Influence of Humic Water Substances on the Degradation of PAH During Water Chlorination

14C-labelled benzo(a)pyrene (BaP) was added to three types of water samples a) bog water, b) lake water and c) artificial water. After equilibration the samples were chlorinated with NaOCl solution under buffered conditions. After 72 h BaP and degradation products were extracted consecutively with CH₂ Cl₂ at neutral pH then at acidic pH and finally by absorption to XAD-2. The extracts were subjected to fractionation by reverse-phase HPLC.In contrast to the artificial water about 20% of the reaction products could not be extracted from the humic water samples. This might either be due to formation of more water soluble degradation products in the presence of humic matter or strong complexation of these products to humus. On the other hand, no significant difference in the reaction product profile is. observed in the neutral CH₂ Cl₂ extract of neither of the three water samples, i.e. humus has no effect on the distribution of reaction products in this fraction.