The formation of disinfection by-products in water treated with chlorine dioxide

In this study, chlorine dioxide (ClO2) was used as an alternative disinfect ion agent with humic acid as the organic precursor in a natural aquatic env ironment. The major topics in this investigation consisted of the disinfect ion efficiency of ClO2 the formation of disinfection by-products (DBPs), an d the operating conditions. The results indicated that the pH value (pH 5-9 ) did not affect the efficiency of disinfection while the concentration of organic precursors did. The primary DBPs formed were trihalomethanes (THMs) and haloacetic acids (HAAs). The distribution of the individual species wa s a function of the bromide content. The higher the ClO2 dosage, the lower the amount of DBPs produced. The amount of DBPs increased with reaction tim e, with chlorite ions as the primary inorganic by-product. (C) 2000 Elsevie r Science B.V. All rights reserved.