两段式沸石多级土壤渗滤系统强化脱氮试验

针对两段式沸石多级土壤渗滤系统(MSL)第2段(缺氧段)反硝化不足的问题,采取分段进水的方式,探讨处理生活污水和受污染河流时,MSL系统的强化脱氮效果.结果表明,在分段进水后,MSL系统TN平均去除率提高26%,缺氧段反硝化能力明显提高,但仍存在最终出水NO3--N平均去除率为负值的问题.进一步将进水C/N从0.8增加到2.5后,MSL系统TN去除率从53.7%上升到89.4%,说明适宜的进水C/N是决定MSL系统氮去除能力的因素之一.分段进水对MSL系统有机物和磷的去除效果无明显影响.

Study of improving nitrogen removal efficiency of two-stage multi-soil-layering filled zeolite in permeable layer

Two stages Multi-soil-layering (MSL) systems filled zeolite in permeable layer was designed for purifying domestic wastewater polluted river water. Because the absence of denitrification negatively influenced the nitrogen removal of MSL system, the step feed method, which added the organic carbon to the second stage without aeration, was applied to MSL systems to improve TN removal efficiency. The results indicated that after the step feed applied to MSL system, the TN removal of MSL system increased by 26% . In addition, appropriate ratio of wastewater is also a equally vital factor to balance the nitrification and denitrification. When the average C/N ratio of wastewater increased from 0.8 to 2.5, the TN removal rate of MSL system increased from 53.7% to 89.4%. Moreover, the step feed had no negative but positive effect to organic matter and phosphorous removal efficiency, and the COD and TP removal rates increase by about 10% after step-feed.