Water and sediment samples from Lake Bonney (south-eastern South Australia) were
collected at various distances from the effluent discharge point of a sulfite-based pulp
mill and analysed for chlorophenolic compounds. The period of sample collection (July
1991 to January 1992) occurred during a time when bleaching process of the mill was
being converted from using molecular chlorine to using hydrogen peroxide. In water
samples, the major chlorophenolic compounds detected were 2,4,6-trichlorophenol,
tetrachlorocatechol and chlorinated guaiacols. In sediment samples, the major
chlorophenolic compounds detected were chlorinated guaiacols and chlorinated
catechols. The concentrations of these compounds in lake water generally decreased
over the sampling period, corresponding to the decrease in use of molecular chlorine.
Concentrations in sediment decreased with increasing distance from the discharge point.
The presence of chlorinated guaiacols in water and sediment at a site 17 km from the effluent
discharge point indicated that these compounds degrade slowly in the lake.
The presence of the chlorinated catechols in sediments at localities where these compounds
were not detected in the water suggests that de-0-methylation of adsorbed chlorinated guaiacols
occurs and/or that there is preferential adsorption of chlorinated catechols to sediment.
Hydroxylation and dechlorination of chlorinated guaiacols and syringols by Rhodococcus chlorophenolicus.
