Sedimentation settling rate acceleration

Flocculation is accelerated and higher overflow rates are achieved by external or internal recirculation of settled soflds into the feed which leads to the collection of fine particles by interception. Addition of conditioned fine sand to the feed induces separation by differential sedimentation, and sometimes increases overflow rates to 6—8 m/h. 

The molecules of both HSl and HS2 have a high colloid stability due to their very low collision efficiency and small size which prevent them from settling under normal gravitational acceleration. Their separation in a centrifuge with a g value of some thousands is still practically inefficient. This fact is used for sedimentation analysis to investigate the destabilization and aggregation rate of the coagulation process of humic substances. 

Sedimentation The settling of suspended particles or droplets due to gravity or an applied centrifugal field. The sedimentation rate (or velocity) divided by acceleration is termed the sedimentation coefficient. The sedimentation coefficient extrapolated to zero concentration of sedimenting species is termed the limiting sedimentation coefficient. The sedimentation coefficient reduced to standard temperature and solvent is termed the reduced sedimentation coefficient. If the sedimentation coefficient is... 

The methodology is a variation on the particle-fractionation techniques routinely used in soil mineralogy studies. Sedimentation and centrifugation allow the routine sepraration of particles of < 2 pm (Laird Dowdy, 1994 Soukup et al., 2008). Particle fractionation is based on the differential settling of the particles in a liquid so that centrifugation increases the rate of sedimentation, accelerating the process. The relation between the sedimentation rate and particle size is given in Stoke s Law (Stokes, 1851) ... 

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