Spring Celebration

David L. Sedlak, Ph.D.

sedlak@ce.berkeley.edu

http://www.ce.berkeley.edu/~sedlak/

Use of Oxidants to Improve Contaminant Remediation

Project Team

• David Sedlak (CEE)

• Fiona Doyle (MSE)

• David Waite (Univ. of New South Wales)

• Christy Keenan

• Ahn Pham

Oxidative Treatment Technologies

• Motivation– Recalcitrant polar contaminants (e.g., NDMA)– Hydrophobic contaminants (e.g., PCBs)– Passive treatment (e.g., As in groundwater)

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

Fe Nanoparticles as Reductants

• Currently used for contaminant reduction

Zhang (2003)

Fe Nanoparticles as Oxidants

• Oxygen activation during Fe corrosion

Fe0(s) Fe2+

O2 O22- H2O2 H2O

OH OH-

2H+ Fe0(s) Fe2+

Fe2+

Fe3+ + OH-

.RH R

.oxid

Oxidation of Molinate by Fe Nanoparticles

Joo et al. (2004)

N2

O2

air

Oxidation of As(III) by Fe

• As(III) oxidation and As(V) adsorption

Leupin & Hug (2005)

Oxidation of As(III) by Fe

• Selective As(III) oxidation

Hug and Leupin (2003)

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