Removal of estrogenic hormones from manure-containing water by vegetable oil capture

Manure-containing water (MCW) is frequently used for agricultural amendment, a practice that introduces natural and synthetic hormones to the environment. Advanced treatment processes are not practical for most animal operations, so inexpensively removing hormones from MCW by capture with vegetable oils was evaluated. Estrone (E1) and 17β-estradiol (E2) were used as model hormones due to their high biological activity and prevalence in MCW. Eight vegetable-based oils were able to remove >94% of E1 and >87% of E2 from nanopure water (NPW), and tested oils had log₁₀K_oil-water values of 1.96-2.66 for E1 and 1.51-2.47 for E2. System parameters were optimized at 3min of shaking time and 1:10 corn oil:water (v/v). Removal from real MCW and NPW was assessed at several initial concentrations of E1 and E2. While E1 removal was comparable across all initial concentrations and both water types (>93%), E2 removal exhibited concentration-dependent interaction with MCW matrix. Treatment capacity was assessed by using the same oil for multiple batches of NPW or MCW. After 18 cycles, removal dropped to 50-64% of E1 and 35-37% for E2. Treating MCW with vegetable oils may be a promising approach to inexpensively remove microcontaminants before MCW is used for land application.