- 期刊
本土性含氨氮無氧氧化微生物之混合族群在廢水除氮上的應用
Application of Anaerobic Ammonia Oxidizing Bacteria from Local Sediment on Wastewater Treatment
摘要
氨氮無氧氧化反應是氮循環中較不明顯的分支，於1977年首次由Broda預測自然界應存在進行氨氮無氧氧化的細菌。其特色是能於無氧環境中將氨氮與亞硝酸根直接反應生成氮氣，不需硝化菌群與脫硝菌群的參與，這個反應對於氧氣濃度還很低的古大氣，具㈲維持氮循環平衡的重要功能。本研究利用完全閉氣之馴養槽，從環境污泥中馴養出本土性含氨氮無氧氧化微生物混合菌群，經基因定序鑑定其中有一菌與'Candidatus Brocadia anammoxidans'有97%相似度，在混菌狀態下能去除入工基質(BM)與廢水基質(WM)中的無機氮成分。小型血清瓶測試中，氨氮無氧氧化菌群單位重量污泥之除氮活性達0.94 kg N/kg dw/day。微生物固定式反應器的開發有助於微生物應用於廢水處理，且固定化具㈲保存菌量、使微生物富集化、減少水體環境衝擊的效果。固定式反應器在批次流與連續流操作中，BM基質皆達到85%以上除氮效率；而以廢水基質WM測試，除氮處理效果在79.2%~85.5%之間。菌相方面，微生物固定化後，在DGGE (denaturing gradient gel electrophoresis)圖譜中菌相趨於單純、有明顯的優勢菌種出現。 綜合言之，由本土污泥培養出之氨氮無氧氧化菌群在實驗室的小型血清瓶及固定 式反應器中具有良好的除氮效率。由於微生物具有產氮氣特性，膠羽容易上浮流失，利用擔體將微生物固定化能解決此一困擾，對於實場化應用十分有利。
並列摘要
The anaerobic ammonia oxidation (Anammox) reaction is a minor pathway in the nitrogen cycle. It was first proposed in 1977 by the scientist Broda, who predicted the existence of anaerobic ammonia oxidation microorganisms. He also predicted that these bacteria could uptake ammonia and nitrite in an anaerobic environment, and produce nitrogen gas without the participation of nitrifiers and denitrifiers. The Anammox reaction was significant for the balance of the nitrogen cycle at the beginning years of the Earth, when oxygen concentration was low in the atmosphere. In this study, a gas-impermeable reactor was applied to cultivate anaerobic ammonia oxidation bacteria from environmental sediment. It successfully cultivated a mixed culture of microorganisms contained a strain of Anammox cells which had a genetic similarity to 'Candidatus Brocadia anammoxidans' of 97%. The Anammox cell cultivated in this study was in the form of mixed culture, which could eliminate inorganic nitrogen in either a basic medium (BM) or wastewater medium (WM). The nitrogen elimination ability of the Anammox mixed culture is 0.94 kg N/kg dw/day, via a serum bottle test. A microorganism-immobilized reactor was developed to enhance the efficiency of wastewater treatment since it preserved more biomass, enriched microorganism growth and buffered the impact of unsuitable water. Under batch-flow and continuous-flow operation, the reactor reached more than 85% efficiency in BM, and 79.2%~85.5% efficiency in WM. As for the microbial community, the DGGE (denaturing gradient gel electrophoresis) plot exhibits a trend of cell simplification and the appearance of major species. In conclusion, the Anammox cell cultivated from local sediment has an excellent ability to treat nitrogen-containing wastewater in serum bottles and a bench-scale reactor. Owing to nitrogen production, the Anammox cells tend to become buoyant in water, it is promising to apply 'Candidatus Brocadia anammoxidans' by immobilizing them.