Abstract
The disposal of waste activated sludge (WAS) is difficult for many
wastewater treatment plants. It contains large quantities of water which is
difficult to be removed. In this study ultrasonically assisted dewatering of
WAS from pulp and paper mill has been studied. Ultrasound could improve the
laboratory scale dewatering of WAS. Wet mass of fresh sludge could be
decreased tens of percentages and dry solids content (DS) increased 2 %-units
when using a short ultrasonic pre-treatment. Ultrasound seemed to disintegrate
especially large and fragile protozoa cells, which contained a lot of bound
water. Released water could be removed and DS increased both at batch
centrifugation and at continuous belt filter pressing. The benefit from
released water for dewatering was lost with too violent ultrasonic treatment
because some of the dewatering properties of sludge worsened during ultrasonic
treatment. There is a good potential to improve dewatering of WAS with
ultrasound but both technically and economically it is better to fractionate
the part of the sludge for ultrasonic treatment which will easily be
disintegrated and has positive effect on dewatering.
| Original language | English |
|---|---|
| Title of host publication | Proceedings |
| Subtitle of host publication | 19th International Congress on Acoustics, ICA 2007 |
| Publisher | Sociedad Española de Acústica |
| Pages | 6410-6414 |
| Volume | 10 |
| ISBN (Print) | 978-1-61567-707-8 |
| Publication status | Published - 2007 |
| MoE publication type | A4 Article in a conference publication |
| Event | 19th International Congress on Acoustics, ICA 2007 - Madrid, Spain Duration: 2 Sept 2007 → 7 Sept 2007 |
Conference
| Conference | 19th International Congress on Acoustics, ICA 2007 |
|---|---|
| Abbreviated title | ICA 2007 |
| Country/Territory | Spain |
| City | Madrid |
| Period | 2/09/07 → 7/09/07 |
