Coagulation kinetics: A laboratory experiment

Abstract

The purpose of the experiment described is to acquaint the students with the problems of colloid stability. For more advanced students, the experiment can be extended to verify the Schulze-Hardy rule.

Kinetics and coagulation performance of snail shell biomass in pharmaceutical Effluent.

“…In this case, the particles (monomers, doublets and triplets) are seen decreasing linearly with time until it gets to a point, where the coagulation rate attains the maximum value, which does not change any more with further increasing electrolyte (SSC) concentration, minimum value is recorded (7.25S) corresponding to the half -period of rapid coagulation. This assertion is in agreement with previous work [24]. Also in " fig".7, there are forces of repulsion and attraction between the approaching particles.…”

“…These are electrostatic repulsion between the monomers and the sum of the particle which leads to van der waals attraction of its dispersion component. The repulsion is an exponential, whereas the attraction is a hyperbolic function of the distance [24]. Above all, attraction appears to be more dominant as seen in "fig".7.…”

A model of flocculation by very-high-molecular-weight polymers

“…In [5], flocculation in the system PAA-sol AgJ at various KNO3 concentration was studied. Here, some of these data are interpreted in terms of the model.…”

“…3 that the sol contained a considerable fraction of very small particles. In [5] flocculation was measured in terms of the flocculation degree F~xp defined as:…”

“…If these values diner, the arithmetic mean was chosen to represent the flocculation degree. A more detailed descripiton of the methods and materials is given in [5].…”