圆明园景观水体生态修复过程中水质变化的初步研究

Change of water quality during the ecological restoration in the Garden of Yuanmingyuan

摘要:

生态修复技术在水体环境治理中日益受到广泛关注。通过投放食藻虫控藻，提高水体透明度，继而采取以恢复沉水植被为重点的一系列生态修复措施，修复富营养化景观水体的食藻虫控藻引导水域生态修复工程技术得到应用和发展。在以再生水补给条件下，圆明园凤麟洲于2007年9月至11月，方河、鉴碧亭、玉玲珑馆3个景观水体于2008年4月至6月分别实施了食藻虫控藻引导的水域生态修复工程。对生态修复过程中与实施后水质状况进行监测，结果表明，浊度、化学需氧量（COD）、总氮（TN）、总磷（TP）、叶绿素a（Chla）等主要水质指标均有极大改善。修复后，水体浊度仅为1～2NTU，COD为6~11 mg/L，TN为0.28~0.98 mg/L，TP为0.019~0.044 mg/L， Chla为2.1~8.5 mg/m3。与修复前相比，浊度、COD、TN、TP分别下降了74%~99%、63%~87%、77%~85%、77%~85%，水质从V-劣V类改善为II-Ⅲ类。

Abstract:

Ecological restoration of water environment is in the increasingly widespread concern. Aquatic ecological restoration engineering technology guided by algaeeating daphnia controlling algae was applied to improve water clarity by input algae-eating daphnia, then taking such planting submerged aquatic vegetation as the focus of a series of ecological restoration measures to rehabilitate eutrophication landscape water. In reclaimed water supply conditions, the landscape waterbodies of the Yuanmingyuan implementation projects of aquatic ecological restoration were guided by algaeeating daphnia controlling algae. In Fanghe, Jianbiting, and Yulinglongguan during April to June 2008, and Fenglingzhou during September to November, 2007, water quality monitoring was carried out during and after the restoration. The result indicates that the main indexes such as turbidity, COD, TN, TP and Chla were improved greatly. After restoration, they were 1-2NTU, 6-11 mg/L, 0.28-0.98 mg/L, 0.019-0.044 mg/L, 2.1-8.5 mg/m3 respectively. Compared with before the restoration, the four indicators mentioned above decreased 74%-99%, 63%-87%, 77%-85%, 77%-85% respectively, and the water quality was II-III grade compared with V grade before restoration.