| 4种不同工况生物滤池净化效能与微生物特性分析 |
| 摘要点击 1875 全文点击 579 投稿时间：2018-04-24 修订日期：2018-05-30 |
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| 中文关键词 生物滤池 净化效能 微生物群落结构 高通量测序 自养硝化 异养反硝化 |
| 英文关键词 biofilter purification efficiency microbial community structure high-throughput sequencing autotrophic nitrification heterotrophic denitrification |
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| 中文摘要 |
| 为了从微生物层面探讨曝气、挂膜周期、池形（或流态）改变对生物滤池净化效率的影响，试验设计了4种不同工况的生物滤池，即MAVF、NAVF、NVF、BHF，其中前三者为垂直流滤池，最后一种为折流式水平流滤池.4组滤池框架和滤料相同，MAVF与BHF串联，且于试验前期运行1 a，NAVF及NVF为新启用滤池.4组滤池采取同步序批式运行，其中MAVF、NAVF进行间歇曝气，其余两组未曝气.于新启用滤池挂膜阶段，对4组滤池同步处理生活污水的净化效率进行持续监测，并于挂膜结束后采集基质样品分析滤池微生物群落结构特征.结果表明，3组垂直流滤池的净化效率显著高于水平流滤池；曝气显著提高了滤池的净化效能，但与滤池微生物成熟度相比，前者的影响更弱.4组滤池内均无明显的硝氮、亚硝氮积累，反硝化进行得很彻底.16S rDNA高通量测序分析表明，4组滤池的多样性指数高低是BHF > MAVF > NAVF > NVF，表明滤池愈成熟，多样性指数愈高.4组滤池内微生物以兼性异养菌为主，且以异养反硝化脱氮菌最为丰富.NVF及BHF滤池内发生了异养硝化过程，曝气促进了滤池内好氧硝化菌的富集.4组滤池内均未检测到好氧聚磷菌，磷的去除以反硝化聚磷为主.试验工况下，滤池对总氮的去除率不高主要归结于滤池内尚未富集到自养硝化菌或其丰度不高，后者导致滤池的氨氧化能力有限，进而影响总氮去除.以上研究结果表明，不同工况的调整会影响到生物滤池的氧化还原状态和功能菌富集，进而最终影响净化效率. |
| 英文摘要 |
| To explore the effects of aeration, microbial acclimation period, and pool shape or flow pattern change on the purification efficiency of biofilters at the microbiological level, four biofilters with different working conditions, that is, MAVF, NAVF, NVF, and BHF, were studied. The first three are vertical-flow biofilters and the last one is a baffled-flow biofilter. The four filters filled with the same ceramsite were made of organic glass. The MAVF filter was connected with the BHF filter in series and was operated for one year prior to the trial. The NAVF and NVF filters are newly activated filters. The four filters that were used to treat domestic sewage were synchronously operated in batch mode in this study. The MAVF and NAVF filters were intermittently aerated in contrast to the other two. During the period of microbial acclimation of the newly activated filters, the purification efficiency of the four filters was continuously monitored and the microbial community structure characteristics were analyzed at the end of microbial acclimation. The results show that the purification efficiency of the three vertical-flow filters is significantly higher than that of the horizontal-flow one and aeration significantly enhances the purification efficiency. However, aeration has a weaker effect on the efficiency than the microbial maturity of the filter. An apparent accumulation of nitrates or nitrites in the four filters was not observed, indicating that the denitrification was rather thorough. The 16S rDNA high-throughput sequencing analysis shows that the diversity index of the four filters is BHF > MAVF > NAVF > NVF, indicating that the more mature the filter is, the higher is the diversity index. Most of the packing microorganisms are facultative heterotrophic bacteria and the most abundant are heterotrophic denitrifying bacteria. Heterotrophic nitrification occurs in the NVF and BHF filters and aeration promotes the enrichment of aerobic ammonium-oxidizing bacteria. Aerobic phosphorus-accumulating organisms were not detected in the four filters. Therefore, phosphorus was mainly removed via denitrifying phosphorus accumulation. Under the test conditions, the removal rate of total nitrogen was not high, mainly because nitrifying bacteria were not enriched in the filter or their abundance was insufficient. The latter resulted in the limited ammonium-oxidizing ability of the filter, thus affecting the removal of total nitrogen. The above-mentioned results show that the adjustment of different working conditions will affect the redox status and associated enrichment of functional bacteria inside the biofilter, which will ultimately affect the purification efficiency. |
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