In order to understand how polymers improve separation of metal hydroxides, it is first necessary to define certain terms to ensure an understanding of their usage for comparative purposes.
A polymer can be either naturally occurring (starches, gums) or synthetic. Its high molecular weight results form the large number of regularly repeating groups of atoms in its structure. It can be either cationic, nonionic or anionic, depending of the charge of its organic functional groups. Anionic flocculants are used in treating plating wastes because they are more active at the higher pH's where heavy metal precipitation occurs. A polymer can function either as a coagulant or flocculant.