Dissolved oxygen “stuck” for ten hours
Are you adding an anti-foaming agent to the SBR? Soya oil?
No. The wastewater is very oily though. it is a dairy wastewater.
Ah! The surface tension due to oil is an interesting theory! The grease trap does not work for us since the infpuent is basically an emulsion because the cleaning chemicals are designed to emulsify oils it just flows straight through the grease traps.
High BOD loading is also a good reason.
The aeration system is working OK. But yes the air could be increased to help the situation.
Thanks for your answers!