ARS | Publication request: Fate of estradiol and testosterone in anaerobic lagoon digestors

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2008
Publication Date: August 17, 2008
Citation: Hakk, H., Larsen, G.L., Sikora, L.J., Casey, F.X.M. 2008. Fate of estradiol and testosterone in anaerobic lagoon digestors. AGRO Picogram v. 75 (AGRO 118).

Technical Abstract: Laboratory-scale lagoon digestors were constructed, and the fate of 14C-labelled 17ß-estradiol (E2) and testosterone (Test) were monitored for 42 d anaerobically under biological and sterile conditions. Hormone levels decreased in the liquid layer and increased in the sludge with time. At 42 d, 16-24% of the Test and 19-24% of the E2 remained in the liquid layer. E2 degraded to estrone, which rapidly sorbed to sludge, and a polar metabolite (possibly estriol), but formation of estrone also occurred under sterile conditions after 14 d. Many metabolites formed from testosterone under these conditions; degradation was biological and non-biological. Daily gas production was monitored. For Test, 3.5-10.7% was converted to methane, while for E2, 7.6-23.8% went to methane. CO2 mineralization was 0.5-1.4% of the Test dose, 0.3-0.5% of the E2 dose. Virtually no methane or CO2 was generated under sterile conditions. Based on these laboratory studies, it would be expected that despite 70-80% reduction in parent compound, by-product steroids were formed under anaerobic lagoon digestion, which may be a continuing concern as environmental endocrine disruptors, albeit to a lesser potency than the parent compounds. Therefore, coupling the anaerobic process to an aerobic process may serve to completely destroy the biologically active hormones.