1. Use of Oxidants to Improve Contaminant Remediation
Spring Celebration
Use of Oxidants to Improve Contaminant Remediation
David L. Sedlak, Ph.D.

2. Project Team David Sedlak (CEE) Fiona Doyle (MSE)
David Waite (Univ. of New South Wales)
Christy Keenan
Ahn Pham

3. Oxidative Treatment Technologies
Motivation
Recalcitrant polar contaminants (e.g., NDMA)
Hydrophobic contaminants (e.g., PCBs)
Passive treatment (e.g., As in groundwater)

4. Oxidative Treatment Technologies
Motivation
Recalcitrant polar contaminants (e.g., NDMA)
Hydrophobic contaminants (e.g., PCBs)
Passive treatment (e.g., As in groundwater)
Limitations
Requires unstable reagents (e.g., H2O2)
Hydroxyl radical is unselective

5. Fe Nanoparticles as Reductants
Currently used for contaminant reduction
Zhang (2003)

6. Fe Nanoparticles as Oxidants
Oxygen activation during Fe corrosion
Fe0(s) Fe2+
2H+
Fe0(s) Fe2+ O2
O22-
H2O2
H2O
Fe2+ .
Fe3+ + OH- OH
OH- .
RH R
oxid

7. Oxidation of Molinate by Fe Nanoparticles
air
Joo et al. (2004) O2

8. Oxidation of As(III) by Fe
As(III) oxidation and As(V) adsorption
Leupin & Hug (2005)

9. Oxidation of As(III) by Fe
Selective As(III) oxidation
Hug and Leupin (2003)

10. Oxidative Remediation with Iron
Fe can convert O2 into a powerful oxidant
Potential for selective oxidation on surface
Potential applications
Passive treatment barriers
Soil and groundwater treatment
Drinking water treatment