大莲湖生态修复工程对水质影响的研究

大莲湖是淀山湖水系中富营养化程度较为严重的湖泊,从2008年12月起,为了改善水质,重建大莲湖生态环境,采取了塑造地型、设计护坡、调整水系、配置植物、构建快速渗透系统等措施治理大莲湖,分析了生态工程完工后半年多来大莲湖水质变化状况;结果表明:经过生态修复后,其水质得到明显改善,COD、总氮和总磷分别比生态区外的鱼塘下降了68%、62%和74%;氨氮平均为0.27 mg/L,亚硝态氮平均0.02 mg/L,叶绿素a平均下降了72%。因此,将工程措施与生物净化方法有机结合在一起,并因地制宜地构建快速渗透系统是湖泊治理的一条有效途径,该修复工程的成功实施也为其他生态修复工程提供了技术支持。

Studies on effects of ecological restoration on water quality in Dalian Lake

Dalian Lake is an eutrophic shallow lake in Dianshan area in Shanghai. Several ecological restoration measures have been carried out since December 2008 to improve its water quality and restore the surrounding ecosystem. The measures include shaping the physiognomy, designing revetments, dredging the water system structure, configuring plants and building speediness-filter systems. Water quality improved significantly after six months of cultivation and operation. Mean concentrations of COD, TN, TP and Chl-a reduced by 68%, 62%, 74% and 72%, respectively, compared to that of water outside the ecological area. Mean concentrations of NH₃-N and NO^-₂-N were 0.27 mg/L and 0.02 mg/L, respectively. The results indicated that it was efficient to improve lake ecosystems with the engineering measures, biological purification methods and speediness filter systems combined. The implementation of this project provides technical supports for other similar lake restoration constructions.