Wednesday, February 26, 2020

Speaker: Bas Vriens, Assistant Professor, Queen’s University

Title: "Stinking rich: gold-laden sewage"

Time: 2:00 PM

Location: Rm. 351, Mitchell Hall



I joined the Geology department last fall; my GeoEnvironmental Engineering group is sparkling new. Originally from the Netherlands, I did my undergraduate in Chemical Engineering and then a MSc in Earth Sciences (Utrecht University). My PhD is from ETH Zurich - focused on global biogeochemical cycles of trace elements. I worked at the Swiss Federal Institute of Aquatic Science and Technology (EAWAG) after that and had a brief stint in consulting also. Before coming to Queen’s, I was a postdoctoral research and teaching fellow at UBC Vancouver for 2 years, and worked on metal mobilization from mine wastes.



The numbers and quantities of trace metals used in the energy and communication sectors, consumer electronics and chemical and pharmaceutical industries are increasing exponentially, but corresponding waste streams and environmental impacts remain poorly quantified. In this talk, I will first present results from a nationwide survey of wastewater treatment facilities in Switzerland, in which we assessed the concentrations of >60 (trace) elements. This data set, representative of an entire industrialized country, presented a first baseline reference for current trace metal concentrations, average per-capita fluxes, loads discharged to surface waters, and economic waste-stream values. Geospatial analysis and comparison of effluent loads from wastewater treatment plants with Swiss riverine fluxes indicated dominant anthropogenic sources for a variety of trace metals: examples include Gd from its medical application as a contrast agent, Ce (nano)particles used in polishing emulsions as well as various valuable precious metals… Currently, my research group at Queen’s University works on establishing environmental budgets for trace metals in Canada, focusing on the Great Lakes and the St. Lawrence drainage basin. We collaborate with industry and government partners and use a combination of large-scale screenings, geospatial statistics and site-specific on-site sampling to quantify emissions of trace metals through wastewater effluents. The results of this project may have significant practical implications, ranging from the prioritization of emerging metal contaminants in environmental policy, source-tracking of major societal and industrial emission pathways, as well as technological advances aimed at optimizing wastewater treatment for increased elimination or even recovery of valuable metals.

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