Factors Affecting Oxygen Delivery Concentration in Downflow Zone of Loop Bioreactor
The downflow zone oxygen transfer capacity of the loop bioreactor is mainly affected by factors such as the diameter of the guide tube,the height of the overflow weir of the guide tube,and the aeration volume,which have im-portant effects on the denitrification and phosphorus removal treatment effect of the reactor wastewater.To investi-gate the influence of the above factors on the oxygen transfer capacity of the downflow zone,a combination of numer-ical simulation and experiments was used to study the oxygen transfer capacity of the downflow zone of the circulat-ing reactor.A custom program coupled with Higbie mass transfer theory was used to simulate oxygen mass transfer.The dissolved oxygen concentration and overflow volume simulated under different aeration intensities were com-pared with the measured values,and the results showed an error within 8％,indicating that the numerical simulation model and method were correct and feasible.Subsequently,the effects of aeration volume,guide tube diameter,and guide tube overflow weir height on the oxygen transfer capacity of the downflow zone were explored.The results showed that when the aeration volume increased from 20 L/min to 50 L/min,the oxygen volumetric mass transfer coefficient increased from 2.04 h-1 to 4.45 h-1;when the guide tube diameter decreased from 325 mm to 250 mm,the oxygen volumetric mass transfer coefficient increased from 3.99 h-1 to 4.42 h-1;when the guide tube overflow weir height increased from 10 mm to 25 mm,the oxygen volumetric mass transfer coefficient decreased from 4.17 h-1 to 4.00 h-1;in-creasing the aeration volume and reducing the guide tube diameter can significantly enhance the oxygen transfer capacity of the downflow zone.The oxygen transfer capacity of the downflow zone can be controlled by adjusting the aeration volume,guide tube diameter,and guide tube overflow weir height to construct an anoxic zone.Response surface analysis showed that when the guide tube diameter is 250 mm and the guide tube overflow weir height is 10 mm,the oxygen transfer capacity of the reactor downflow zone is optimal.
万方数据
维普
