AWWA B453:2006 pdf download.Polyacrylamide
PAM is usually produced by polymerizing acrylamide monomer (AM) alone to form a nonionic polymer, with acrylic acid or acrylic acid salts to form an anionic polymer, or with a cationic monomer to form a cationic polymer. Anionic PAM may also be produced by alkaline hydrolysis of nonionic PAM. Certain properties of the polymer, such as molecular weight, can be varied by controlling the polymerization reaction. The charge density of the polymer is varied by adjusting the relative amount of acrylic acid or cationic monomer added prior to polymerization. .
Powdered PAM is usually manufactured by first polymerizing the monomer(s) in aqueous solution to form a gel and then grinding and drying the gel. Emulsion PAM is usually manufacured by first emulsifying droplets of monomer(s) and water in a hydrocarbon oil before polymerization is initiated. The liquid polymerized emulsion is sold as manufactured or further modified to remove water or oil. Solution PAM can be manufactured by aqueous polymerization of the monomer(s) or by dissolving emulsion- or powder-form PAM in water.
Because PAM includes a broad family of polymers, each of which may be manufactured in three different product forms, qualifications for the physical and chemical requirements described in Sec. 4.4 and Sec. 4.5 cannot be generically established. More importantly, none of the physical or chemical requirements in this standard can be used to identify the PAM product with the best performance in a specific application. Only actual performance testing can determine this. Therefore, these requirements are best used to ensure product quality and uniformity after a specific PAM product has been chosen for use.
The total solids of a PAM product may be the same as or greater than the active polymer content. Total solids and active polymer content may be different because of the possible presence of inert or inactive ingredients. The supplier should be willing to reveal the active polymer content of a specific product. The difference between the measured total solids and the supplier's stated active polymer content is the nonvolatile inert or inactive content of the PAM product.AWWA B453 pdf download.