DISTRIBUTION OF WATER IN SLUDGES IN RELATION TO THEIR MECHANICAL DEWATERING

The water content of a sludge is generally considered to be constituted by two fractions: free water and bound water. This classification does not, however, characterize the binding energy of water to the solid phase. By using the dilatometric technique, the bound water content of sludge was measured as a function of the mechanical dewatering strain applied to the sludge. Thus, it was possible to separate water into different categories (free water, bound water removable by moderate mechanical strain, bound water removable by maximal mechanical strain, bound water not removable mechanically), depending on its behavior during mechanical dewatering.