Technological and Economic Importance of Sludge Dewatering

A sufficient degree of dewatering of sludge is essential for sludge extruding and drying in belt dryers. The higher the dry residue of dewatered sludge, the lower will be the energy demand for drying and the investment for a belt dryer. Influence of different factors on sludge dewatering are discussed in detail. Also the right choice of polymer together with laboratory tests and methods for evaluation of overdosing of flocculants are presented. The chapter closes with the measurement of maximum achievable dry residue in dewatering of sludge and the calculation of the minimum cost for polymer application.