The effect of high dissolved oxygen in an aeration tank
By: Tom Frankel
Post Date: May 23rd 2019
When it comes to aeration, there is a such thing as too much air. This is also known as dissolved oxygen in aeration, or D.O. There is also the problem of not enough DO. Therefore, DO must be maintained within a reasonable range. Implementing a control in the amount of DO present in the water improves the efficiency of wastewater treatment. In addition, it greatly reduces energy consumption.
When an operator over aerates activated sludge, not only is it extremely wasteful, but it can also cause serious operational problems. Aeration and dissolved oxygen in aeration keeps microorganisms in suspension during the treatment cycle. As the microorganisms lose their food, they collide and stick together forming what is called a floc. When a tank has too much DO, this is characterized by a breaking up of flocs. This poses a major problem when the mixed liquor reaches the secondary treatment stage. The process of settling may become an issue if the floc is broken into smaller and less dense areas and may even re-suspend.
How can SSI Help?
SSI can assist in providing maximum efficiency. We calculate optimal diffuser density based on a standard dissolved oxygen requirement. In addition, the general recommendation for activated sludge is a fine bubble diffuser. This efficiently increases dissolved oxygen in aeration to optimal levels for microorganisms to thrive. This creates that perfect mixed liquor with a nice floc.
There are several membrane materials available with an SSI fine bubble diffuser. This includes our patented PTFE membrane and EPDM. This comes equipped on both our tube and disc diffusers in addition to our economy single-mold line. PTFE membranes provide a longer-lifespan in less than optimal wastewater conditions. This includes wastewater that is high in volatile organic compounds, chemicals, and even temperature.
Contact SSI to see what we can do to help solve your DO needs.
Mr. Frankel co-founded SSI in 1995 with experience in design and distribution of engineered systems. He is in charge of sales, marketing and operations in the company. Mr. Frankel holds multiple US patents related to diffusers. He is a graduate of Washington University in St. Louis.