Pre-treatments to enhance the biodegradability of waste activated sludge

Pre-treatments to enhance the biodegradability of waste activated sludge: Elucidating the rate limiting step

Gonzales, A. (TU Delft Sanitary Engineering)
Hendriks, A.T.W.M. (TU Delft Sanitary Engineering)
van Lier, J.B. (TU Delft Sanitary Engineering)
de Kreuk, M.K. (TU Delft Sanitary Engineering)

2018

Pre-treatments for waste activated sludge (WAS) are, in most cases, an attempt to increase the biodegradation and/or improve hydrolysis rate of WAS after anaerobic digestion. This review presents an extensive analysis of WAS pre-treatments effectiveness focusing on increasing the biodegradability. In the first part of the review, WAS is considered as a cluster of organic components: proteins, carbohydrates, humic substances and cells. Based on this breakdown into components, the effect of different pre-treatments on each component (and in combination) is described. Also, possible reasons for the contradictory results frequently found among different studies dealing with the same pre-treatment are included. In the second part, the review describes the effects on volatile solids removal by digestion after pre-treatment and on the dewaterability of the final digestate. The energy balance and potential limiting factors for each pre-treatment are also taken into account. From the published works it is concluded that some pre-treatment techniques, such as thermal hydrolysis, thermal phased anaerobic digestion and low-temperature pre-treatment are effective ways to increase energy production and to improve other sludge properties, such as dewatering. However, these techniques are very energy intensive and require a large capital outlay, so research on milder pre-treatment techniques is valuable.

Anaerobic digestion
Methane production
pre-treatment
Review
Sewage sludge
Waste-activated sludge

http://resolver.tudelft.nl/uuid:f99e11ec-5cf0-42ed-92e5-135c3c020fa8

https://doi.org/10.1016/j.biotechadv.2018.06.001

2018-12-07

0734-9750

Biotechnology Advances, 36 (5), 1434-1469

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2018 A. Gonzales, A.T.W.M. Hendriks, J.B. van Lier, M.K. de Kreuk