Generation of halogenated organic compounds in municipal waste water

Abstract

Cleaning agents and disinfectants from housekeeping, hospitals and canteen kitchens are important sources of adsorbable halogenated organic compounds (AOX) in municipal waste water. They often contain inorganic compounds which are able to release activated chlorine. Together with organic waste water compounds the activated chlorine can generate halogenated organic compounds. Within the scope of this research project the generation of AOX through these active agents is compared. The effects of concentration, pH, time, temperature, presence of other oxidizing or reducing agents and synergetic effects are investigated and discussed.According to the results the potential of these active agents forming AOX is obvious. The AOX concentration of a municipal waste water increased by the factor of 13 after adding an hypochlorite containing disinfectant in common concentration. Most AOX can be formed within 30 minutes. In sewage with high amount of solid compounds the AOX generation can take a long time (several days). The amount of AOX generated strongly depends on the nature and concentration of dissolved and solid organic compounds, the concentration of active substances, temperature, pH and the reaction time.