Applications: Wastewater treatment

In biological nitrogen removal, carbon must be supplied for the denitrification stage. Normally, methanol or other chemicals must be purchased for this purpose. Ultrasound, on the other hand, breaks down excess bacterial biomass (excess sludge), making cellular contents available as a carbon source and feeding them into the denitrification process. At the same time, nitrogen removal increases.

Nitrogen removal

Biological nitrogen removal occurs through nitrification and denitrification.
For the removal process to be successful, it is necessary to ensure an additional supply of carbon to the denitrification stage.
Normally, methanol or another external carbon source is purchased and dosed for this purpose.
Ultrasonic treatment of the excess sludge breaks down the biomass.

This releases cellular components—ideal carbon carriers—which are then available as an internal carbon source in the denitrification stage.
Thus, biological nitrogen removal in the wastewater treatment plant can be maintained or even intensified.
If a portion of the treated sludge is returned to the biological process, the volume of sludge requiring disposal is automatically reduced.
The use of ultrasound in nitrogen removal has proven effective in practice and has been in operation since 2006,

for example, at the Bünde wastewater treatment plant.

Sterilization

Ultrasound is also well-suited for sterilizing suspended and highly concentrated media, such as process and wastewater,

where standard methods like chlorine and UV fail.
Germs attach themselves to suspended particles or flocs and thus easily evade sterilization by UV.
Ultrasound can break up these agglomerates, causing the germs to become isolated and resuspended.
This makes them accessible again to conventional methods, allowing them to be successfully eliminated.
Whether used alone or in combination with conventional methods, effective disinfection is guaranteed.