内循环强化曝气生物滤池脱氮性能的研究

Study on Enhanced Nitrogen Removal by Internal Recirculation in BAF Reactor

为了提高单级升流式陶粒曝气生物滤池(UBAF)的脱氮效果,对其进行了局部改造并增加了出水内循环。处理灰水的中试结果表明,出水内循环可以明显强化脱氮效果。最佳内循环比为100%,此时对TN的去除率可达82%,与没有内循环时(54%)相比则去除率提高了28%。填料层沿程的DO呈山谷形分布,谷底位于填料层70 cm处,其既是反硝化的拐点,又是反硝化与硝化的分界点。

To improve nitrogen removal efficiency of the up-flow BAF （UBAF） using ceramsite as carrier, it was reconstructed locally and an internal recirculation system of effluent was set up. The pilotscale test results for treatment of grey water demonstrate that the internal recirculation of effluent can effectively enhance nitrogen removal. When the optimal recirculation ratio is 100% , the TN removal rate is increased from 54% without internal circulation to 82% , with rise of 28%. The valley-type DO profile varies along the carrier bed height, and the DO valley bottom is at 70 cm which is a point of inflection for denitrification and a boundary between nitrification and denitrification.