Effects of Hardness, Alkalinity and pH on the Toxicity of Pentachlorophenol to 'Selenastrum Capricornutum' (Printz)

摘要

The toxicity of pentachlorophenol (PCP) to Selenastrum capricornutum was examined in three different culture media: a hard and a soft form of Freeman's reference water and the algal assay bottle test (AABT) medium (a soft water). The 96-h growth potentials of the media were equal (28-29 mg/L dry wt.) but 96-h EC50s ranged sevenfold: 0.11 mg/L (AABT), 0.15 mg/L (Freeman's soft water) and 0.76 mg/L (Freeman's hard water). Culture media equilibrium pH and 96-h EC50s were strongly correlated (r=1.00). Evidence is presented that supports the hypothesis that the toxicity of PCP, a weak acid, is due primarily to the concentration of the undissociated species.