The polyacrylamide flocculation has the principle

To investigate the mechanism of polyacrylamide flocculation,dissolved craft and dosing technology choices. PAM is the most widely used synthetic flocculant. A long molecular chain , it is an amide group (--- CONH2) affinity with many substances,adsorption to form hydrogen bonds , which make bridging between particles can be adsorbed,so that several or even dozens of particles connected together to produce floc , accelerated particles sinking sun , making it ideal flocculant. In the experiment there was added a solution of partially hydrolyzed polyacrylamide alumina hydrate into the polymeric anionic cations adsorbed on the alumina , the viscosity rapidly increased or brother of the gel . This same general mechanism of flocculation of a molecule that is similar to the adsorption of several particles simultaneously , so that they pull together , rapidly settling,sedimentation rate depends on the concentration of the coagulant and suspended solids concentrations .
After application of water treatment experts for many years , generally considered polyacrylamide flocculation catechesis(anionic polyacrylamide) are: (1) Because of its polarity genes - amide group, easy to hydrogen bond by its role in the sediment particles adsorbed surface ; (2) Because it has a long molecular chain , a large number of long-chain in the water level has great absorption surface area, the flocculation effect can take advantage of the long-chain bridging between the particles , the particles form large flocs,accelerated sedimentation.(3)By means of polyacrylamide flocculating - coagulation , coagulation process in water treatment sludge may occur in double ionization compressed into pellets reduce the stability of the molecule under gravity particles combine simplicity dispersed anionic polymers may be substituted with an anionic group ; (4) The water and a natural polymer material and the suspended solids in water , or between its hydrolysis before dosing chemical coagulants ionic interactions , may be complexation reactions ;

(5) Since the molecular chain is fixed on the surface of different particles , forming bridges between the respective polymerized solid particles . PAM is a relatively chemically active polymers. Because the molecular side chain amide group activity, so that the polymer obtained many valuable properties. Nonionic PAM flocculant Because without ionic functional groups , as compared with the anionic flocculant PAM class has the following characteristics : flocculation little affected by salt water PH value and volatility ; under medium or alkaline conditions , its flocculation ( sedimentation rate ) as good as anionic, but under acidic conditions , but better than anionic, strong floc strength than anionic polymer flocculant . PAM molecular weight anionic flocculants are usually lower than that of anionic or non-ionic polymer , which is primarily to clarify the performance by charge neutralization is obtained . The main function of this type of flocculant flocculation negatively charged colloids , with turbidity, discoloration and other functions for the high water content of organic colloids .

 

Pre:How to ensure the SLES 70% application safe    Next:How to ensure the SLES 70% application safe