3种景观植物对城市河道污染水体的净化效果

Purification Effect of Nitrogen and Phosphorus in Polluted Water of Urban Rivers by Three Landscape Plants

以美人蕉、绿萝、马丽安3种景观植物为试材,制成生态浮床,研究3种植物以及无植物浮床对城市污染水体中氮、磷的净化效果,试验共持续46d.结果表明:3种植物在污染水体中能保持较强的生命力,试验结束时,其株高、根长及生物量均有显著增加,增长率表现为美人蕉>马丽安>绿萝;美人蕉、绿萝、马丽安对水体中TN的去除率分别为93.95%,90.25%和92.60%,远高于对照组的去除率(60.44%);3种植物对水体中NH4+-N的去除率分别为98.06%,95.07%和97.61%,其中美人蕉、绿萝组NH4+-N的主要去除途径为硝化反应,马丽安组NH4+-N去除主要是通过氨挥发以及硝化反应等,而对照组NH4+-N去除率(81.62%)较高的主要原因为氨的挥发;美人蕉、绿萝组ρ(NO3--N)呈先增加后减少的趋势,而马丽安和对照组ρ(NO3--N)增幅不大,各试验组ρ(NO3--N)变化与水体硝化、反硝化反应以及植物吸收有关;3种植物对水体中TP和CODMn均有明显的去除效果,去除率显著大于对照组.试验表明,3种植物对污染水体均有很好的净化效果和一定的景观价值,可作为城市河道污染水体治理的优良物种而推广使用.

Three kinds of ecological floating beds were made of Canna indica, Aglaonema modestum and Scindapsus aureus, respectively, to study their effects on removing nitrogen and phosphorus from wastewater. The experiment lasted 46 days. The results indicated that three landscape plants were adaptable to grow in the urban river, and their biomass, height and root significantly increased at the end of experiment. The increasing rate was Canna indica 〉 Aglaonema modestum 〉 Scindapsus aureus . The removal rates of N by Canna indica , Scindapsus aureus and Aglaonema modestum were 93.95%, 90.25%, 92.60%, respectively, all of which were higher than the control （60.44%）. The removal rates of NH^4＋ -N were 98.06%, 95.07%, 97.61%, respectively. NH4^＋ -N removal by Canna indica and Scindapsus aureus was through nitrification, while in Aglaonema modestum it was through NH3 volatilization. In the control treatment, NH4^＋ -N removal was through NH3 volatilization, and reached 81.62% . NO3^- -N concentration had the tendency first to increase and later to decrease in the Canna indica and Scindapsus aureus treatments, but was slightly different in the Aglaonema modestum and control treatments. This related to the nitrification, denitrification and plant adsorption. Three plants had good removal effects on the total phosphorus and CODMn, which were higher than the control treatment. Based on their good effects on nitrogen and phosphorus removal, three landscape plants are recommended as species of aquatic vegetation in phytoremediation of wastewater of urban river.