying eutrophic landscape water

以蜘蛛兰Hymenocallis littoralis、藨草Scirpus triqueter、梭鱼草Pontederia cordata、鸢尾Iris tectorum、香菇草Hydrocotyle vulgaris、水蓑衣Hygrophila salicifolia、苦草Vallisneria natans、黑藻Hydrilla verticillata等8种水生植物为试验对象,研究其生长状况及对富营养化园林景观水体中总氮(TN)、总磷(TP)、化学需氧量(COD)等营养物质的去除效果。结果表明:蜘蛛兰、鸢尾、水蓑衣和苦草生物量有较大增长,藨草、梭鱼草、黑藻生物量有所下降,香菇草在试验结束时已全部死亡;8种水生植物都能在一定程度上净化水体中的营养盐,其中水蓑衣对水体中TN、TP、COD、氨氮(NH4+-N)、色度的去除效果较好,去除率分别为50.3%、25.4%、38.5%、23.5%、27.9%;鸢尾、蜘蛛兰和苦草对TN的去除效果次之,其平均去除率分别为44%、39.1%、37.4%;香菇草的耐污能力较差,试验处理后4 d大部分出现死亡腐烂现象。综合各项指标,水蓑衣、鸢尾可优选作为水体净化的水生植物材料,其次是蜘蛛兰和苦草。

Taking 8 species of aquatic plants including Hymenocallis littoralis, Scirpus triqueter, Pontederia cordata, Irgs tectorum, Hydrocotyle vulgargs, Hygroph^la salicifolia, Vallisneria natans and Hydrilla verticiUata as the test objects, this essay studied the growth status of these aquatic plants and their effects for the removal of nutrients like TN, TP and COD in eutrophication garden water by laboratory simulation. The results showed that H. littoralis, I. tectorum, H. salicifolia and V. natans had good biological growth, while S. triqueter, P. cordata and H. verticillata decreased and all ydrocotyle vulgaris even died at the end. Eight kinds of aquatic plants had good nutrient removal effect to some extent, of which H. salicifolia＇s removal effect of TN, TP, COD, NH4^-N and chroma in the garden water was the best with the removal rates reaching 50.3%, 25.4%, 38.5%, 23.5% and 27.9%, respectively. The removal rates of I. tectorum, H. littoralisofand V. natans for TN was 44%, 39.1%, and 37.4%, respectively, which took the second place in the removal effect. H. vulgaris had poor tolerance against pollution, and most died at the 4th day of the test. By comprehensive indicators, H. Salicifolia and I. tectorum can be the first choice of aquatic plants for water body purification, followed by H. littoralis and V. natans.