Parallel Factor Analysis of Excitation-Emission Matrices to Assess Drinking Water Disinfection Byproduct Formation During a Peak Formation Period

Parallel factor (PARAFAC) analysis was applied to the fluorescence excitation-emission matrices (EEM) of a water treatment plant's source and coagulated water during a peak chlorinated byproduct formation period. Water plant operations included the use of surface water only and surface/ground water mixtures. Three statistically significant components were obtained through PARAFAC analysis and were correlated to dissolved organic carbon (DOC), chlorine consumption, and individual disinfection byproduct (DBP) formation potential. Multifactor linear regression of select component scores showed linear relationships to individual chloro-DBP compounds providing insight to possible precursor locations within the EEM and organic matter, as well as, organic compound characteristics responsible for chloro-DBP formation. Likewise, linear relationships were also observed between component scores and empirically estimated precursor concentration methods reported in the literature. These results suggest PARAFAC analysis of EEM may be an effective tool for monitoring source water, measuring treatment process effectiveness (removal of specific DBP precursor), and estimating DBP precursor concentrations and individual DBP compound formation potential.