MUCT工艺处理生活污水短程脱氮的实现及硝化菌群动态变化

发布时间：2018-11-26 13:44

【摘要】：采用连续流MUCT工艺处理实际生活污水,研究短程生物脱氮的实现,并采用实时荧光定量PCR方法(quantitative real time PCR,QPCR)分析全程脱氮向短程脱氮转变过程中氨氧化细菌(ammonia-oxidizing bacteria,AOB)和亚硝酸盐氧化菌(nitrite-oxidizing bacteria,NOB)的动态变化。通过降低溶解氧浓度为0.5 mg·L~(-1)和缩短水力停留时间为6 h,实现短程硝化,亚硝酸盐积累率达到90%。在短程硝化稳定运行阶段总氮去除率高达90%以上,远远大于全程阶段的74%。QPCR结果表明全程脱氮阶段水力停留时间的缩短使AOB细胞数呈现下降的趋势,NOB细胞总数稳定维持在108 cells·(g dried sludge)~(-1)。短程脱氮阶段,AOB细胞数小幅度上升,由3.17×106 cells·(g dried sludge)~(-1)增长到1.32×107 cells·(g dried sludge)~(-1),同时AOB占全菌的比例也小幅度增长。NOB的细胞数在5.9×107~1.78×108 cells·(g dried sludge)~(-1)之间波动。NOB占全菌的比例由1.44%下降到0.47%。因此,MUCT工艺处理实际生活污水的系统中NOB丰度降低及活性抑制是实现并维持短程生物脱氮的重要原因。短程脱氮运行期间由于控制低溶解氧浓度和短的水力停留时间,AOB丰度及相对含量没有显著增加,甚至下降,但不会影响氨氮和总氮的去除。
[Abstract]:The realization of short-range biological denitrification was studied by continuous flow MUCT process, and real-time fluorescence quantitative PCR (quantitative real time PCR,QPCR) was used to analyze the ammonia-oxidizing bacteria (ammonia-oxidizing bacteria,) during the process of denitrification to short-range denitrification. AOB and nitrite oxidizing bacteria (nitrite-oxidizing bacteria,NOB). By reducing the dissolved oxygen concentration to 0.5 mg L ~ (-1) and shortening the HRT to 6 h, short-cut nitrification was achieved, and the nitrite accumulation rate reached 90%. The removal rate of total nitrogen was more than 90% in the stable operation stage of short-cut nitrification. The result of 74%.QPCR, which was much larger than that in the whole stage, showed that the number of AOB cells decreased due to the shortening of HRT in the whole process of denitrification. The total number of NOB cells remained stable at 108 cells (g dried sludge) ~ (-1). The number of AOB cells increased slightly from 3.17 脳 10 ~ 6 cells (g dried sludge) ~ (-1) to 1.32 脳 10 ~ 7 cells (g dried sludge) ~ (-1) during short-course denitrification. The number of NOB cells fluctuated between 5.9 脳 10 ~ 7 ~ (-1) and 1.78 脳 10 ~ (8) cells (g dried sludge) ~ (-1). The percentage of NOB in the whole bacteria decreased from 1.44% to 0.47%. Therefore, the decrease of NOB abundance and the inhibition of NOB activity are the important reasons for the realization and maintenance of short-range biological denitrification in the system of MUCT process for the treatment of domestic sewage. Under the control of low dissolved oxygen concentration and short HRT, AOB abundance and relative content did not increase or even decrease during short-range denitrification operation, but the removal of ammonia nitrogen and total nitrogen was not affected.
【作者单位】：北京工业大学环境与能源工程学院;
【基金】：国家自然科学基金项目(51278007,51578016) 国家高技术研究发展计划项目(2012AA063406)~~
【分类号】：X799.3

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