不同基质复合垂直流人工湿地对富营养化景观水的净化效果

研究了两套不同基质复合垂直流人工湿地小试装置在不同季节对富营养化景观水的净化效果,分析了温度变化对污染物去除效果的影响,考察了微生物的硝化强度和反硝化强度以及基质理化性质对植物生长状况的影响,并探讨了氮、磷的去除途径.结果表明:不同基质复合垂直流人工湿地随季节变化对浊度、COD和磷的去除效果差异不明显;温度降低对脱氮效果影响显著,对磷的去除影响不大.沸石-页岩湿地硝化强度和反硝化强度优于砾石湿地.采用沸石作为基质可以提高系统对氮的去除效率,促进湿地植物的生长.对氮、磷去除途径的分析表明:微生物的硝化反硝化作用以及基质对磷的吸附沉淀作用是复合垂直流人工湿地去除氮、磷的主要途径;植物吸收分别占湿地TN、TP去除量的16%和35%左右,也是个重要途径.

Effect of the substrate on purification of eutrophic scenic water in integrated vertical-flow constructed wetlands

Seasonal performance of two integrated vertical-flow constructed wetlands(IVFCWs)filled with different substrates in treating eutrophic scenic water was investigated focusing on the impact of water temperature.The wetland's capacities for nitrification and denitrification,the effects of the substrate properties on the plant growth,and the mechanisms for removal of N and P species were also studied.The ambient temperature had little effect on the removal rates for turbidity,COD and phosphorus species in both IVFCWs.Declining water temperature caused a reduction in the removal of nitrogen species but no notable changes in phosphorus removal.The CWs filled with zeolite-shale exhibited greater capacities for nitrification and denitrification than the CWs filled with gravel.Zeolite increased the nitrogen removal rate and stimulated the plant growth.The primary mechanisms for nitrogen removal were nitrification and denitrification;the mechanisms for phosphorus removal were adsorption and sedimentation.As the secondary removal mechanism,the plant uptake accounted for about 16% of TN and 35% of TP of the feed.