运行方式对潜流人工湿地氧分布及脱氮的影响

Effect of Operation Modes of Subsurface Flow Constructed Wetlands for Spatial Distribution of Dissolved Oxygen and Nitrogen Removal

为了探究运行方式对水平潜流人工湿地脱氮效率的影响,分别采用了连续运行和不同落干时间的间歇运行方式处理生活污水。通过对比分析各方式下湿地床体溶解氧的空间分布来揭示脱氮效果差异。结果表明,间歇运行方式对湿地床体中上层有较明显复氧作用,落干时间的延长可以增强复氧效果;间歇运行方式下湿地的硝化和反硝化能力均要强于连续运行方式,其中硝化反应强度随着湿地氧环境的改善而提高,总氮的去除率与硝化反应强度呈正相关关系,但是间歇运行不同落干时间下反硝化能力没有显著差异,硝化反应强度是水平潜流人工湿地脱氮的限制因素。

To explore influence of operation modes on nitrogen removal efficiency in horizontal subsurface flow constructed wetland, continuous-flow and batch flow operation modes with different drain times were applied to treat domestic wastewater. Comparative study for spatial distribution of dissolved oxygen under each operation mode was done to reveal the difference of nitrogen removal efficiency. Results indicated that batch flow operation had a high oxygen supply within the upper layer and longer drain time made the effect more apparently. Nitrification and denitrification intensity of batch flow operation were both stronger than the continuous flow, and that the nitrification intensity was enhanced in a more oxidized condition, closely correlative with total nitrogen removal efficiency. Results also indicated no significant difference in denitrification intensity between different drain times, thereby nitrification intensity is the limiting factor of nitrogen removal in horizontal subsurface flow constructed wetlands.