UMass Amherst

John E. Tobiason

Professor, Dept. of Civil & Environmental Engineering
21 Marston Hall, University of Massachusetts
Amherst, MA 01003-9292
(413) 545-5397
tobiason@ecs.umass.edu
http://www.ecs.umass.edu/index.pl?id=3920&isa=Category&op=show

Colloids in Engineered and Natural Aquatic Systems

I am an Environmental Engineer with a research and teaching focus in many aspects of drinking water supply, treatment and distribution, as well as more fundamental interests in the characterization of particles, and processes at the particle-water interface, in aquatic systems.  Particles/colloids can be important contaminants, or carriers of contaminants, in aquatic systems, and can significantly impact the performance of engineered treatment systems. Many trace contaminants such as heavy metals and synthetic organics preferentially partition to solid surfaces so their fate and transport in the environment is often controlled by colloids. Also, human pathogens of various types (viruses, bacteria, protozoa) are “bio-particles” in terms of fate and transport.

Research Interest Potential Application
Improved characterization of sub-micron sized particles in water supplies Particle number concentrations in water supplies are dominated by sub-micron size particles.  Improved characterization is needed to optimize water treatment
Nano-particles for improved environmental remediation Engineered nano-particles have the potential to bring about improved sub-surface remediation due to high surface area, transport capability and custom surface property design

Publications

  1. Tobiason, J.E., “Chemical Effects on the Deposition of Non-Brownian Particles”, Colloids and Surfaces, Vol. 39, pp. 53-77, 1989.
  2. Nocito-Gobel, J. and Tobiason, J.E., “Effects of Ionic Strength on Colloid Deposition and Release”, Colloids and Surfaces A, Vol. 107, pp. 223-231, 1996.
  3. Edzwald, J.K., Tobiason, J.E., Amato, T. and Maggi, L.J., “Integrating of High Rate DAF Technology into Plant Design”, Journal American Water Works Association, Vol. 91, No. 12, pp. 41-53, 1999.
  4. Schneider, O.D. and Tobiason, J.E., “Effects of Preozonation on Coagulant/Particle/NOM Interactions”, Journal American Water Works Association, Vol. 92, No. 10, pp. 74-87, 2000.
  5. Tobiason, J.E., Edzwald, J.K., Gilani, V., Kaminski, G.S., Dunn, H.J. and Galant, P.B., “Effects of Waste Filter Backwash Recycle Operation on Clarification and Filtration”, Journal of Water Supply: Research and Technology – AQUA, Vol. 52, No. 4, pp.259-276, 2003.