Evaluation of Oxygen Transfer at Stepped Cascade Aerators

摘要

Dissolved oxygen content in water is one of the most important water quality parameters. In most wastewater treatment plans a lot of oxygen is utilized. Thus it becomes necessary to add oxygen to water in order to comply with the minimum dissolved oxygen concentration in the State’s Water Pollution Control Regulations before the treated water is discharged into rivers or streams. One of the most cost effective post-aeration designs is a stepped-cascade aerator. rnThere are many existing equations for modeling the oxygen transfer at stepped cascade aerators. These equations are mostly empirical and limited to certain situations. Existing models are evaluated against field data taken at four wastewater treatment plants. All models are found to need improvement. The need for a new equation specifically for stepped cascade aerators is evident since existing models were not developed for stepped cascade aerators, but for weirs or other hydraulic structures.