不同固相有机碳源反硝化性能的研究

发布时间：2019-05-20 17:06

【摘要】：地下水资源被人类广泛应用。我国有大量的水资源,但人口众多,人均用水量低于世界平均水平的四分之一,且地下水中硝酸盐的污染严重,因此在我国水资源缺乏与恶化是一个严重的环境问题。微生物法处理硝酸盐污水的优点为高效率及低能耗。本实验的目的是通过批实验和柱实验对比研究不同固相有机碳源对反硝化的促进作用,筛选出合适的固相碳源,为地下水硝酸盐的修复提供理论依据。实验采用秸秆、麦麸、米糠、可生物降解塑料作为反硝化固相碳源,研究不同碳源的反硝化效果。实验分为两个阶段:第一阶段为批试验,主要研究固相碳源本身的释放规律及反硝化过程中硝酸盐氮、亚硝酸盐氮、氨氮的变化情况,最终筛选出适合的固相碳源;第二阶段为柱实验,以麦麸、米糠、可生物降解塑料为固相碳源,对比三种固相碳源对硝酸盐氮的去除效果以及在处理过程中亚硝酸盐氮和氨氮的积累情况。实验结果表明,在批试验中可生物降解塑料反硝化效果显著,硝酸盐氮的去除率达到99.5%,且氨氮和亚硝酸盐氮的积累较少;其次是米糠,硝酸盐氮的去除率为78.3%,而麦麸和秸秆作为碳源时,去除率仅为29.9%和18.8%。另外实验还发现,当进水硝酸盐浓度在一定范围内升高时,硝酸盐氮的去除率会相应升高。柱吸附实验发现,可生物降解塑料对硝酸盐几乎没有吸附作用,而麦麸和米糠对进水硝酸盐均有明显的吸附效果。在反硝化柱实验的反应初期,麦麸、米糠为碳源时,由于其对硝酸盐的吸附作用,导致硝酸盐氮的去除效果较为显著,最大去除率分别为97.7%、99.7%。当可生物降解塑料作为碳源时,硝酸盐氮的去除效果跟批试验有显著不同,去除率仅为33.3%,且亚硝酸盐氮积累量比麦麸和米糠高,峰值可达8.5 mg/L,而氨氮的积累量始终较小,维持在0.91 mg/L左右。此外,以麦麸和米糠为碳源时,硝酸盐氮的去除率分别为66.4%和67.2%,亚硝酸盐的积累量分别为0.15 mg/L和0.14 mg/L,氨氮的积累量分别为5.16 mg/L和6.17 mg/L。柱实验结果表明,米糠是最为适宜的固相碳源。
[Abstract]:Groundwater resources are widely used by human beings. There are a large number of water resources in China, but the population is large, the per capita water consumption is less than 1/4 of the world average level, and the nitrate pollution in groundwater is serious, so the lack and deterioration of water resources in China is a serious environmental problem. The advantages of microbial treatment of nitrate wastewater are high efficiency and low energy consumption. The purpose of this experiment is to study the promoting effect of different solid organic carbon sources on denitrification by batch experiment and column experiment, and to select the suitable solid carbon source, which provides a theoretical basis for nitrate remediation in groundwater. Straw, wheat bran, rice husk and biodegradable plastics were used as denitrifying solid phase carbon source to study the denitrification effect of different carbon sources. The experiment is divided into two stages: the first stage is batch test, which mainly studies the release law of solid carbon source itself and the changes of nitrate nitrogen, nitrite nitrogen and ammonia nitrogen in denitrification process, and finally selects the suitable solid carbon source. The second stage was column experiment, in which wheat bran, rice husk and biodegradable plastics were used as solid carbon sources to compare the removal efficiency of nitrate nitrogen and the accumulation of nitrate nitrogen and ammonia nitrogen during treatment. The experimental results show that the denitrification effect of biodegradable plastics is remarkable in batch test, the removal rate of nitrate nitrogen is 99.5%, and the accumulation of ammonia nitrogen and nitrite nitrogen is less. The removal rate of nitrate nitrogen was 78.3%, while that of wheat bran and straw as carbon source was only 29.9% and 18.8%. In addition, it is found that when the influent nitrate concentration increases in a certain range, the removal rate of nitrate nitrogen will increase accordingly. The column adsorption experiment showed that the biodegradable plastics had little adsorption effect on nitrate, while wheat bran and rice husk had obvious adsorption effect on influent nitrate. At the initial stage of denitrification column experiment, when wheat gluten and rice husk were used as carbon sources, the removal effect of nitrate nitrogen was remarkable because of their adsorption of nitrate, and the maximum removal rates were 97.7% and 99.7%, respectively. the maximum removal rates of nitrate nitrogen were 97.7% and 99.7%, respectively. When biodegradable plastics were used as carbon source, the removal efficiency of nitrate nitrogen was significantly different from that of batch test, the removal rate was only 33. 3%, and the accumulation of nitrate nitrogen was higher than that of wheat bran and rice husk, and the peak value was 8. 5 mg/L,. However, the accumulation of ammonia nitrogen was always small, maintained at about 0.91 mg/L. In addition, the removal rates of nitrate nitrogen and nitrite were 66.4% and 67.2% and 0.14 mg/L and 0.14 mg/L, respectively, and the accumulation of nitrate was 0.15 mg/L, and 0.14 mg/L, respectively, when wheat bran and rice husk were used as carbon sources, the removal rates of nitrate nitrogen were 66.4% and 67.2%, respectively. The accumulation of ammonia nitrogen is 5.16 mg/L and 6.17 mg/L., respectively. The results of column experiment show that rice husk is the most suitable solid carbon source.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X523

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