Abstract

Discharge from wastewater treatment plants (WWTPs) is a point source for 17β-estradiol (E2) and estrone (E1) into surface water systems. This work examines the potential of three pilot-scale wetland designs, a subsurface flow (SSF), a surface flow (SF), and a floating aquatic plant (FAP), to remove E2 and E1 from effluent of a WWTP. None of the three designs completely removed E1 or E2 from the wastewater effluent. Mean E2 and E1 concentrations in the effluent ranged from 32.80 to 55.54 ng/L and 73.60 to 74.80 ng/L, respectively. The SSF design reduced E2 by 27% and the FAP design reduced E2 by 13%. The surface-flow design failed to reduce E2. Effluent E1 concentrations from the different systems were not statistically different from the influent E1 concentration. Adsorption of E2 and chemical transformation of E2 to E1 appears to be the removal mechanisms. An increase in E2 concentrations in the surface-flow system and a decrease of E2 in the FAP system suggest that plants are a factor in the removal of E2. However, evapotranspiration effects complicate the ability to discern the removal mechanism.

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