Effects of Liquid Swine Manure On Sorption of 17ß-Estradiol to Soil.

Estrogens are potent endocrine disrupting chemicals and can be found in the environment. Animal manure can contain estrogenic hormones, specifically 17b-estradiol (E2). A common manure management practice is to contain liquid manure in a manure storage ponds or lagoons, which is then applied on or injected into the land surface. Laboratory studies have demonstrated that E2 binds readily and strongly to soil and biodegrades within hours. However, several field studies have frequently detected E2 in the environment, which suggest moderate mobility and persistence. Therefore, it was hypothesized that E2 binds to colloidal organic carbon (COC) and dissolved organic carbon (DOC) within the lagoon manure, which may facilitate its mobility and perhaps its persistence. The objective of this study was to determine if COC and DOC from lagoon manure affect the sorption and potential mobility of E2 in soil. Batch experiments were used to determine the sorption distribution of E2 in soil with lagoon waste solution and compared to batch experiments conducted with only a 0.1M CaCl₂ solution. A series of batch experiments were made up of four concentrations of ¹⁴C labeled E2 (ranging from 0.01-0.7 µCi per vial) and two sterile soils of identical texture but different organic carbon contents (1.35 and 0.32%).  Batches vials were rotated, sampled at nine set time points (0.17, 0.33, 1, 2, 3, 7, 14, 21, 28 days) for liquid scintillation counting (LSC) and thin layer chromatography analysis. To determine what manure organic carbon fraction (i.e., DOC or COC) that E2 preferentially associated with, a lagoon sample spiked with ¹⁴C E2 was run through a 1.5µm filter and a 1kD ultrafilter. The filtrate was sent to LSC for quantifying ¹⁴C E2 amounts.