Disinfection Byproduct Formation and Fractionation Behavior of Natural Organic Matter Surrogates

While natural organic matter (NOM) surrogates are established in disinfection byproduct (DBP) research, their use in fractionation studies is rare. To understand how surrogates relate to drinking waters, a range of NOM surrogates were fractionated with XAD resins. Their trihalomethane (THM), haloacetic acid (HAA), haloacetaldehyde, haloacetonitrile, and haloketone formations after chlorination were recorded. While compounds with higher log K-ow values behaved as hydrophobic acids, fractionation of the more hydrophilic compounds did not clearly correlate to the log Kow. High HAA formation from ferulic and aspartic acids and 1,1,1-trichloro-propanone (1,1,1-TCP) formation from 3-oxopropanoic acid were notable. Three amino acids, asparagine, aspartic acid, and tryptophan, formed significant levels of dichloroacetonitrile (DCAN) and trichloroacetaldehyde (TCA). Formation of DBPs did not correlate to any compound physical property, however, there were several correlations between DBP groups. The most significant were between dichloroacetic acid (DCAA) and dichloroacetonitrile (DCAN), DCAN and TCA, and dichloroacetaldehyde (OCA) and trichloroacetaldehyde, indicating the possibility of similar relationships in natural waters.