Mixing Ability of Aeration Pipe with High Oxygen Transfer Efficiency and Application Example for Wastewater Treatment in the Food Industry

Abstract

　A new aeration pipe has been developed for wastewater treatment in the food industry. Wastewater from the food industry is perishable due to the occurunce of hydrogen sulfide gas or odor from the deposited sludge near the bottom of the aeration tank. In the present work, we employed the high-speed air injection-type aeration pipe to strengthen the stirring effect. The test aeration pipe was installed near the bottom of the water tank, which is 2m in width and 1.75 m in depth of the water. The three-dimensional velocity was evaluated using an electromagnetic velocimeter near the aeration pipe. The three-dimensional circulation flow was observed and the flow rate was evaluated to be about 400 L/min. The good oxygen transfer efficiency (OTE) was obtained from the measurement of the dissolved oxygen. We have shown examples of wastewater treatment conditions in the implemented plant in the food industry.