Principal Investigator
Dr. Michael Sander – Eawag / ETH Zurich
Collaborators
Dr. Thomas Hofstetter– Swiss Federal Institute of Aquatic Science and Technology (Eawag)
Dr. Juliane Hollender– Swiss Federal Institute of Aquatic Science and Technology (Eawag)
Heinz Singer– Swiss Federal Institute of Aquatic Science and Technology (Eawag)
Dr. Hans Peter Arp– Norwegian Geotechnical Institute (NGI)
Dr. Andrea Gredelj– Norwegian Geotechnical Institute (NGI)
Dr. Raoul Wolf– Norwegian Geotechnical Institute (NGI)
Description
The first comprehensive assessment of adsorption and desorption characteristics of water soluble polymers (WSPs) and water dispersible polymers (WDPs) to mineral surfaces for environmental fate assessment was recently published by the group of the principal investigator (Sanders et. al) . In this work, the adsorption-desorption characteristics of six WSPs (including positively- and negatively charged modified dextrans, negatively charged polyacrylic acid, positively charged polylysine, and uncharged, polar polyethylene glycol (PEG) and dextran) to two mineral surfaces (i.e., silica sand and iron-oxide coated silica sand) were systematically studied under varying solution pHs and ionic strengths. Adsorption to particles was studied in well-mixed batch reactors and during transport in sorbent-filled columns. These analyses were complemented by in-situ surface adsorption experiments (i.e., quartz crystal microbalance with dissipation monitoring (QCM-D) and optical waveguide light mode spectroscopy (OWLS)), to obtain insights into the conformations of adsorbed polymers. This study was instrumental in drawing mechanistic conclusions mentioned above and provides the conceptual and experimental basis for the work proposed herein. This project will make use of the existing experimental sets up and ensuring efficient transferability to the following project objectives:
- Conduct systematic laboratory investigation on the adsorption ad desorption characteristics of WS/DPs to identify the forces driving adsorption/desorption and to parameterize the rates and extents of adsorption.
- Advance a detailed understanding of (and theory for) WS/DPs adsorption to solid-water interfaces present in engineered and natural systems under consideration of commonalities and dissimilarities of WS/DP adsorption characteristics with those of low molecular weight organic chemicals and solid colloids.
- Provide science-based advice on and engage in the communication of WS/DP adsorption as a key process controlling the fate of these polymers upon release into natural and engineered systems.
