Toxicity and bioconcentration potential of adsorbable organic halides from bleached laundering in municipal wastewater

A study was conducted to assess the formation, biological treatability, toxicity, and bioconcentration potential of adsorbable organic halides (AOX) formed from the use of household bleach during laundering. Following treatment with a bench-scale activated sludge system, approximately 70% of the laundry AOX was removed from the wash water. Removal efficiency of AOX from typical domestic wastewater treated in the same manner was 54%. Chronic bioassays conducted with the treated bleached laundry wash water effluent resulted in no toxicity to fathead minnow or Ceriodaphnia dubia that could be attributed to laundry AOX, even at concentrations 40 times higher than the predicted environmental AOX concentration. Analysis of treated bleached laundry effluent for bioconcentratable organic compounds tentatively identified no bioconcentratable or lipophilic chlorinated hydrocarbons in the treated laundry wash water.