Polyelectrolytes: Potential Chloroform Precursors

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Science  10 Jun 1977:
Vol. 196, Issue 4295, pp. 1205-1206
DOI: 10.1126/science.196.4295.1205


Chloroform residues in potable water are generally thought to be derived only from the organic matter in the raw water upon chlorination. However, formation of chloroform at concentrations of a few micrograms per liter from widely used polyelectrolyte coagulants and coagulant aids has now been observed. Most of the ten commercial polyelectrolyte formulations tested reacted with chlorine to form chloroform under thermal conditions. This reaction was found to be strongly activated by ultraviolet irradiation. Since the chemical composition of polyelectrolytes and their impurities are little known, further studies are required before a full assessment of their benefits and potential harm can be made.