Northwestern Events Calendar

Nov
8
2019

SPREE Seminar: Dominic Frigon

When: Friday, November 8, 2019
2:00 PM - 3:00 PM CT

Where: Technological Institute, A230, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students

Contact: Tierney Acott   (847) 491-3257

Group: McCormick - Civil and Environmental Engineering (CEE)

Category: Lectures & Meetings

Description:

Microbial Immigration through the Urban Water Cycle: Importance for Process Modeling and System Dynamics Prediction

Abstract:
The wastewater industry is under increasing pressure to meet ever more stringent discharge regulations, improve water resource recovery, and expand removal of emerging contaminants. The diverse microbial communities found along the urban water cycle are fundamental for the engineering of biological processes to meet these challenges. However, current practices often neglect immigration between sections of the cycles; for example, from the sewer to the wastewater resource recovery facility. High-throughput amplicon sequencing now allows the detection of low abundance taxa, improving the description of the immigration process. With this approach, we analysed the impact of sewer immigration on the activity of nitrifiers, ordinary heterotrophs, and phosphate-accumulating organisms in full-scale and laboratory-scale activated sludge wastewater bioreactors. For nitrifiers, we demonstrated at full-scale plant the important and ecologically neutral transfer (i.e., without selection) of nitrifying populations between the sewer and the activated sludge system. Considering influent nitrifiers resulted in a 30% reduction of the maximum growth rate used to model the activated sludge, which could correspond to an equivalent reduction in plant size. At laboratory-scale, we confirmed that complete nitrification can be restored by sewer immigration in activated sludge system operated at SRTs below wash out. For heterotrophs, we showed that respirometry assays to assess biomass concentrations in wastewater influent overestimate immigration rates because the assays neglect ecological selection. In addition, immigration appears to impact more the populations consuming readily degradable substrates than slowly degradable substrates, suggesting complex ecological interactions among heterotrophs. These data will contribute to the site-specific optimization of wastewater resource recovery facilities, and to understand the significance of sewer systems in structuring activated sludge microbial communities.

 

Biography:
Dominic Frigon is an Associate Professor of environmental engineering in the Civil Engineering Dept. at McGill University (Montreal, Canada). He holds BSc and MSc degrees in Microbiology from McGill (Montréal) and a Ph.D. in Environmental Engineering from the University of Illinois (Urbana-Champaign). He specializes in biological wastewater treatment, organic resource recovery, and biosolids safety, with emphasis on the characterization of microbial communities with metagenomics and mathematical modeling. He directs a team of several Masters and Ph.D. students currently working on innovative systems for producing biomaterials and energy from waste, for limiting the dispersal of antimicrobial resistance, and for reducing excess biosolids while improving their microbiological qualities. Finally, his work also extends to sewer systems, where his team develops strategies to engineer sewer microbial communities and impact microbial activities inside wastewater resource recovery facilities.

 

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