潮汐流-潜流组合人工湿地污水净化效率

构建了潮汐流-潜流组合和潜流-潮汐流组合人工湿地对污水进行处理，分别研究2种组合人工湿地对污水的净化效果。结果表明，在平均进水COD浓度为214．28mg／L、NH4＋-N浓度为10．57mg／L、PO34--P浓度为5．44mg／L、TN浓度为10．25mg／L，水力负荷为o．2m3／（m2·d）的条件下，潮汐流-潜流组合人工湿地对COD、PO34--P的去除率分别为58．28％和46．99％，与潜流-潮汐流组合人工湿地处理效果相近；对NH4＋-N、TN，潮汐流-潜流组合人工湿地的去除率分别为69．93％和71．03％，比潜流-潮汐流组合人工湿地分别高15％和33％。潮汐流-潜流人工湿地的组合，在系统内实现了硝化-反硝化的组合，强化了系统对TN的净化效果，其对TN的净化效果比-般的潜流和表面流人工湿地组合提高20％～30％。总体上，潮汐流-潜流组合人工湿地具有更好的净化效果。

Sewage purification effect of tidal flow-subsurface flow hybrid constructed wetland

The tidal flow-subsurface flow and subsurface flow-tidal flow constructed wetland systems were built and studied, respectively, for sewage treatment. The results showed that when the average inflow concentra- tions of COD, NH4 -N, PO34- -P and TN were 214.28, 10.57, 5.44 and 10.25 mg/L, respectively, and the hy- draulic loading was 0.2 m3/（ m2. d） , the corresponding removal efficiencies of COD and pO34- -P by tidal flow- subsurface flow wetland were 58.28% and 46.99% , respectively, which was similar to those of subsurface flow- tidal flow constructed wetland. In contrast, the removal rates of NH4＋ -N and TN by tidal flow-subsurface flow hy- brid constructed wetland were higher （69.93% and 71.03% ） than those of subsurface flow- tidal flow hybrid constructed wetland. The higher removal efficiency is due to the concurrent occurrence of nitrification-denitrifica- tion in tidal flow-subsurface flow hybrid constructed wetland system, thus enhancing the purification efficiency of TN, even 20% to 30% higher than those by the general hybrid constructed wetland of subsurface flow and free water surface flow system. In comparison with the subsurface flow-tidal flow system, tidal flow-subsurface flow hybrid constructed wetland exhibited a better performance for sewage purification.