Probing the mechanisms of NOM chlorination using fluorescence: formation of disinfection by-products in Alento River water

Experiments with Alento River water (a drinking water source in the province of Salerno, Italy) showed that considerable amounts of disinfection by-products, primarily chloroform and haloacetic acids, form in that water upon chlorination. The total yield of haloacetic acids was almost twice as high as that of chloroform. Chlorination also caused significant changes in the intensity of NOM fluorescence and the position of the emission band. To quantify the latter, the wavelength that corresponds to the position of the emission band at its half-intensity (2,lambda(0.5)) was employed. Chlorination caused the,,, values to decrease, while the THMs and HAAs concentrations were linearly correlated with the corresponding lambda(0.5) values. The strength of correlations between DBP concentrations and lambda(0.5) values indicates that the latter parameter can be employed in studies of DBP formation in drinking water.