带有淹没区的生物滞留池优化设计与运行研究

发布时间：2018-11-25 17:49

【摘要】：生物滞留池是最具代表的低影响开发和面源控制技术之一,淹没区的设置直接影响了生物滞留池的脱氮效果,而含氮污染物的削减已经成为地表水环境达标的控制性指标之一,开展生物滞留池淹没区的设计及运行研究对该技术的推广应用和含氮污染物削减工程的实施具有重要的现实意义。本文试验研究了生物滞留池的填料高度、水力停留时间、干湿交替运行、降雨强度及淹没区和碳源等因素对污染物去除的影响,比选出优化脱氮的技术参数,并通过高通量测序分析生物滞留池内微生物种群结构,解释了高效脱氮机理,主要工作及结论如下：1、以TN去除为目标,同时兼顾了TP、NH4+-和TSS的去除率,试验分析了生物滞留池的填料高度和水力停留时间的影响,结果表明：相对较优的运行参数是填料高度为800mm,水力停留时间为5h,此时对TN、TP、NH4+-N、TSS的去除率分别为42%、85%、85%、93%。2、试验分析了生物滞留池淹没区高度和有无碳源对脱氮效果的影响,结果表明：随着淹没区高度的增加,对NH+4+-N的去除率降低,对NO3--N和TN的去除率增加；当淹没区高度为450mm,并且添加废报纸作为碳源时,对NH4+-N、N03-N、TN的去除率分别达到73%、68%、50%。3、试验研究了生物滞留池经历不同干旱长度(1周、2周、3周、7周)后对N类污染物去除效果的影响：有淹没区的生物滞留池对TN的去除率更高并且湿润后脱氮性能迅速恢复,干旱三周时,TN去除率可达29%至35%,且脱氮性能在进水后快速恢复：当控制一周至三周的干旱长度时,不仅能保证有淹没区但无碳源的生物滞留池在恢复湿润时对TN的去除效果,而且TN去除率在进水之后可由39%升高至56%。4、试验模拟了大、中、小不同降雨强度对生物滞留池污染物的去除效果。结果表明：与无淹没区的生物滞留池相比较,有淹没区的生物滞留池对TP和NH4+-N的去除率较高,但对TSS的去除率较低；在任何降雨强度下,有淹没区和碳源的生物滞留池对TN和NO3--N的去除率均是较高。5、对生物滞留池的上层(-50mm～300mm)和下层(-400--650mm)填料的微生物群落结构进行高通量测序分析：上层填料的优势菌种主要为异养好氧菌,能够氧化分解有机物,下层填料的优势菌种主要是TM7类群,根据N的沿程变化分析可知NO3--N的去除主要发生在下层填料中。本文试验研究结果可以指导生物滞留池的设计及运行,特别是淹没区的设计。
[Abstract]:Biological retention pool is one of the most representative low-impact development and non-point source control techniques. The setting of submerged area has a direct impact on the nitrogen removal effect of biological detention pool, and the reduction of nitrogen-containing pollutants has become one of the control indexes of surface water environment. The research on the design and operation of the submerged area of biological detention ponds is of great practical significance for the popularization and application of the technology and the implementation of the nitrogen pollutant reduction project. In this paper, the effects of packing height, hydraulic retention time, dry and wet alternate operation, rainfall intensity, inundated area and carbon source on pollutant removal were studied. The high throughput sequencing was used to analyze the microbial population structure and explain the mechanism of high efficiency denitrification. The main work and conclusions were as follows: 1. The removal rate of TN and TP,NH4-and TSS were taken into account at the same time. The effects of packing height and hydraulic retention time on the filling height and hydraulic retention time of the biological detention tank were analyzed. The results showed that the relatively optimal operating parameters were the packing height of 800mm and the hydraulic retention time of 5 h, and the optimum operation parameters were as follows: the packing height was 800mm and the hydraulic retention time was 5 h. The removal rates of TSS were 42 / 8510 / 93.2. the effects of the height of the inundated area and the presence of carbon sources on the denitrification effect were analyzed. The results showed that the height of the inundated area increased with the increase of the height of the inundated area. The removal rate of NH 4-N decreased, and the removal efficiency of NO3--N and TN increased. When the height of inundated area was 450 mm, and waste newspaper was added as carbon source, the removal rate of TN from N03-NN reached 73% and 68th and 50.3. the biological detention tank experienced different drought lengths (1 week, 2 weeks). After 3 weeks and 7 weeks of drought, the removal rate of TN was higher and the removal rate of TN could reach 29% to 35% after 3 weeks of drought. And the denitrification performance recovered quickly after the influent: when the drought length of one to three weeks was controlled, the removal effect of TN could be ensured not only in the submerged area but without carbon source, but also in the biological retention tank without carbon source. The removal rate of TN can be increased from 39% to 56. 4 after influent. The experiment simulates the effect of large, medium and small rainfall intensity on the removal of pollutants in the biological detention tank. The results showed that the removal rate of TP and NH4-N in the submerged area was higher than that in the submerged area, but the removal rate of TSS was lower. Under any rainfall intensity, the removal rates of TN and NO3--N in the submerged area and the biological retention pool with carbon source were higher than those in the control group. The microbial community structure of the upper (- 50mm~300mm) and the lower (- 400--650mm) fillers in the biological retention tank was analyzed by high throughput sequencing. The dominant bacteria in the upper packing were heterotrophic aerobic bacteria, which could oxidize and decompose organic matter. According to the analysis of the variation of N along the path, the removal of NO3--N occurred mainly in the lower packing. The experimental results can guide the design and operation of biological detention tank, especially the design of submerged area.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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