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It is well recognised that processes such as anaerobic digestion can be enhanced. A range of mechanical, thermal, chemical and biological pre-treatment technologies have been developed for this purpose. Mechanical treatment of biological sludges using ultrasound has been successful. This is based on the principle of using sound energy at frequencies above 20 kHz. The extreme conditions of the collapsing cavitation bubbles induces cell lysis of the sludge material. This increases the availability of the organic substrate for improved downsteam digestion.

The sonix™ technology has been evaluated around the globe and demonstration trials have been undertaken resulting in a number of full-scale installations. This paper presents results from sonix™ plants treating thickened waste activated sludge (TWAS) prior to anaerobic digestion. The work has proven that the use of ultrasound can effectively enhance anaerobic digestion. TWAS is inherently difficult to digest. However, the application of sonix™ makes it behave as if it were a primary sludge.

The benefits of the technology include; increased biogas production, better solids destruction, improved dewatering characteristics of the digested sludge mixture, and relatively short payback periods subject to site conditions and operations.

Document Type: Research Article


Publication date: January 1, 2005

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  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

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