TRIHALOMETHANE AND NONPURGEABLE TOTAL ORGANIC-HALIDE FORMATION POTENTIALS OF THE MISSISSIPPI RIVER

Trihalomethane and nonpurgeable total organic-halide formation potenti als were determined for water samples from 12 sites along the Mississi ppi River from Minneapolis, MN, to New Orleans, LA, for the summer and fall of 1991 and the spring of 1992. The formation potentials increas ed with distance upstream, approximately paralleling the increase of t he dissolved organic-carbon concentration. The pH and the dissolved or ganic-carbon and free-chlorine concentrations were significant variabl es in the prediction of the formation potentials. The trihalomethane f ormation potential increased as the pH increased, whereas the nonpurge able total organic-halide formation potential decreased. All formation potentials increased as the dissolved organic-carbon and free-chlorin e concentrations increased, with the dissolved organic-carbon concentr ation having a much greater effect.