Astani Civil and Environmental Engineering Ph.D. Seminar

Speaker: Dr. Christopher Higgins, Colorado School of Mines

Talk Title: Passive technologies for treatment of urban stormwater: Biochar-amemnded bioinfiltration systems and biohydrochemically enhanced stream-water treatment

Abstract: Despite substantial water quality challenges associated with urban stormwater, stormwater managers typically prioritize storm flow reduction rather than pollutant removal. Common stormwater pollutants of concern can vary greatly by region, but often include nutrients, metals, pathogens, and trace organic chemicals. In this seminar, two novel technologies for removal of chemical contaminants from stormwater will be discussed. Bioinfiltration systems have shown potential to afford dual benefits of preventing contamination of urban receiving waters while augmenting urban water storage. The addition of a black carbon sorbent (biochar) to these systems may be especially effective for enhanced removal of traceorganic chemicals (TOrCs). Efforts to calibrate and verify a forward model for intraparticle diffusion-limited TOrC transport will be discussed, as well as the potential for transformation product generation in these systems. Further, a novel approach for treating stormwater while conveying it will be presented. This approach, termed Biohydrochemical Enhancement structures for Streamwater Treatment, BEST, relies on subsurface modifications to streambed hydraulic conductivity to drive efficient hyporheic exchange. When coupled with subsurface geomedia enhancements, BEST modules show significant promise for treating urban stormwater contaminants with minimal impacts to other stream functions. Together, these passive technologies suggest that the enhancement of natural processes in urban water infrastructure may have significant benefits to urban water quality.


Biography: Dr. Christopher P. Higgins is an Associate Professor in the Department of Civil and Environmental Engineering at the Colorado School of Mines. Dr. Higgins earned his PhD and MS from Stanford in Civil and Environmental Engineering, and his BA from Harvard in Chemistry and Chemical Biology. Before joining the faculty of CSM in 2009, he completed a postdoctoral appointment at Johns Hopkins. His research focuses on the movement of contaminants in the environment. In particular, he studies chemical fate and transport in natural and engineered systems as well as bioaccumulation in plants and animals. Contaminants under study in his laboratory include poly- and perfluoroalkyl substances used in stain-repellent fabrics and firefighting foams, nanoparticles, wastewater-derived pharmaceuticals and personal care products, trace organic chemicals in urban stormwater, and trace metals.

Host: Dr. Daniel McCurry