The mechanisms of bacterial nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) removal in pilot-scale constructed wetlands (CWs) were investigated in the present work. Three types of CWs were assessed: vertical flow (VF), horizontal flow (HF), and surface flow (SF), each with three planting conditions, with either Thalia, Canna or without plants. The results show that construction types affected microbes more than planting conditions. VF CWs promoted the aerobic processing of total N, total P, COD, and NH₃-N, increasing the respective removal efficiencies by 4–19%, 13–32%, 19–29%, and 75–80%, respectively, compared with SF CWs. The relative abundance of nitrifying, denitrifying, methanotrophic and dephosphorized bacteria, and functional genes such as nxrA, nirK, nosZ, mmoX, and phoD were higher in VF CWs. Positive and simple gene networks in VF CWs can effectively reduce the redundancy in functional genes, enhance bacterial function and gene interactions, thus promoting nutrient removal.

在本工作中，研究了中试规模人工湿地（CW）中细菌氮（N），磷（P）和化学需氧量（COD）去除的机理。评估了三种CW：垂直流（VF），水平流（HF）和表面流（SF），每种都具有三种种植条件，有塔利亚（Thalia），美人蕉（Canna）或没有植物。结果表明，建筑类型对微生物的影响大于种植条件。VF CW促进了总氮，总磷，化学需氧量和NH ₃的好氧处理-N，与SF CW相比，分别将去除效率提高了4–19％，13–32％，19–29％和75–80％。VF CW中硝化，反硝化，甲烷氧化和脱磷细菌和功能基因（例如nxrA，nirK，nosZ，mmoX和phoD）的相对丰度较高。VF CW中的阳性和简单基因网络可以有效减少功能基因的冗余，增强细菌功能和基因相互作用，从而促进营养去除。