THE EFFECT OF CHLORIDE AND OZONE ON ORGANIC COMPOUNDS IN WATER - A LITERATURE REVIEW
Report No DWI0733

Jun 1987

SUMMARY

The presence of chemical by-products of drinking water disinfection in water supplies is a topic of interest to government departments, water authorities and companies and environmental pressure groups. The prediction of products of the reaction of disinfectants with organic compounds, particularly those originating from pollution incidents, is of considerable interest. This report reviews the recent literature on the effects of two of the most common disinfectants, chlorine and ozone, on organic compounds under aqueous conditions.

From the studies reviewed it is evident that both chlorine and ozone can react with a wide range of organic compounds, the extent and rate of reaction and the nature of the products formed being dependent on a number of parameters, such as pH, concentration of disinfectant and organic substrate, contact time, inorganic content and the nature of the organic substrate. The majority of the studies published during the period reviewed deal with reactions of chlorine and ozone with either humic substances or aromatic compounds. Humic substances react with both ozone and chlorine to produce a series of carboxylic mono-, di-, tri- and poly-acids. In addition, chlorine gives a series of chlorinated carboxylic acids, chloroaldehydes, chloroketones, chloroalkanes and chlorinated heterocyclic compounds.

Aromatic hydrocarbons give rise to chlorinated and oxygenated products on reaction with chlorine, but with ozone they are oxidised to produce C2 and C4 diacids. There are fewer studies on the reactions of chlorine or ozone with compounds such as amines, amino acids, aromatic heterocyclic compounds, pesticides and surfactants.

Copies of this report may be available as an Acrobat pdf download under the 'Pre 2000 Reports' heading on the DWI website.