表面流人工湿地在滇池湖滨区面源污染控制中的应用研究

在滇池湖滨带核心区退塘还湖措施的基础上,通过对福保村湖滨废弃鱼塘改造,建立了表面流人工湿地系统,对该区域内面源污水处理进行了研究.研究表明,系统年削减入湖污染物COD、TN、TP负荷分别达7 840、650和20 kg,单位面积削减量分别为4 704、390和12 kg·hm~(-2),削减率分别为28.02%、35.93%和4.86%;系统对污水中COD、NH_3-N、TN、TP的去除率分别为15.57%、56.76%、40.37%和35.64%,且除COD外,旱季污染物去除率高于雨季;推流曝气可提高系统对污染物的去除效果,使NH_3-N、TN、TP的去除率分别提高约39%、23%和21%,而COD去除率变化不明显.该系统为滇池湖滨区退塘还湖和湖滨生态系统重建提供了重要的技术示范,对滇池富营养化防治工作的开展具有重要意义.

The Application Study on Surface Constructed Wetlands for Non-Point Source Pollution Control at the Dianchi Lakeshore Region

In this study, we examined the effect of constructed wetlands in former fish ponds along the Lake Dianchi shoreline as an environ-mental protection measure. Abandoned fish-ponds in Fubao Village were used for constructing a surface flow wetland system to treat agricul-tural non-point source runoff in the area. The results indicated that, the total reduction(and reduction per hectare) and reduction rate of COD, TN, TP discharged into the lake were 7 840 kg(4 704 kg·hm~(-2)),650 kg(390 kg·hm~(-2)),20 kg (12 kg·hm~(-2)) and 28.02%, 35.93%, 4.86% respectively. The COD, NH_3-N, TN and TP removal rates in the system were 15.57%, 56.76%, 40.37% and 35.64%, which were higher in the dry season than in the rainy season except for COD. Plug-flow aeration improved the removal performance of the system, with removal rates of NH_3-N, TN, TP enhanced by 39%, 23%, 21% respectively; however, COD removal rate was not enhanced. In short, this study provides an im-portant technical example on implementing the measure of returning ponds to the lake and rebuilding the lakeshore bio-system, both of which are significant to protecting Lake Dianchi.