卵砾石生态河床对河流水质净化和生态修复的效果

为研究卵砾石生态河床在河流原位水质净化和生态修复中的效果,选择位于宜兴市大浦镇的林庄港作为试验河道进行原位观测,对比分析了卵砾石生态河床河段和自然河床河段中的生源要素变化规律和水生生物生长状况。试验结果表明:卵砾石生态河床河段对污染物质的截留效果明显好于自然河床河段,对氨氮和总磷的截留率可分别达到37%和25%,卵砾石生态河床的构建可显著提高河道的自净能力;卵砾石生态河床河段水生植被的生长密度和覆盖率均达到良好的水平,大型底栖无脊椎动物在敏感物种数、分类单元数和生物数量密度等方面均优于自然河段的;卵砾石生态河床为水生植物、底栖动物和附着生物等水生生物提供了适宜的栖息环境,对河流生态系统的健康起到了较好的改善作用。

Effects of ecological gavel bed on water quality purification and ecological restoration in streams

To study the effects of ecological gavel bed on water quality purification and ecological restoration in streams,the in-situ water quality and aquatic organisms in Linzhuanggang River of Dapu Town of Yixing City are monitored.The variation rules of biogenesis elements and the growth situations of aquatic organisms between the ecological gavel bed reach and the natural bed reach are compared.The test results show that the retention ability to pollutants by the ecological gavel bed reach is better than that by the natural reach,with the most retention rate of 30% and 25% to NH3-N and TP respectively,and the ecological gavel bed can improve self-purification ability of streams significantly.The density and coverage of aquatic plants in the ecological gravel bed reach are in favorable condition.The sensitive species,taxa,biomass and density of macroinvertebrates in the ecological gravel bed reach are superior to those in the natural reaches.The ecological gavel bed provides suitable habitat environment for aquatic organisms such as aquatic plants,zoobenthos and fouling organisms,and it may improve the health of stream ecosystem.