Characterization Of Flocs Research Articles

Floc stabilization for multiple microscopic techniques

A nondestructive stabilization technique for the characterization of microbial flocs which permits the application of correlative microscopic techniques is described. Flocs embedded in agarose are retained in a porous, resilient medium which allows for the transport, staining, washing, and subsampling of the flocculated material directly within a plankton chamber with minimal or no destructive forces. A single agarose disc can be subdivided into numerous sections for analysis by several microscope types and associated techniques.

Particle-size characterization of flocs and sedimentation volume in electrolyte clay suspensions

The variation of the particle-size of flocs in clay suspension with the salt concentration and the correlation of the particle-size with the sediment behaviour of the suspensions have been studied. The particle-size distribution of flocs was determined by means of the sedimentation balance. Due to the increase of the salt concentration in the suspensions, the particle-size of flocs showed marked increases for the salt concentration range of 0 to 0.01 M, followed by smaller increases for the salt concentrations higher than 0.01 M. A negative correlation was observed between the mean particle-diameter of flocs in the suspensions and the zeta potential. The sediment volume of the clay suspensions of pH 7 was found to be positively correlated with the mean particle-diameter of flocs. The void ratio of the sediment exhibited a rapid decrease with increasing depth at the surface zone and a subsequent slow decrease at greater depths.

Characterization of flocs in coarse suspensions in a non-polar medium

The flocculation of coarse suspensions of NaCl in liquid paraffin was studied. Floc characteristics such as size, porosity and number of primary particles were investigated for suspensions of NaCl in liquid paraffin by application of the Koglin concept. The dispersed NaCl had a narrow size distribution. Variables under investigation were particle size (mean volume diameter 6.5, 8.1 and 16.2 μm) and solid concentration (0–2% m/m). The results showed that the floc size and floc porosity increased with NaCl concentration up to 2% (m/m). No relationship was found between floc porosity and sediment porosity. For suspensions with small particles and a solid concentration above 3%, a structuring of flocs with high porosity hindered the settling of the flocs.