Lin, Li-jen creator Yang, Ping Yi Chairperson Pescod, M.B. Examination Committee Nguyen Cong Thanh Examination Committee Htun, Maung Nay Examination Committee Samorn Muttamara Examination Committee The Government of Republic of China text th Bangkok Asian Institute of Technology 1976 monographic eng

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86 p. Due to the increasing application of pure oxygen activated sludge process in practical usage, the understanding of kinetic and performance of the pure oxygen system is necessary. HSU (1975) conducted the studies of kinetic of microbial growth in the pure oxygen system for batch and once-through system. The main purpose of this research is to investigate the kinetic and performance of a continuous flow pure oxygen process with cell recycle. The model for completely-mixed activated sludge with constant recycle cell concentration was used to investigate the performance of continuous flow oxygenation process. An actual soft drink industrial waste, i.e., Pepsi-Cola combined wastewater, was used as the substrate. Short-term experiments were conducted at various dilution rates for two recycle cell concentration values, i.e., 5000 g/l and 10,000 mg/l. The influent substrate concentration was maintained at 1000 mg/l COD, and the hydraulic recycle ratio, a, at 0.3. A laboratory fermenter was used as aerator. The aerator biological solids and effluent filtrate COD were observed and remained in the steady state. Very high COD removal efficiency was obtained even at very high dilution rate (low detention time), e.g. 92.3% at D(dilution rate) = 2 hr-1 for XR = 10,000 mg/l and 84.9% at D = 1 hr-1 for XR = 5,000 mg/l. No obvious dilute-out point was observed. Neither bulking nor rising sludge occurred during the period of experiment. The SVI values of the mixed liquor was very low within the range of 31.9 to 58.5. The carbohydrate and protein content of the cells has a slightly increasing trend as dilution rate increases, and they are independent of XR. The carbohydrate content was at the average value of 44.8% within the range of 10.1% to 21.6%, and the protein content was at the average value of 45% within the range of 35.6% to 52.2% for dilution rate vary from 1/9 hr-1 to 1/0.5 hr-1 and XR vary from 5000 mg/l to 10,000 mg/l. Cell yield was not related to the dilution rate and sludge loading. The average observed sludge yield was 0.55 (D varied from 1/9 to 1/0.5 hr-1 ', .XR was in the range of 5000 to 10,000 mg/l). Comparing with air activated sludge processes, CMOAS system (pure oxygen system). can provide better performance higher treatment efficiency, better settling characteristics of sludge and no bulking and rising sludge. No significant differences were observed in carbohydrate and protein content of the cells for oxygenation system and air system. The values of æm and ks are related to dilution rates. The higher dilution rate is, the higher values of æm and ks are. Two sets of æm and ks are found for the present CMOAS process, one is æm = 0.4 hr-1 and ks = 92 mg/l for dilution rate higher than 1/3 hr-1 , the other is æm = 0.05 hr-1 and k = 11.1 mg/l for dilution rate below 1/6 hr-1. The maintenance coefficient, kd, appears to have no effect on predicted values of effluent COD, but it influences the biological solids at low dilution rates (below 1/3 hr-1 ). A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand. Thesis (M.Eng.) - Asian Institute of Technology, 1976 Sewage disposal Sewage Purification Activated sludge process Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B23702 http://203.159.5.9/ait-thesis/detail.php?q=B23702 140198 20260817162844.0