BioPush is an ultrasound reactor used to disintegrate biogenic sludge in biogas and waste water treatment plants (WWTPs). The process increases the surface area of the sludge particles resulting in accelerated organic breakdown, reduced processing costs and higher biogas yields.
BioPush is innovative because the ultrasound is fixed on the outside of the reactor. This means that no disrupting/interfering body is left in the medium to be treated. In traditional ultrasonic reactors, there is usually direct contact between the sonotrode and the substrate, and this inevitably results in continual gradual wear of the sonotrodes.
The BioPush reactor body is rectangular and hosts 6 ultrasound transducers on each side. The 24 ultrasound elements cause the entire body to “swing” with a frequency of around 22 kHz, which virtually quadruples the amplitude.
The effect of the sludge is at least as high as with the standard rod transducer technology but the entire reactor is 100 % maintenance free and has a durability of three years and more. Even problematic substrates such as highly thickened mixed sludges from waste water treatment plants or from agricultural fermentation plants are treated at maximum performance.
Benefits of BioPush ultrasound sludge disintegration
- Ultrasonic breakdown increases the surface area of sludge particles - this accelerates the organic breakdown process
- Exo-enzymes released from the external cell layer increase enzyme activity in the digester
- Substrate viscosity is reduced
- Energy consumption is reduced
- Residue that needs to be disposed of is reduced
- Biogas yield is increased
How ultrasonic sludge disintegration works
In ultrasonic disintegration, electrical oscillations created by a generator are transformed by a converter (sonic transducer) into mechanical vibrations. These vibrations are transferred into the surrounding medium by means of a device known as a sonotrode.
Following the rhythm of the ultrasonic frequency, the vibrations cause high alternating positive and negative pressure phases, depending on whether the oscillator is expanding or contracting at the time.
During the negative pressure phase, microscopical cavities are formed in the liquid exposed to the ultrasonics; these then collapse in the subsequent positive pressure phase. This process is known as cavitation.
The implosion releases high pressures and temperatures. Strong impact and shear forces occur in the area immediately around the cavities causing surrounding micro-organisms to disintegrate.