BROMINE INCORPORATION FACTORS FOR TRIHALOMETHANE FORMATION FOR THE MISSISSIPPI, MISSOURI, AND OHIO RIVERS

The bromine incorporation factor describes the distribution of the fou r trihalomethane compounds in the mixture formed when a natural water is chlorinated. This factor was determined for the Mississippi, Missou ri, and Ohio Rivers by chlorinating water samples at three levels each of pH and free chlorine concentration. Samples were collected during the summer, fall, and spring seasons of the year at 12 sites on the Mi ssissippi River from Minneapolis, MN, to New Orleans, LA, and on the M issouri and Ohio Rivers 1.6 kilometers upstream from their confluences with the Mississippi. The bromine incorporation factor increased as t he bromide concentration increased, and decreased as the pH, initial f ree-chlorine and dissolved organic-carbon concentrations increased. Va riation; of the bromine incorporation factor with distance along the M ississippi River approximately paralleled the variation gf the bromide concentration with distance along the river, with the Missouri River samples having the highest bromine incorporation factors for all combi nations of pH and free-chlorine concentration.