富里酸对深型地下土壤渗滤系统中反硝化过程的影响研究

发布时间：2018-05-02 17:32

本文选题：深型土壤渗滤系统 + 富里酸　；参考：《武汉理工大学》2015年硕士论文

【摘要】：传统的地下土壤渗滤系统对污水中有机物及磷去除效果较好,但是由于反硝化区域缺乏碳源而使脱氮效果不足。传统的外加碳源由于存在各种问题,导致其使用受到限制。有研究发现,难降解的类富里酸在地下土壤渗滤系统1.3m处发生了降解,转化为类蛋白物质,并且在此处,反硝化过程得到了明显的促进。为了探明富里酸在地下土壤渗滤系统的降解规律和其对反硝化过程的作用机制,本次实验采用直径为0.3m,高2.4m的有机玻璃柱模拟深层地下土壤渗滤系统,土壤层高度共2.0m,并从北京阿苏卫卫生填埋场的渗滤液中提取富里酸,对比加入富里酸前后,地下土壤渗滤系统对自配的生活污水中的污染物的去除效果。实验设计水力负荷为8cm/d。在加入富里酸之前,系统出水的总磷、COD、总氮和氨氮的浓度分别为0.068mg/L、51.02mg/L、18.26mg/L和0.68mg/L,去除率分别为98.78%、85.47%、66.38%和97.96%。根据污水中氮沿土壤深度的变化规律发现,在系统表层0~0.2m区域内,主要发生有机物的好氧分解过程,硝化作用被抑制,在0.2~1.1m区域,主要发生硝化反应,而在1.1~2.0m区域,主要发生反硝化脱氮作用,脱氮量为5.42mg/L,占系统总脱氮量的9.98%。结合三维荧光图谱和平行因子分析法对系统中有机物的沿程变化规律进行研究发现,在1.1m之前,类蛋白物质一直减少,而类富里酸一直积累,仅在1.1m处,有很少量的类富里酸转化为可被微生物利用的类蛋白物质,并且在立刻被消耗之后,类蛋白含量一直不变,说明是有机物的缺乏限制了反硝化过程。加入富里酸之后,系统出水总磷、COD、总氮和氨氮的浓度分别为0.051mg/L、58.37mg/L、18.15mg/L和0.49mg/L,去除率分别为99.22%、87.41%、74.86%和98.72%,可以发现,系统的脱氮效率明显提升,脱氮量由36.05mg/L增至54.04mg/L。系统中氮的变化趋势与加入富里酸之前相似,在系统表层0-0.2m区域内,主要发生有机物的好氧分解过程,硝化作用被抑制。在0.2~1.4m区域,主要发生硝化反应,而在1.1~2.0m区域,主要发生反硝化脱氮作用,脱氮量为7.20mg/L,占系统总脱氮量的13.32%,比加入富里酸之前脱氮量提高了1.78mg/L,反硝化脱氮的去除效率提高了32.84%,结合三维荧光图谱和平行因子分析法对系统中有机物的沿程变化规律进行研究发现,在1.4m处,有一部分类富里酸发生降解,转化为可被微生物利用的类蛋白物质,并且马上被利用。系统脱氮效率和脱氮量也因此有所提高,说明,富里酸在一定程度上可以发挥缓释碳源的作用,促进反硝化脱氮过程。
[Abstract]:The traditional underground soil leachate system has better removal effect of organic matter and phosphorus in sewage, but the denitrification effect is insufficient because of the lack of carbon source in denitrification area. The use of conventional external carbon sources is restricted due to various problems. It was found that the refractory fulvic acid-like acid was degraded at 1.3m in underground soil leachate system and converted into protein-like substance, where the denitrification process was obviously promoted. In order to find out the degradation rule of fulvic acid in underground soil leachate system and the mechanism of its action on denitrification process, an organic glass column with diameter of 0.3 m and a height of 2.4 m was used to simulate the deep soil infiltration system in this experiment. The soil layer height was 2. 0 m. Fulvic acid was extracted from leachate of Beijing Asuwei Sanitary Landfill. The effect of underground soil leachate system on the removal of pollutants in domestic sewage was compared before and after the addition of fulvic acid. The designed hydraulic load is 8 cm / d. Before the addition of fulvic acid, the concentrations of total phosphorus (COD), total nitrogen (TN) and ammonia nitrogen (NH3-N) in effluent were 0.068 mg / L, 51.02 mg / L, 18.26 mg / L and 0.68 mg / L, respectively, and the removal rates were 98.78 mg / L, 85.47%, 66.38% and 97.96 mg / L, respectively. According to the variation rule of nitrogen in sewage along the soil depth, the aerobic decomposition process of organic matter was mainly occurred in the 0.2m area of the surface layer of the system, nitrification was inhibited, nitrification occurred mainly in the area of 0.2 ~ 1.1m, but in the area of 1.1 ~ 2.0 m. The denitrification rate was 5.42 mg / L, accounting for 9.98% of the total denitrification. In combination with three dimensional fluorescence spectra and parallel factor analysis, the changes of organic matter in the system were studied. It was found that before 1.1 m, the protein-like substances decreased, while the fulvic acid-like acid accumulated only at 1.1 m. A small amount of fulvic acid was converted into protein-like substances that can be used by microbes, and the content of protein-like substances remained unchanged after being consumed immediately, indicating that the lack of organic compounds limited the denitrification process. After the addition of fulvic acid, the concentration of total phosphorus, total nitrogen and ammonia nitrogen in effluent were 0.051 mg / L, 58.37 mg / L and 0.49 mg / L, respectively, and the removal rates were 99.22g / L, 87.41% and 98.722%, respectively. It was found that the denitrification efficiency of the system was obviously improved, and the denitrification amount was increased from 36.05mg/L to 54.04 mg / L, respectively. The change trend of nitrogen in the system is similar to that before the addition of fulvic acid. In the surface layer of the system, the aerobic decomposition process of organic matter occurs mainly and nitrification is inhibited in the 0-0.2 m region of the surface layer of the system. Nitrification occurred mainly in the region of 0.2 ~ 1.4m, while denitrification occurred mainly in the region of 1.1 ~ 2.0m. The amount of nitrogen removal was 7.20 mg / L, which accounted for 13.32% of the total denitrification of the system, which was 1.78 mg / L higher than that before the addition of fulvic acid, and the removal efficiency of denitrification increased 32.84%. The study found that, At 1.4 m, some fulvic acids were degraded and converted into protein-like substances that can be used by microbes. The nitrogen removal efficiency and denitrification amount of the system were also improved, which indicated that fulvic acid could play the role of slow release carbon source to a certain extent and promote denitrification and denitrification process.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

【参考文献】