Knowledge of the oxygen mass transfer of aerators under operational conditions in a full-scale wastewater treatment plant （WWTP） is meaningful for the optimization of WWTP, however, scarce to best of our knowledge. ...Knowledge of the oxygen mass transfer of aerators under operational conditions in a full-scale wastewater treatment plant （WWTP） is meaningful for the optimization of WWTP, however, scarce to best of our knowledge. Through analyzing a plug flow aeration tank in the Lucun WWTP, in Wuxi, China, the oxygenation capacity of fine-bubble aerators under process conditions have been measured in- situ using the off-gas method and the non-steady-state method. The off-gas method demonstrated that the aerators in different corridors in the aeration tank of WWTP had significantly different oxygen transfer performance; furthermore, the aerators in the same corridor shared almost equal oxygen transfer performance over the course of a day. Results measured by the two methods showed that the oxygen transfer performance of fine-bubble aerators in the aeration tank decreased dramatically compared with that in the clean water. The loss of oxygen transfer coefficient was over 50% under low-aeration conditions （aeration amount 〈 0.67 Nm 3 /hr）. However, as the aeration amount reached 0.96 Nm 3 /hr, the discrepancy of oxygen transfer between the process condition and clean water was negligible. The analysis also indicated that the non-steady-state and off-gas methods resulted in comparable estimates of oxygen transfer parameters for the aerators under process conditions.展开更多
基金supported by the Major Water Project of the National Science and Technology (No.2011ZX07319-001-004, 2011ZX07301-002)
文摘Knowledge of the oxygen mass transfer of aerators under operational conditions in a full-scale wastewater treatment plant （WWTP） is meaningful for the optimization of WWTP, however, scarce to best of our knowledge. Through analyzing a plug flow aeration tank in the Lucun WWTP, in Wuxi, China, the oxygenation capacity of fine-bubble aerators under process conditions have been measured in- situ using the off-gas method and the non-steady-state method. The off-gas method demonstrated that the aerators in different corridors in the aeration tank of WWTP had significantly different oxygen transfer performance; furthermore, the aerators in the same corridor shared almost equal oxygen transfer performance over the course of a day. Results measured by the two methods showed that the oxygen transfer performance of fine-bubble aerators in the aeration tank decreased dramatically compared with that in the clean water. The loss of oxygen transfer coefficient was over 50% under low-aeration conditions （aeration amount 〈 0.67 Nm 3 /hr）. However, as the aeration amount reached 0.96 Nm 3 /hr, the discrepancy of oxygen transfer between the process condition and clean water was negligible. The analysis also indicated that the non-steady-state and off-gas methods resulted in comparable estimates of oxygen transfer parameters for the aerators under process conditions.
