不同运行模式人工湿地中溶解氧与净化效率的关系研究

目的]研究不同运行模式人工湿地中溶解氧与净化效率的关系。方法]采用在线试验模型和现场监测分析方法,研究不同运行模式的有/无植物人工湿地对污水的净化效果与溶解氧的关系。结果]连续运行的人工湿地上有无植物对有机物和氮磷污染物的净化效果没有明显影响,间隔运行的人工湿地上有无植物对污水中CODCr、NH4+-N、TN的平均去除率存在显著性差异,种有植物间隔运行的人工湿地对CODCr、NH4+-N、TN的平均去除率比连续运行的人工湿地和没有种植植物间隔运行的人工湿地高。人工湿地系统对污水中CODCr、NH4+-N、TN的净化效率在昼间较高、夜间较低,污染物净化效果与溶解氧之间存在着正相关的关系。人工湿地的前置单元增氧有利于改善后置湿地单元的溶氧环境条件,可以提高人工湿地系统净化污染物的能力。种植植物的人工湿地系统宜在昼间运行,利用好植物的光合增氧潜力,则可表现出良好的净化污染物的效果。结论]该研究为氧化塘-人工湿地系统的运行管理提供了科学依据。

Study on Relationship between Dissolved Oxygen and Purification Efficiency in Constructed Wetlands with Different Operation Modes

Objective] The research aimed to study on relationship between dissolved oxygen and purification efficiency in constructed wetlands with different operation modes.Method] By using online test model and on-site monitoring,relationship between dissolved oxygen and purification efficiency in constructed wetlands with different operation modes was studied.Result] Purification effect of the pollutants had no significant difference by continuous operation of the constructed wetland with plant or without plant.For average removal rates of the CODCr,NH4+-N and TN in sewage,uncontinuous operation of the constructed wetland had significant difference between with and without plant.Average removal rates of the CODCr,NH4+-N and TN by uncontinuous operation of the constructed wetland with plant were higher than that by continuous operation of the constructed wetland and uncontinuous operation of the constructed wetland without plant.Purification efficiencies of the CODCr,NH4+-N and TN in sewage by constructed wetland were higher at daytime and lower at night.Purification effect of the pollutants had positive correction with dissolved oxygen.Oxygenation of the front unit was favorable for improving dissolved oxygen environment in rear wetland unit,and purification capability of the constructed wetland on pollutants could be improved.Constructed wetland with plant should be run in the daytime.When using plant photosynthesis well,good purification effect of the constructed wetland on pollutants could be showed.Conclusion] The research provided scientific basis for operation management of the oxidation pond-constructed wetland system.