Fate of indicator endocrine disrupting chemicals in sewage during treatment and polishing for non-potable reuse

摘要

The removal and fate of several indicator endocrine disrupting chemicals (EDCs) at two largenmunicipal wastewater treatment plants (WWTPs) in Adelaide South Australia was investigated.nNon-estrogens included the non-ionic surfactant breakdown compounds nonyl phenol monoandndi-ethoxylates, 4-t-octylphenol and 4-nonyl phenol; and, the plasticizer bisphenol A. Estrogensnincluded 17b-estradiol; estrone; and, 17a-ethynylestradiol. Effluent from Bolivar WWTP isnpolished using stabilisation lagoons followed by coagulation, dissolved air flotation/filtration andnchlorination for non-potable reuse. Biosolids from both plants is applied to agricultural landnas a soil conditioner. Non-estrogen indicator EDCs were detected at the highest concentration innsewage, effluent and sludge but estrogen indicator EDCs contributed the greatest potential fornestrogenicity. The fate of indicator EDCs at various treatment stages is complex and includesnbiochemical modification/transformation and/or partitioning to either solid or liquid phases.nActivated sludge treatment was an important removal barrier achieving moderate—highnremoval of predicted and YES (a yeast screen assay) measured estrogen equivalent values (EEq).nCombined polishing treatment achieved high removal of candidate EDCs (97%). Mass balancenindicates that the largest source of estrogenicity discharged from both WWTPs investigatednis digested sludge which accounts for 18 and 22% respectively of the combined predicted andnYES measured EEq measured in sewage at the two WWTPs.