Study Of Operational Condition Of Jet-loop Compact Reactor And The Treatment Of High Level Organic Wastewater

With rapid development of modern industry, the amounts as well as types of pollutants is becoming more and more, thus the conventional activated sludge process could not satisfied the elevating requirements of wastewater treatments. In this study, development and application of high rate aerobic reactor which has the most extensive recognition in the wastewater control field was investigated.Based on the domestic and international studies, a kind of aerobic jet-loop compact reactor (JLCR) was designed, and was taken it into operation for almost two years. JLCR covered all characteristics of jetting aeration, fluidized bio-bed and deep hole aeration etc., therefore it could fundamentally solve the problem of substrate-transfer and then could gain higher mass-transmission efficiency, larger volumetric loading rate (VLR), stronger opposition of sudden loading rate, steady effects, and etc.During the treatment of pharmaceutical wastewater with JLCR, a good COD removal efficiency over 75% with the influent COD concentration of 8000 mg/L could be observed. When the influent COD concentration was varying from 4000 to 10000 mg/L, the effluent concentration was always kept below 2000 mg/L. At the same time, the reactor could withstand a wide range of temperature and pH changes, and showed a steady performance. At the influent COD concentration of 4000 mg/L, the reactor could reached a VLR of 22 g[COD]/(L·d), which is ten times larger than traditional aerobic methods and is suitable for the pretreatment of high strength and well biodegradable wastewater. However, the reactor couldn't effectively reduce NH4+-N because of excess substrate and higher VLR. Besides, the activated sludge got a higher activity, lower production rate and larger MLSS level of 8 kg/L, and the OUR test also showed a higher value than that of the general activated sludge.The operating conditions such as aeration rate and recirculation flow rate, were studied and the optimal value under current operation circumstances were 9m3/h and 4m3/h, respectively, with the corresponding VLR of 11 kg [COD]/(L·d). In addition, the recirculation situation also affected the dissolving ability of oxygen.Above all, JLCR can reach a better performance than conventional activated sludge process and will show better oxygen-filling ability given the addition of throat-shape pipe. The size of jet muzzle had an important effect on the oxygen-filling ability of the whole reactor, and oxygen was filled more effectively with the decreasing of the muzzle size.