For the design of aeration systems in municipal wastewater treatment plants, DWA-A 131 is the key guideline for process design of activated sludge systems, while DWA-M 229-1 governs the planning, sizing, arrangement, and energy evaluation of aeration and mixing systems.
In addition, DIN EN 12255-6 defines fundamental requirements for activated sludge processes, whereas DIN EN 12255-15 standardizes clean-water oxygen transfer testing.
Practically relevant parameters include oxygen demand, SOTR or αSOTR, alpha factor, airflow rate, submergence depth, pressure loss, control range, and adequate mixing without sedimentation. These parameters must be evaluated for minimum, average, and maximum operating conditions. For oxygen transfer measurement and verification, DWA-M 209 and internationally ASCE/EWRI 2-22 are commonly used. Universal fixed guideline values exist only to a limited extent because design always depends on treatment objectives, basin geometry, wastewater characteristics, and energy-efficiency requirements.
Sources:
