Abstract
Mutagenic activity of leachate from a municipal solid waste landfill was surveyed with reference to clarification treatment by means of the Ames Salmonella assay. Mutagenicity for TA98 without metabolic activation by S9 was observed among 29% of raw leachate samples, whereas the mutagenicity rate was increased up to 72% in effluent water samples from a pre-aeration tank where leachate was received ca. 12 h of preliminary aeration. Further treatment of leachate by contact aeration, coagulation-sedimentation, sand filtration, and chlorination did not alter the mutagenicity rate as a mean. Effluent water from pre-aeration tank, however, did not show any increase in mutagenicity when no aeration took place, suggesting that the increase in mutagenicity in leachate at the pre-aeration tank was due to the aeration of leachate. Further investigation showed that mutagens could be removed during treatment on several occasions. This result indicates a possibility of establishing effective treatment to remove mutagens from landfill leachate.
