| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 100 === 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.
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