Both industrially-impacted and domestic municipal sewage treatment plant wastewaters and sludges have been studied to isolate the residue organics for the characterization of their mutagenic properties and for the isolation/identification of the mutagenic components. Methods were investigated to isolate the residue organics for mutagenic assessment via the Salmonella/microsomal activation, i.e., 59, assay. Residue organics were isolated from wastewaters by a modification of the USEPA/EMSL-LV interim protocol for the isolation of residue organics from drinking water for mutagenic assessment. Residue organics were isolated from sludges via three methods: the Soxhlet extraction method of Hites; the USEPA/EMSL-CIN Method 624S/6255; and a newly-developed method in the study that features the milling of the sludge with anhydrous sodium sulfate to a homogeneous powder followed by sequential extractions using a solvent series from non-polar to polar. The residue organics from wastewaters and sludges were fractionated by high performance liquid chromatography (HPLC) using a coupled bioassay/analytical fractionation approach. In general, mutagenic assessment of the residue organics from the industrially-impacted treatment plant wastewaters and sludges show both direct acting and 59 dependent TA98 mutagenic activity.

Caption title. "November 1989." "EPA/600/1-89/007." "M. Kate Smith, project officer." "CR-810792." Microfiche.