The Fate of Estrogenic Hormones in an
Engineered Treatment Wetland with Dense Macrophytes
James L. Gray†
David L. Sedlak
Department of Civil and Environmental Engineering
University of California, Berkeley
Berkeley, CA 94720
† Current affiliation:
U.S. Geological Survey
Boulder, CO
Abstract
Recently, the estrogenic hormones 17beta-estradiol (E2) and
17alpha-ethinyl estradiol (EE2) have been detected in municipal
wastewater effluent and surface waters at concentrations sufficient to
cause feminization of male fish. To evaluate the fate of steroid
hormones in an engineered treatment wetland, lithium chloride, E2 and
EE2 were added to a treatment wetland test cell. Comparison of
hormone and tracer data indicated that 36% of the E2 and 41% of the EE2
were removed during the cell’s 84-hour hydraulic retention
time. The observed attenuation was most likely the result of
sorption to hydrophobic surfaces in the wetland coupled with
biotransformation. Sorption was indicated by the retardation of
the hormones relative to the conservative tracer.
Biotransformation was indicated by elevated concentrations of the E2
metabolite, estrone It may be possible to improve the removal
efficiency by increasing the hydraulic retention time or the density of
plant materials.