Bromine incorporation factors for trihalomethane formation for the Mississippi, Missouri, and Ohio Rivers

The bromine incorporation factor describes the distribution of the four trihalomethane compounds in the mixture formed when a natural water is chlorinated. This factor was determined for the Mississippi, Missouri, 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 Mississippi River from Minneapolis, MN, to New Orleans, LA, and on the Missouri and Ohio Rivers 1.6 kilometers upstream from their confluences with the Mississippi. The bromine incorporation factor increased as the bromide concentration increased, and decreased as the pH, initial free-chlorine and dissolved organic-carbon concentrations increased. Variation of the bromine incorporation factor with distance along the Mississippi River approximately paralleled the variation of the bromide concentration with distance along the river, with the Missouri River samples having the highest bromine incorporation factors for all combinations of pH and free-chlorine concentration.