Occurrence and removal of free estrogens, conjugated estrogens, and bisphenol A in manure treatment facilities in East China

The occurrence of four free estrogens, four conjugated estrogens, and bisphenol A (BPA) was investigated in three cow farms, four swine farms, and five chicken farms. The daily total estrogen (free and conjugated) excretions of a cow were 145.23-179.27μg/d mainly through feces (92%), while swine excreted 42.56-219.25μg/d of estrogens mainly through urine (98-99%). Estrogen conjugates contributed 14.6-48.8% to the total estrogen excretions in cow feces and more than 98% in swine urine. A chicken excreted 0.66-12.78μg/d of total estrogens through feces, among which 34.2-100% was contributed by conjugated estrogens. The total estrogen removal efficiencies of manure anaerobic digesters and composters were 14.7-21.8% and less than 70.1%, respectively. Estrogens (E1, 17β-E2, E1-3S, and E2-3S) still existed in treated manure at concentrations up to 2695±181ng/L (anaerobic digestate) and at contents up to 80.8±6.0ng/g (compost). BPA was found in feces and compost samples at similar contents (nd-25ng/g), and approximately 60-70% of BPA was removed in wastewater treatment facilities.