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Interparticle bridging

The interparticle bridging mechanism was affected by the charge [7], adsorption sites [5] of particles extending in the flocculation system, the physical characteris-... [Pg.128]

In a second hypothesis, one can consider that the adsorption is mainly due to hydrogen bonds and that electrostatic attraction between polymer and particles only brings them together. In such case, the influence of c and r on the stability should be related to the number of amide groups available for hydrogen bounds and the increase of salinity should lead to the collapse of the chain and reduce the probability of interparticles bridging. [Pg.141]

It has been discovered that starch adsorbs onto graphite, a phenomenon that is employed in processing sulfide ores containing graphite.460 The adsorption of starch on quartz and hematite has been studied in more detail.461 In this case, adsorption is related to the balance between electrostatic interactions and hydrogen bonding. Interparticle bridging is also observed as a result of the adsorption of starch molecules at the interface (flocculation). [Pg.313]

Interparticle bridging will not be as effective, since the force to loop the bridge around will not be as strong without the force of the rapid mix. Colloid particles will not effectively be utilized as seeds for nucleation sites because, without rapid mix, the coagulant may simply stay in one place. Finally, the compression of the double layer will not be as effective if unaided by the force due to the rapid mix. The force of the rapid mix helps push two colloids toward each other, thus enhancing coagulation. Flence, because of all these stated reasons, coagulation should take place in a rapidly mixed tank. [Pg.565]

Polyacrylamide (30% hydrolysed) is an anionic polymer which can induce flocculation in kaolinite at very low concentrations. Restabilisation occurs by overdosing, probably by the mechanism outlined in Fig. 7.32. Dosages of polymer which are sufficiently large to saturate the colloidal surfaces produce a stable colloidal system, since no sites are available for the formation of interparticle bridges. Under certain conditions, physical agitation of the system can lead to breaking of polymer-suspension bonds and to a change in the state of the system. [Pg.259]

Depasse, J., Coagulation of colloidal sflica by alkaline cations Surface dehydration or interparticle bridging , J. Colloid Intetf. Sci., 194. 260. 1997. [Pg.1054]

Flocculation of alumina suspensions obtained by the sequential addition of polystyrene sulfonate (M j, = 4600) and cationic polyacrylamide (M, = 4,000,000) at pH 4.5 is compared in Figure 7.33 with that obtained using single polymers. While the anionic polystyrene sulfonate had only a minor effect, cationic polyacrylamide did not produce any flocculation. However, when used together, both polymers adsorb completely. This coadsorption is attributed to the interaction of complexes between cationic polyacrylamide and the polystyrene sulfonate at the solid-liquid interface. The mechanism of the superior flocculation obtained with the dual polymer system is illustrated schematically in Figure 7.34. The anionic polystyrene sulfonate adsorbs on alumina surface and acts as an anionic anchor for the adsorption of the long-chain cationic polymer, which ultimately provides interparticle bridging and excellent flocculation. [Pg.430]

In former investigations by using a combined titration technique [25] we could already show that the turbidimetric endpoint of the polyanion-polycation complex formation in the absence of kaolin correlates quite well with the one in the presence of kaolin. This agreement means that polyanion-polycation interactions are dominant in this system and the complexes with kaolin were formed due to an interparticle bridging through the polyelectrolyte complexes formed on kaolin. [Pg.581]

Addition of surface active organics that provide interparticle bridging... [Pg.241]


See other pages where Interparticle bridging is mentioned: [Pg.276]    [Pg.307]    [Pg.405]    [Pg.128]    [Pg.211]    [Pg.365]    [Pg.8]    [Pg.113]    [Pg.170]    [Pg.250]    [Pg.405]    [Pg.913]    [Pg.593]    [Pg.615]    [Pg.276]    [Pg.70]    [Pg.42]    [Pg.259]    [Pg.55]    [Pg.429]    [Pg.430]    [Pg.430]    [Pg.501]    [Pg.42]    [Pg.260]    [Pg.66]    [Pg.2765]    [Pg.237]    [Pg.227]    [Pg.36]    [Pg.169]    [Pg.207]    [Pg.227]    [Pg.228]    [Pg.138]    [Pg.206]   
See also in sourсe #XX -- [ Pg.405 ]

See also in sourсe #XX -- [ Pg.405 ]

See also in sourсe #XX -- [ Pg.241 ]




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