ABSTRACT
Sludge solids contain a large fraction of volatile solids or rich in organic content, which makes it easily decomposable, putrescible or unstable. The success in achieving the objectives is related to the effects of the stabilisation operation or process on the volatile or organic fraction of the sludge, to convert them into minerals. The mechanism through which dewater-ability of sludge is improved by sludge digestion, has been studied by Baier and Zwiefelhofer. Main hindrances to the escape of intracellular water are non-uniform particle size distribution and non-optimal operation of sludge-thickeners. Anaerobic digestion is a conventional method used for stabilisation of sludge. In the anaerobic digestion process, the organic content of sludges, is biologically hydrolyzed, liquefied and gasified to methane and carbon dioxide under anaerobic condition. The anaerobic sludge digestion ecosystem is complex, consisting of many different bacteria growing in a close synergistic environment.
