Study of the Oxygen Supply, Propelling and Mixing Performance Optimization Conditions of an Improved Carrousel Oxidation Ditch

The oxygen supply, propelling and mixing performance optimization conditions of a reactor are studied by adopting a pilot-scale system and a production test system for an improved Carrousel oxidation ditch, including the influence of flow velocity on the mass transfer of DO, the influence of the flow state on the denitrification and energy conservation of the oxidation ditch, and the influence of the particle sizes of floc inactivated sludge on simultaneous nitrification and denitrification (SND). The results indicate that as the flow velocity increases, the mass transfer of DO is better. The appropriate operating condition is regulated and controlled so that the denitrification efficiency of the system can be improved. The starting number of aeration wheels is reduced from 5 to 2, the particle sizes of large-ratio floc in the activated sludge are increased from 20 to 130 μm, and the removal rate of total nitrogen is improved from 44%-49% to 69%-75%.