Mitigation of biological-active contaminants of emerging concern in urban stormwater utilizing Iron-enhanced sand filtration

Abstract

Presented by: Satomi Kohno – Assistant professor at St Cloud State University, skohno@stcloudstate.edu

Co-authors: James E. Gerads, Heiko L. Schoenfuss

Abstract: A variety of pollutants, including contaminants of emerging concern, are polluting urban stormwater. It is essential to reduce the level of pollutants before they are released into the environment. Both analytical chemistry and biological endpoints evaluated the mitigation potential of stagnant ponds and iron-enhanced sand filtration (IESF) in vivo and vitro. Inflow and effluent samples were collected from seven stormwater ponds in St. Paul, Minnesota, USA, metropolitan area in different seasons. Seasonal effects on pH, conductance, and total dissolved solids (TDS) of stormwater were identified, but there were no treatment effects at these endpoints. Seasonality affected the concentration of Nonylphenol, an estrogenic endocrine disruptor, in stormwater with a peak in spring, but no effect of treatment on nonylphenol concentrations. Treatment reduced Fathead minnow larval survival in exposures to stormwater collected in spring and summer, whereas consumption was affected by treatment in fall-collected stormwater exposures. In vitro exposure to stormwater, none of the sites or treatments affected estrogenicity in fathead minnows, bluegill, and largemouth bass. Still, we identified differences in cell viability between sites at 6 h exposure to stormwater. Potential mitigation of reservoirs for stormwater treatment varied by season, but the benefits of IESF were not evident in biological endpoints.

Biography: Aquatic Toxicology Laboratory, Saint Cloud State University 720 Fourth Avenue South, Saint Cloud, MN 56301, United States; 320-200-9173; skohno@stcloudstate.edu