| 摘要 |
<p>A method and a device for reducing the volume of excess sludge capable of providing a high solubilization capacity and reducing a total cost and the size of equipment; the method, comprising the steps of adding solubilizer to the excess sludge produced by applying a biological treatment to organic waste water, acting ultrasonic wave on the waste water, applying a reduced pressure expansion treatment to the waste water, and applying the biological treatment again to the waste water to reduce the volume of the excess sludge; the device, comprising a means for adding the solubilizer to the excess sludge produced by applying the biological treatment to the organic waste water, an ultrasonic wave application means for acting ultrasonic wave to the waste water, and a reduced pressure expansion means installed on the downstream side of the ultrasonic wave application means and applying the reduced pressure expansion treatment to the excess sludge.</p> |
