Increased Chloroform Production from Model Components of Aquatic Humus and Mixtures of Chlorine Dioxide/Chlorine

The addition of aqueous solutions of chlorine and chlorine dioxide mixtures to model aqueous humus components showed that increased levels of chloroform production can be observed from some systems (i.e., 2,4- and 3,5-dihydroxybenzoic acids, 2,4,6-trihydroxybenzoic acid, and 3,5-dimethoxybenzoic acid). A detailed study of the reaction pathway for 2,4-dihydroxybenzoic acid was performed after it was observed that, under the identical reaction conditions, resorcinol gave the same product distribution. This observation suggested that the chloroform enhancement was due to a chlorine dioxide mediated decarboxylation and subsequent degradation pathway involving a hydroxybenzoquinone that was commnn both to 2,4-dihydroxybenzoic acid and to resorcinol. On the basis of differing product distributions, there appeared to be no commonality in the pathways for increased chloroform production for the 2,4- and 3,5-dihydroxybenzoic acids.