BIOCHEMICAL AND CHEMICAL DEGRADATION OF CHLORO-4-(DICHLOROMETHYL)-5-HYDROXY-2(5H)-FURANONE (MX) IN SURFACE AND DRINKING-WATER

Microbiological and chemical degradation of the strong mutagen chloro- 4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in drinking and surfa ce water samples was studied using C-14 labelled MX. The degradation w as measured as production of (CO2)-C-14, and as amount of C-14 radioac tivity incorporated into microbial biomass. The rate of chemical (CO2) -C-14 production exceeded the rate that associated with microbiologica l activity, and was higher at pH 8 than at pH 5.5. At pH 5.5 there was a slight biotic production of (CO2)-C-14 both in drinking and surface water samples. The amount of C-14 derived from MX incorporated into m icrobial was 0 to 0.2 % from the added C-14-MX. The rate of chemical ( CO2)-C-14 production was lower in surface and drinking waters than in demineralized water. Even 21 % of the labelled carbon volatilized from the water samples as some unknown compounds. The results indicated th at humus material might protect MX against abiotic degradation.