Biotransformation of Pharmaceuticals and Personal Care Products (PPCPs) during Nitrification: The role of Ammonia Oxidizing Bacteria Versus Heterotrophic Bacteria

摘要

Preliminary experiments to investigate the fate of 17α-ethinylestradiol (EE2)during nitrification were conducted. Sorption experiments were performed byincubating inactivated ammonia oxidizing bacteria and various heterotrophic culturesin the presence of ~(14)C-EE2 at 10 μg/L. Biotransformation experiments utilized LCMSand LC-ITMS analysis of supernatant collected during batch cultivation ofmonoculture of Nitrosomonas europaea with EE2. Results confirmed that sorption ofEE2 onto heterotrophic biomass is an important mechanism that must be consideredwhen describing the fate of EE2. During batch incubation with N. europaea, 98% ofEE2 was transformed, producing a unique metabolite corresponding to a mass/chargeratio of - 386 m/z. Short term inhibition study results also suggest that inhibition ofrespiration in N. europaea as measured through nitrite generation rates is notsignificant at concentrations at or below 1 mg EE2/L.