FORMATION AND DISTRIBUTION OF HALOACETIC ACIDS, THM AND TOX IN CHLORINATION OF BROMIDE-RICH LAKE WATER

Lake Kinneret (Lake Galilee) water has a high bromide content that affects the chlorination process. Disinfection by products (DBP) of highly chlorinated lake water were studied. By combination of GC-MS and HPLC, six haloacetic acids, in which four of them containing bromine, were identified. Tribromo, dibromochloro, and bromochloro acetic acids were found for the first time in high concentrations in chlorinated surface water. Total haloorganic (TOX) formation per unit carbon was low compared with other water sources. THM and dihaloacetic acids formation per unit carbon were in the common, reported ranges, trihaloacetic acids and unidentified TOX had low yields of formation. The TOX was characterized by a high fraction, over 50%, of THM. The identified THMs and haloacetic acids accounted for about 75% of TOX. Brominated species constituted over 85% of the THMs and haloacetic acids. Tribromoacetic acid was found to undergo decomposition to form bromoform. This distribution of the TOX was the result of the following factors: (1) efficiency of bromination process compared with chlorination, (2) high content of aliphatic precursors and (3) decomposition of tribromoacetic acid to bromoform.