Toxicity of selected RCRA compounds to activated sludge microorganisms

A modified OECD Method 209, "Activated Sludge, Respiration Inhibition Test," was applied to 33 com pounds on the RCRA list that have been found in municipal wastewaters. Fifteen of the compounds had EC50 values (concen trations reducing the oxygen consumption rate to 50% of the control) less than 1000 mg/L or below their solubility limit if it was lower. Seven had EC50 values greater than 1000 mg/L, and 11 had EC50 values in excess of their solubility limits. The use of dimensionless inhibition plots revealed that many of the inhibitory compounds could be characterized by simple linear, reversible, inhibition models./ Water Pollut. Control Fed., 60,1850(1988).