[组合型生态浮床中各生物单元对污染物去除的贡献及净化机理]生态浮床生物题

　　摘 要：对组合型生态浮床中水生植物单元（空心菜）、水生动物单元（滤食性贝类三角帆蚌）、微生物强化单元（人工介质）进行组合配置，分析不同生物单元的污染物去除贡献率，试验结果表明，组合型生态浮床中人工介质单元对TN、TP、CODMn去除的贡献率分别为48.5%、46.7%、49.9%，均高于水生植物和水生动物单元，人工介质富集的微生物是氮磷等污染物的净化主体，而水生动物单元对Chl-a的去除贡献率达到了79.1%，表明水生动物单元的污染物去除途径主要为三角帆蚌对藻类等颗粒性有机物的滤食。通过三角帆蚌的滤食及排氨作用促进了颗粒有机物的可溶化和无机化，为组合型生态浮床中人工介质上微生物增殖以及植物的吸收提供了有利的基质条件，从而促进了浮床的污染物净化效能。
　　关键词：生态浮床；三角帆蚌；人工介质；贡献率；净化强化；机理
　　中图分类号：X524
　　文献标志码：A
　　文章编号：1674-4764（2012）04-0136-06
　　Contribution and Purification Mechanism of Bio-components to Pollutants Removal in an Integrated Ecological Floating Bed
　　WANG Guofanga， WANG Xiangjinga， WU Leia， LI Xianninga,b
　　(a. School of Energy and Environment；b. Key Laboratory of Environmental Medicine
　　and Engineering, Ministry of Education, Southeast University, Nanjing 210096, P.R.China)
　　Abstract:The aquatic plant (Ipomoea aquatica), aquatic animal (filter-feeding Hyriopsis cumingii), artificial medium for an integrated ecological floating bed (IEFB) were combined, and the contaminant removal rates contributed by different biological units were analyzed. It is shown that, the artificial medium (microorganism) unit acted as the main role of purification of IEFB with approximately 48.5%, 46.7%, and 49.9% of TN, TP and CODMn removed from the water, respectively, much higher than that of aquatic plant unit and aquatic animal unit. Furthermore, the contribution of aquatic animal unit for chlorophyll-a removal was 79.1%, which means that the particulate organic matters filter fed by the Hyriopsis cumingii is the main contaminations removal way of aquatic unit. The filter feeding and ammonia emission effect of the Hyriopsis cumingii promotes the solubilization and mineralization of particulate organic matters, which provides advantaged substance condition for the microorganism attached to the artificial medium of IEFB, and resulting in promoting the purification efficiency of the floating-bed.
　　Key words:ecological floating bed; Hyriopsis cumingii; artificial media; contribution; purifying reinforcement; mechanisms
　　水生植物浮床是用于净化富营养化水体如湖泊、河道的重要生态工程技术之一，具有适用条件宽、充分利用水面进行原位处理、造价低廉且运行管理容易等优点，目前已得到广泛应用［1-2］。但普通水生植物浮床仅种植水生植物，生物要素单一，构成完整生态系统的水生动物及微生物环节较为薄弱，限制了生态功能的发挥，有限的植物生物量也制约了其水质净化效能的进一步提高［3-4］。
　　笔者在普通水生植物浮床的基础上引入了水生动物，并增设了人工介质，构建了由水生植物单元（空心菜）、水生动物单元（三角帆蚌）及微生物强化单元（人工介质）组成的组合型生态浮床。前期研究表明，在水体交换时间为7 d时，组合型生态浮床对TN、NH4+-N、TP、CODMn、Chl-a的平均去除率分别高于普通水生植物浮床15.5%、19.5%、15.1%、20.4%、26.1%，增加水生动物单元与微生物单元可提高浮床对污染物的去除效果，组合型生态浮床对富营养化水体的水质净化具有较好的应用前景。