REACTIONS OF PAH WITH CHLORINE AND CHLORINE DIOXIDE IN COAL-TAR LINEDPIPES

In presence of disinfectants, PAH are remobilized from the coal tar li ning of water distribution mains. Reactions of the PAH with chlorine a nd chlorine dioxide can lead to chlorinated PAH that might show higher mutagenic effects than the parent PAH. The application of the solid-p hase micro extraction as a sampling preparation method in combination with a gas chromatographic mass spectrometric device is a reliable and useful method to achieve detection limits in the lower nanogramme-per -liter level for PAH and chlorinated PAH. Thus, the reactions of four PAH (anthracene, fluoranthene, fluorene, and phenanthrene) with chlori ne and chlorine dioxide under conditions prevalent in drinking water d istribution systems could be investigated. In batch experiments with d emineralized and drinking water at pH 7, the concentrations of fluoran thene, fluorene, and phenanthrene remained constant, whereas anthracen e reacted quantitatively with both disinfectants. In these reactions, no chlorinated products could be detected, only monohydroxyanthracene and anthraquinone were formed. A reaction mechanism for both reaction products is proposed. The results suggest that oxidation is the major pathway of the reaction of PAH with disinfectants in the systems under investigation.