polyelectrolytes, chemical contaminants, health effects, analytical techniques
Chemical contaminants that occur in drinking water are not usually associated with acute health effects when compared to microbial contaminants and are usually given a lower priority. Those that are of concern have cumulative toxic properties such as metals and substances that are carcinogenic. Some of these potentially hazardous chemical contaminants are a consequence of the treatment chemicals themselves e.g. organic polyelectrolytes used as coagulant aids in water treatment. The presence of residues of the un-reacted monomer in these polyelectrolyte products is a cause for concern. Historically, inorganic coagulants such as aluminium sulphate and ferric chloride have been used as coagulants/flocculants in the treatment of drinking water. The residual amounts of these chemicals were easy to detect and to control using readily available standard methods. The increasing use of polyelectrolytes has created a problem for the potable water industry as there are no readily available methods for the determination of residual polyelectrolyte concentration. This study aims at extending existing analytical techniques and comparing them to determine results that are most accurate and reliable to the quantification of residual polyelectrolytes.