Consolidating Waste Slurry by Vacuum Preloading with Flocculation

Anionic polyacrylamide (APAM) and quicklime are used to improve vacuum preloading of waste slurry in Shanghai, China. To investigate the influence of these reagents on waste slurry sediment consolidation, tests on laboratory-scale models with and without the reagents were conducted and the results analyzed. Sediment settling was recorded and used to calculate the water content changes during vacuum consolidation. After vacuum consolidation, the water content of sediment samples collected at different distances from the drain at the center of the model were measured and pore properties were determined by mercury intrusion porosimetry. The tests with and without reagents indicated that anionic polyacrylamide (APAM) and quicklime can decrease the water content of waste slurry and change the slurry's properties. In addition, the results of the settlement analysis were used to investigate the characteristics of vacuum consolidation.