Projects per year
Abstract
Flocculation of small particulates suspended in solution is a key process in many industries, including drinking water treatment. The particles are aggregated during mixing to form larger aggregates, known as flocs, through use of a polyelectrolyte flocculant. The flocculation of these particulates in water treatment, however, are subject to a wide spatial variation of hydrodynamic flow states, which has consequences for floc size, growth rate, and microstructure. Floc assembly dynamics are explored here using a commercially available cationic polyacrylamide, commonly used in water treatment, and anisotropic Na-bentonite clay particles under a variety of hydrodynamic mixing conditions. A Taylor-Couette cell with the unique ability to radially inject fluid into the rotating annulus was used to study how specific hydrodynamic flow fields affect assembly and structure of these materials during the flocculation process. Faster floc growth rates and decreased floc fractal dimensions were observed for higher order flow states, indicating improved mass transfer of the polymer flocculant and breakage at the edges of the flocs (shear rounding), respectively. This work sheds more light on the complexities of polymer-induced flocculation, towards improving dosing and efficiency of large-scale operations.
Original language | English (US) |
---|---|
Pages (from-to) | 8627-8635 |
Number of pages | 9 |
Journal | Soft Matter |
Volume | 14 |
Issue number | 42 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Funding Information:Acknowledgment is made to the donors of the America Chemical Society Petroleum Research Fund for support of this research. This work was also partially supported by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-1420013. Part of this work was carried out in the College of Science and Engineering Polymer Characterization Facility, University of Minnesota, which has received capital equipment funding from the NSF through the UMN MRSEC program under Award Number DMR-1420013. A. M. was supported through a National Science Foundation Graduate Research Fellowship. N. W. was supported by the Department of Defense, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168a. The authors would like to thank Lisa Zeeb for designing the graphical abstract and experimental set-up figure.
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
How much support was provided by MRSEC?
- Partial
Reporting period for MRSEC
- Period 5
PubMed: MeSH publication types
- Journal Article
Fingerprint
Dive into the research topics of 'In situ polymer flocculation and growth in Taylor-Couette flows'. Together they form a unique fingerprint.-
MRSEC IRG-3: Hierarchical Multifunctional Macromolecular Materials
Reineke, T. M., Bates, F. S., Dorfman, K., Dutcher, C. S., Hillmyer, M. A., Lodge, T., Morse, D. C., Siepmann, I., Barreda, L. & Ganewatta, M. S.
1/1/98 → …
Project: Research project
-