Anerobic Digestion Sludge

Anaerobic Digestion Sludge Ultrasonic Treatment Anaerobic digestion is the predominant sludge stabilization method used to degrade complex organic substances in the absence of free or dissolved oxygen. The biological processes of anaerobic digestion involve three distinct stages. The solids present in the sewage sludge are brought in contact with a very diverse consortium of microorganisms that first hydrolyzes, then ferments, and lastly gasifies the original long-chain organics and the successive products of each step into stabilized biosolids, methane and carbon dioxide. The rate limiting step in the anaerobic digestion process is hydrolysis, which is the particular area where the effects of the Scogen Ultrasound Reactors are directed. Treatment with the Scogen Ultrasound Reactors enhances the performance of anaerobic digestion due to its floc and cell disintegration action upon the digester feed biomass. This is accomplished using ultrasonically generated cavitation micro bubbles which are increased in size until they implode, causing an acoustic shockwave that impacts the agglomerates of several microorganisms that are present in the waste activated sludge being fed to the digesters. This action breaks the flocs, thus eliminating adequate surfaces for foaming to occur. Individual cells also become accessible for further sonication in which they can serve as nuclei for cavitation bubble formation, which break when the bubbles implode or simply collapse because of exposure to additional acoustic forces and even due to the existing hydraulic shear stress in the sonoreactor.

The described actions upon the treated sludge before anaerobic digestion produce the following benefits:

  • Increased digestion rate
  • Increased VSS destruction
  • Increased gas production
  • Decreased sludge volume for disposal and handling.

An additional benefit that can be obtained is:

  • Improvement of dewatering