PHYSICAL, CHEMICAL AND MECHANICAL PROPERTIES OF DREDGED SLUDGE AND EFFECT OF DESICCATION ON THE PROPERTIES

Abstract

  This paper examines the relationship between physical, chemical and mechanical properties and effect of the desiccation of dredged sludge. The characteristics of dredged sludge with high water content can be improved by various methods, i.e., solidification with stabilizing materials, mechanical dehydration, desiccation and stabilization by heat. The physical and chemical properties were investigated using consistency tests, ignition loss (Li) tests, pH tests, XRF analyses and X-ray diffraction analyses. The mechanical properties were measured by standard consolidation and permeability tests. The experimental results indicate that 1) desiccation can dramatically reduce the liquid limit of sludge and 2) the reduction rate of the compression indices between the original wet materials and the desiccated materials is proportional to the ignition loss of the materials when Li exceeds 12%.