併同生物膜與活性污泥程序之硝化及脫硝攝磷特性研究; The Nitrification and Denitrifying Phosphate Uptake Characteristics of A Combined Biofilm-Activated Sludge Process

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Title:	併同生物膜與活性污泥程序之硝化及脫硝攝磷特性研究;The Nitrification and Denitrifying Phosphate Uptake Characteristics of A Combined Biofilm-Activated Sludge Process
Authors:	游勝傑;Sheng-Jie You
Contributors:	環境工程研究所
Keywords:	脫硝除磷菌;硝化菌;生物營養鹽去除系統;分子生物技術;16S rDNA;Denitrifying Phosphate Accumulating Organism
Date:	2001-06-26
Issue Date:	2009-09-21 12:13:39 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	生物營養鹽處理程序中存在著硝化菌與磷蓄積菌的SRT衝突問題，以及脫硝菌與磷蓄積菌的碳源競爭問題，本實驗室發展的併同生物膜與活性污泥程序(TNCU-I)可有效解決上述兩大問題。本研究針對TNCU-I程序，了解其脫硝除磷反應特性，並利用A2O模廠為對照組及分子生物技術，探討TNCU-I程序之硝化現象、硝化菌的種類及數量，以及嘗試找出程序中是否有脫硝除磷菌(Denitrifying Phosphate Accumulating Organisms, DNPAO)之存在，並進行TNCU-I程序反應槽體積最佳化設計。研究結果顯示TNCU-I程序無論是硝化穩定性、比硝化率、總氮去除率等各方面皆較A2O高，而TNCU-I模廠中RBC生物膜的確可補充好氧槽活性污泥在低SRT下所降低的硝化效果。此外TNCU-I活性污泥及RBC以及A2O活性污泥等三個樣品中皆可測到以Nistrosospira屬為主的亞硝酸菌以及以Nitrospira屬為主的硝酸菌，且各硝化菌的比例皆以TNCU-I活性污泥高於其他兩樣品。脫硝攝磷實驗結果發現TNCU-I反應槽中DNPAO對整體磷的攝取量大於47%，對整體脫硝貢獻度為42%。故DNPAO的存在對脫硝、攝磷均有相當大的貢獻。而批次實驗亦顯示攝磷速率隨內部PHA增加而加速，且污泥外部有殘留COD存在會對釋磷有利，而對攝磷不利，表示污泥若能在厭氧狀態下攝取越多的COD、釋出越多的正磷酸鹽、累積越多的PHA時，將使DNPAO或者non-DNPAO (不屬於DNPAO之單純磷蓄積菌)於其後續的缺氧/好氧狀態下越傾向於攝磷作用。另由實驗了解DNPAO需要大於2小時的水力停留時間才得以累積足夠的PHA量而不至於被non-DNPAO淘汰。因此設計TNCU-I反應槽之最佳化操作應為在SRT為10天且總水力停留時間為10小時下，厭氧、缺氧、好氧體積比為3：5：2，並於好氧槽上加裝1~2段RBC，使其上生物膜質量約略等於500mg/l之好氧槽MLSS，控制硝化液迴流比為3.5倍進流水流量，迴流污泥為0.5倍進流水流量，並使好氧槽DO為2.0mg/l。在TNCU-I活性污泥菌相中，除了有大量的硝化菌存在外，尚有大量極有可能為DNPAO之細菌。而RBC生物膜上之硝化菌存在的種類較為多樣，且亦有大量脫硝菌之存在，證實RBC生物膜的確可同時提供硝化及脫硝之功能，其絲狀菌亦多，這與RBC生物膜之膠羽結構較為緊密亦有關係。且無論是活性污泥或是RBC生物膜，其菌相均以Proteobacteria為主，其中又以β-subclass為最多，亦可發現γ-subclass及ε-subclass。CFB group亦同時存在於兩個污泥樣品中，但在活性污泥樣本方面以Cytophagales group為主，而RBC生物膜以Flavobacteria group為主。活性污泥樣品中未能測到gram positive細菌的存在，而RBC生物膜上可測到gram positive low G+C細菌。 The TNCU-I process, which added a RBC in the aerobic tank of A2O process, can solve the SRT confliction of nitrifier and phosphate accumulating organisms (PAOs), and the carbon competition of denitrifier and PAOs. In this thesis, the nitrification performance, nitrifier species and abundance were compared with an A2O process by molecular biotechnology. On the other hand, the denitrification/phosphate-uptake or denitrification/phosphate-release characteristics, the existence of DNPAO (Denitrifying Phosphate Accumulating Organisms) of the TNCU-I process was also investigated. Additionally, the optimization of the anaerobic-anoxic-aerobic tank of the TNCU-I process was also performed. The results showed that the nitrification stability, specific nitrification rate and total nitrogen removal efficiency of TNCU-I process were all higher than A2O process. It was also proven that the RBC biofilm in the TNCU-I process could compensate for the overall nitrification performance when the TNCU-I process is operated at a low SRT. Additionally, the genera Nitrosospira and Nitrospira were identified as the predominant ammonia-oxidizer and nitrite-oxidizer among TNCU-I activated sludge, TNCU-I RBC biofilm and A2O activated sludge. It was also showed that the nitrifier abundance of TNCU-I activated sludge was higher than TNCU-I RBC biofilm and A2O activated sludge. The denitrification/phosphate-uptake experiments showed that the DNPAO contributed 47% of overall phosphate uptake and 42% of denitrification performance. Thus, the existence of DNPAO was advantageous for de-nitrogen and de-phosphate. The batch result also showed that the phosphate uptake rate increased with the increase of intracellular PHA of the sludge. Besides, the present of residue COD in the bulk solution enhance the phosphate uptake, but decrease the phosphate release performance. This implied that the DNPAO and non-DNPAO tend to take up more phosphate when it take up more COD, release more phosphate and accumulate more PHA in the anaerobic condition. Additionally, the DNPAO need more than 2 hrs anaerobic hydraulic retention time for competition the carbon with non-DNPAO. According to the reaction kinetics of the batch and pilot plant experiments, the optimum operation conditions of TNCU-I process are: SRT=10 days, HRT=10 hrs, the volume ratio of anaerobic:anoxic:aerobic is 3:5:2, 1-2 RBC were added in the aerobic tank, the recycled nitrification liquid and recycled sludge are 3.5 and 0.5 times of influent flow, and the DO is 2.0 mg/l. In the TNCU-I activated sludge, both nitrifier and DNPAO-like bacteria was identified. The nitrifier species in the RBC biofilm was more diverse, and a certain denitrifier was identified. This revealed that the RBC biofilm could contribute to nitrification and denitrification performance. Additionally, a lot of filamentous bacteria was also identified might be due to the dense biofilm structure. In both samples, the Proteobacteria was the predominant bacteria. The β-subclass, γ-subclass and ε-subclass were the common bacteria that was observed in both samples. The Cytophagales group and Flavobacteria group were also present in activated sludge and RBC biofilm, respectively. No gram positive bacteria was observed in activated sludge but in RBC biofilm.
Appears in Collections:	[Graduate Institute of Environmental Engineering ] Electronic Thesis & Dissertation

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