Discipline: Chemistry and Chemical Sciences
Subcategory: Materials Science
Dion Casey - Saint Augustine University
Co-Author(s): Cari Dutcher, Athena Matexas, and Nikolas Wilkinson, University of Minnesota
Flocculation is the process in water treatment that aggregates and sediments suspended particulates before filtering, generally using cationic polymers that complex to the surface of anionic particles. Controlling the polymer behavior in flocculation is critical for many applications including, composite material, paper manufacturing, and water treatment. Flocculation behavior is dependent on many parameters including particulate identity, zeta potential, solution pH, ionic strength, and local hydrodynamics. Flocculation performance (final turbidity) was measured as a function of ionic strength and polymer charge percent, at a constant pH of 6.6, hydrodynamic profile, and bentonite concentration of 30 mg/L. The charge percents tested were 1.5%, 10%, 20% and 60%. Increasing ionic strength reduced the optimum polymer dose for all polymer charge percent tested, due to an increase in initial bentonite aggregate size and reduction in electrostatic repulsion. Increasing the polymer charge percent decreased the optimal polymer dose. This work sheds light on the complexities of polymer flocculation towards improving reagent polymer dosing and treatment optimization for important applications such as water purification.
Funder Acknowledgement(s): This work was supported partially by the Research Experiences for Undergraduates (REU) Program of the National Science Foundation under Award Number DMR-1559833 and DMR-1420013.
Faculty Advisor: Cari Dutcher, cdutcher@umn.edu
Role: Ran Flocculation test of 1.5%, 20%, 605 and 80%. Independently I used the flocculators to create a flocculation simulation of only 100mL of Distilled Water. Also used the AFM microscope to image the anisotropic particle bentonite.