垂直流人工湿地是一种高效的污水生态处理系统，它在生活污水、农业面源以及污水厂尾水深度处理中都具有广阔的应用前景。但是目前国内外对其净化COD的机理与影响因素及运行参数调控优化等缺乏深入研究，从而影响了其处理效能的发挥。本申请从基质、植物、微生物和运行参数出发，拟采用人工土柱、微宇宙和小型人工湿地相结合的研究方法，弄清垂直流湿地基质的物理、化学和微生物作用以及植物、微生物及其联合作用在COD去除中的贡献大小，揭示基质、植物、微生物三因素在COD去除中的作用机理；探讨单因素和多因素（HRT、水力或污染负荷、水位）组合方案对COD去除效果的影响规律，获得COD去除效果最佳的单因素参数值和运行参数组合方案等调控措施；优化微生物的代谢作用，确定最优条件下湿地微生物群落结构；弄清COD去除与土壤有机质积累的关系，建立COD去除与有机质积累的生态动力学模型，为提高垂直流人工湿地COD去除效果提供理论依据

Vertical-flow constructed wetland, as an efficient ecological system of sewage treatment, had wide application prospects in advanced treatment of domestic sewage, agriculture nonpoint and wastewater from sewage treatment plant. Although there were numerous research achievements on vertical-flow constructed wetland in domestic and overseas, including purification mechanism of COD, influence factors, optimization and control of operation parameters, it was not further enough to maximize its treatment effectiveness. This application intended to adopt such methods as artificial soil column, microcosm combined with small-scale constructed wetland, based on matrix, plants and microbes, which could be used to weigh the contribution of vertical-flow constructed wetland in COD removal, especially in physical, chemical and microbes effects of matrix, as well as combined effects of plants and microbes. The objectives we need to make clear respectively are revealing the effectiveness mechanism of matrix, plants and microbes in COD removal; discussing the effectiveness discipline of single-factor and multi-factor(HRT, hydraulic or pollution load, the water level)and obtaining the optimized single-factor parameters and operation parameters with combination scheme in COD removal; optimizing metabolism of microbes and ensure the microbial community structure of wetlands in the best condition; making it clear that the connection between COD removal and soil organic matter accumulation and ecological dynamic model of them, so that we could provide theoretical basis for how to improve COD removal effects of vertical-flow constructed wetland.