Polyacrylamide, or PAM, is an organic polymer formed from acrylamide sub-units. Initially, it is produced with a simple, repeating, linear chain structure, but can be modified to form highly structured, branched and cross-linked variants.
It has many uses throughout a wide range of industrial processes, but one of the main purposes is in the separation of solids/liquids in the municipal and industrial waste water sectors.
As part of the manufacturing process, the ionic characteristics of the polymer can be manipulated to achieve varying degrees of anionic (negative charge) or cationic (positive charge) qualities and non-ionic (minimal charge), which is a key factor during the polymer selection process.
The nature of the sludge/effluent to be treated is the driving force behind the initial charge selection (positive or negative) and the individual characteristics of the sludge determine the ionic charge required (high or low cationicity/anionicity). As a basic rule of thumb, municipal waste (primary sludge, SAS and digested sludge) requires a cationic polymer system and industrial effluents (tanneries, aggregate washing and metal finishing) require an anionic treatment.