Ultrasonic Disintegration of Sewage Sludge to Increase Biogas Generation

I. Zawieja and L. Wolny

Abstract
The value of methane fermentation in sewage sludge treatment is well established. It causes volume reduction, improves stability, destroys pathogens, and increases the amount of biogas obtained, which can be used as an energy source. Ultrasound treatment destroys cell membrane continuity, increasing the bioavailability of the soluble fraction of organic matter, which contributes to the intensification of hydrolysis. This paper presents the investigations concerning the influence of ultrasonic pretreatment of sewage sludge on the effectiveness of 25-day stabilization process. In the first series untreated sludge was used, and for the second and third series the following treatment parameters were applied: ultrasonic field amplitude 39.25 μm and sonification time 5 or 10 minutes. During the investigation unitary biogas production of 9.8 L g–1 VSS and 6.29 L g–1 VSS was obtained, for sonication time 10 and 5 minutes, respectively. Biogas generation from unconditioned and stabilized sludge was 4.43 L g–1 VSS.

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords
Excess sludge, ultrasonic field (UF), disintegration, anaerobic stabilization, biogas