Abstract: A method is described for the continuous disintegration of microbial sludge in a sewage clarification or sewage treatment plant wherein the microbial sludge is decomposed biologically by bacteria and the resultant sludge (5) is exposed to sonic radiation in a treatment vessel (1) in order to split the cell walls of the microorganisms. With that, the sonic radiation shall be generated asymmetrically in the treatment vessel (1). The intensity of the sonic exposure lies-in an area of 500 to 1500 W/m2 and the sludge (5) is fed with a mean dwell-time of 2 to 4 minutes in counter-flow through the treatment vessel (1). The device for carrying out the method possesses a treatment vessel (1) with an eccentrically arranged sonic resonator arranged within (7).

Abstract: In an apparatus for sieving, grading, sifting, filtering or sorting dry solid substances or solid substances in liquids having a sieve surface provided in a sieve frame and an ultrasound transducer (10) which is associated with the sieve surface (18) and by which oscillations can be fed to the sieve surface, associated with the ultrasound transducer (10) is at least one resonator (14) which bears against the sieve surface (18) and which is tuned to the resonance of the ultrasound transducer and which can be caused to oscillate thereby, in particular with flexural oscillations. The resonator (14) which in an embodiment is disposed in the center of the sieve surface (18) is to be provided with resonance-transmitting elements (16) which project finger-like from the resonator on the sieve surface (18) and which project radially from same in the form of bar resonators.