Submitted to: Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2006
Publication Date: 12/6/2006
Citation: Shappell, N.W., Billey, L.O., Forbes, D., Poach, M.E., Matheny, T.A., Reddy, G.B., Hunt, P.G. 2007. Estrogenic activity and steroid hormones in swine wastewater processed through a lagoon constructed-wetland system.. Environmental Science and Technology 41(2):444-450. Interpretive Summary: Hormonal activity in livestock waste and treated wastewater releases is of interest because of intense livestock production practices. A lagoon, constructed wetland system was evaluated for efficacy in removal of estrogenic activity from swine wastewater at a swine birthing facility. Estrogenic activity was determined in a assay referred to as an E-Screen, that uses cells that will grow only in the presence of an estrogenic compound. The most estrogenic natural compound, ' 17-estradiol (E2), and the male reproductive hormone testosterone were measured by chemical analyses. Wetlands are typically used to reduce nutrient content of wastewater, so nutrient removal (reduction in nitrogen and phosphorus content of wastewater) was measured to ensure that the wetlands were functioning in a manner commonly reported in the literature. Samples, manure pit to the wetland outlet, were collected in April, July, and November of 2004, and weekly in July of 2005. Wetlands reduced estrogenic activity 83-93%. Nutrient removals were typical for treatment wetlands; nitrogen 59-75%, and orthophosphate (a form of phosphorus) 0-18%. Expected seasonal differences were observed (limited data). The greatest decrease in estrogenic activity and nitrogen was found with passage through the wetlands in November ’04. Good agreement was found between the E-screen values and the equivalent concentrations determined by chemical analyses. The most persistent estrogenic compound was identified as estrone, a breakdown product of estradiol. Constructed wetlands were effective in producing water with estrogenic activity below the lowest equivalent E2 concentration known to have an effect.
Technical Abstract: Anaerobic lagoons and treatment wetlands are used world-wide to treat wastewater from dense livestock production facilities. However, there is very limited data on the hormonal activity of the wastewater effluent produced by these treatment systems. The objectives of this experiment were to measure 1) the hormonal active of the initial effluent and 2) the effectiveness of a lagoon-constructed wetland treatment system for producing an effluent with a low hormonal activity. Wastewater samples were taken from the manure pit to the wetland outlet in April, July, and November of 2004 in a lagoon-constructed wetland system at a swine farrowing facility. Estrogenic activity (in vitro E-screen assay), ' 17-estradiol (E2) and testosterone concentrations (LC MS-MS) were measured. A high correlation was found between estradiol equivalents determined by E-Screen and LC MS-MS (R2 = 0.82). Nutrient removal was measured to ensure that the wetlands were functioning in a manner commonly reported in the literature. Nutrient removals were typical for treatment wetlands; TKN 59-75%, and orthophosphate 0-18%. Wetlands decreased estrogenic activity 83-93%. The greatest decrease in estrogenic activity was found with passage through the wetlands in November ’04. Estrone was the most persistent estrogenic compound. Constructed wetlands were effective in producing effluents with estrogenic activity below the lowest equivalent E2 concentration known to have an effect (10 ng/L or ~37 X 10-12 M).