Ultrasound disintegration for biogas plants and WWTPs
Disintegration means the breakdown of biogenic sludge into minute particles by external forces. The resulting increase in surface area causes an acceleration of the organic breakdown process, and thereby results in an increased biogas yield. In addition, the release of exo-enzymes from the external cell layer increases the enzyme activity in the digester.
In ultrasonic disintegration, the 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, they 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. From the implosion, which releases high pressures and temperatures, strong impact and shear forces occur in the area immediately around the cavities, and these cause the surrounding micro-organisms to disintegrate.