The Toxicity of Organic Chemicals to Treatment Processes

Abstract

The IC50 concentration was determined for a common set of narcotic chemicals to three classes of environmental organisms - aerobic heterotrophs, methanogens and Nitrosomonas as well as to MicrotoxR. The toxicity was well modeled using the linear solvation energy relationship which incorporates molecular volume, polarity/polarizability, hydrogen bond donor acidity and hydrogen bond donor basicity. Chemical characteristics which contribute to a chemical's toxicity are discussed. The relative toxicity to these different classes of environmental microorganisms is discussed and the implications to biological treatment process stability are considered.