| 摘要 |
<p>A continual process breaks down activated sludge by micro-organic activity and discharges the residual sludge into a treatment container in which it is exposed to ultrasonic energy, breaking down micro-organic cell walls. The ultrasonic emissions are asymmetric and in the energy range 500-1500 W/m. The sludge has a median residence time of 2-4 minutes and passes in contra-flow through the container. The ultrasonic source (7) is located on one side of the reactor vessel. During the process, secondary sludge is continually fed to and removed from the container. The ultrasonic emissions are in the frequency range 16 to 70 kHz, pref. 20-25 kHz. The circulating sludge is exposed to ultrasonic treatment pref. 10 times. The sludge may be thickened prior to ultrasonic treatment. Also claimed is a commensurate assembly of volume pref. 40 litres receiving pref. 0.25 litres of sludge per second.</p> |
