大清河流域河岸植被带污染物净化能力研究

Study on Pollutant Purification Capacity of Riparian Vegetation Zone in Daqing River Basin

为了解决白洋淀上游河岸带植被类型单一、生态功能低下等问题,从河岸植被带截留、净化面源污染物的生态功能定位出发,选取2种草本和1种灌木为研究对象,通过模拟径流冲刷试验,研究河岸植被带对氮、磷及泥沙污染物的净化效果。结果表明:(1)与单一灌木相比,单一草本的净化效率更好,狗牙根(Cynodon dactylon)的总磷、总氮和泥沙的净化效率最佳,分别为10.88%,6.96%,34.20%;黑麦草(Lolium perenne)对氨氮和硝氮有较好的净化效果,分别为10.11%和9.54%;(2)在多组植物组中,胡枝子(Lespedeza bicolor)、狗牙根、黑麦草的草灌组合净化效率较好,在各项指标平均值上分别较裸土组提高了13.31%,10.84%,9.64%,12.36%,46.43%;(3)灌草和混草的植物组合对5项污染物指标的净化效率均较高,混植组的去除效果优于单一植物组。河岸植被带对面源污染有着一定的净化效果,其中灌草和混草组合的净化效果较好,胡枝子、狗牙根、黑麦草的草灌植物组合表现出最好的净化效果。

In order to solve the problems of single vegetation type and low ecological function in the riparian zone in the upper reaches of Baiyangdian Lake, starting from the ecological function orientation of intercepting and purifying non-point source pollutants in the riparian vegetation zone, two kinds of herbs and one kind of shrub were selected as the research object to study the purification effect of riparian vegetation zone on nitrogen, phosphorus and sediment pollutants through a simulated runoff scouring test. The results were as follows:(1) Compared with single shrub, the purification efficiency of single herb was better, and the purification efficiency of total phosphorus, total nitrogen and sediment of Cynodon dactylon was the best, which were 10.88%, 6.96% and 34.20% respectively;Lolium perenne had good purification effects on ammonia nitrogen and nitrate nitrogen, which were 10.11% and 9.54% respectively;(2) Among the multiple plant configurations, the purification efficiency of grass shrub combination of Lespedeza bicolor, Cynodon dactylon and Lolium perenne was better, and the average values of various indexes were increased by 13.31%, 10.84%, 9.64%, 12.36% and 46.43% respectively compared with the bare soil;(3) The plant combination of shrub&herbs and mixed herbs had higher purification efficiency for five pollutant indexes, and the removal effect of mixed plant group was better than that of single plant group. In conclusion, riparian vegetation zone had purification effect on surface source pollution, among which the combination of shrub&herbs and mixed herbs had a better purification effect. The combination of grass and shrub plants of Lespedeza bicolor, Cynodon dactylon and Lolium perenne showed the best purification effect.