- 學位論文
平板式固定生物程序處理廢水碳氮之研究
Simultaneous Removal of Wastewater Carbon and Nitrogen Compounds Using Plate Entrapped Mixed Microbial Cell Process
摘要
固定生物細胞程序(Entrapped Mixed Microbial Cell, EMMC)為生物脫氮技術方法之一，其相較傳統活性污泥法此處理技術具有占地面積小、操作簡易、不須迴流污泥及污泥產率低，可大幅減少廢污水廠污泥處置成本等優點。若能應用此技術於廢污水處理工程，將能打破傳統生物脫氮分槽程序，以提升傳統生物脫氮程序處理效率。 本研究主要應用EMMC製成形狀均勻之平板污泥，以實驗室合成污水模擬試驗探討不同操作因子，包括如填充率、溶氧控制、碳氮比(COD/N)、水力停留時間(HRT)及不同進流氨氮濃度(NL)等，探討在不同操作條件下對硝化、脫硝及總氮去除率之影響，並期能找出實驗設計下最佳操作條件，提升目前生物脫氮處理效能。 研究結果顯示，以進流COD為150 mg/L及氨氮濃度為25 mg/L進行試驗，曝氣模式及碳氮比皆影響總氮去除率，其中又以曝氣模式之影響平板式EMMC較大，實驗結果以曝氣模式1：1及碳氮比COD/N = 12有最佳操作條件，此條件下各效能COD去除率、硝化效率及總氮去除率分別可達96%、93%及84%；此外進行改變不同水力停留時間，以HRT = 18 hr時有最佳處理效率，而隨著HRT減少，COD去除率、硝化效率及總氮去除率下降。另一方面，以不同進流氨氮濃度25 mg/L、50 mg/L及200 mg/L作試驗，其最佳操作條件碳氮比COD/N分別為12、9及6，COD去除率分別可達96%、96%及94%，硝化效率分別可達93%、79%及47%，總氮去除率分別可達84%、76%及39%。 整體而言，平板式固定生物處理程序異於傳統生物脫氮分槽程序，能於單槽反應槽下同時進行碳、氮之去除。
並列摘要
Entrapped mixed microbial cell (EMMC) process has been developed for wastewater treatment with the intention to achieve high simultaneous removal of carbon and nitrogen in a single through-put process. EMMC offers many advantages over the conventional activated sludge process (CASP) because it requires significantly smaller footprint, simple maintenance and operation, no sludge recycling, longer sludge retention time (SRT), low production of biomass and reducing the operating and set-up cost. It is believed that the EMMC technology could drastically enhance the nitrogen removal efficiency over CASP when nitrogen contaminant is of the major threat. In this study, EMMC was prepared into flat sheet of plates. Synthetic wastewater was prepared daily to investigate the operating conditions for optimal organic and nitrogen removal. Key operating parameters include biomass packing ratio, dissolved oxygen (DO), carbon to nitrogen ratio (C/N) and hydraulic retention time (HRT), which affect the nitrification and denitrification efficiency in the EMMC reactor. The results demonstrated that when influent COD and NH4+-N were at 150 mg/L and 25 mg/L, respectively, aeration pattern and carbon to nitrogen ratio would considerably influence the total nitrogen removal efficiency. The COD, nitrification and total nitrogen removal efficiency were achieved up to 96%, 93% and 84% during aeration mode of 1 h on and 1 h off with HRT of 18 h and C/N ratio of 12. In addition, lower HRT operating condition appeared to achieve better COD removal and nitrification efficiency. On the other hand, different ammonia concentrations (25 mg/L, 50 mg/L and 200 mg/L) with C/N ratio (12, 9 and 6) in the influent would result in COD removal efficiency 96%, 96% and 94%, nitrification 84%, 76% and 39%, total nitrogen removal 84%, 76% and 39%, respectively. In conclusion, with appropriate operating condition, EMMC process exhibited advantages over the CASP with improved organic and nitrogen removal efficiency simultaneously.