1. Destruction of Pollutants by Active Oxygen
Presentation to Mark Durcan, Micron
January 8, 2003
Frank Cheng
Department of Chemistry
University of Idaho
Moscow, Idaho
November 16, 2018
Presentation to Mark Durcan, Micron

2. Presentation to Mark Durcan, Micron
Priority Pollutants
PCB
DDT
TCE
PCP
Perc
November 16, 2018
Presentation to Mark Durcan, Micron

3. Presentation to Mark Durcan, Micron
Military Focus
Explosives/Propellants
Nerve Agents
Nitrated Organics
Organophosphorous Cpds.
TNT VX
November 16, 2018
Presentation to Mark Durcan, Micron

4. Present Methods of Destruction
- Incineration > C
- CxHyClz + O2 = CO2 + H2O + HCl (unbalanced)
Problems:
- Costs (incineration and transport)
- PCDFs PCDs
- NIMBY
- Nerve agents, Gulf War Syndrome?
November 16, 2018
Presentation to Mark Durcan, Micron

5. Ideal Characteristics for Organic Pollutant Destruction
Inexpensive
Abundant reagents
Mild Reaction Conditions, Room Temperature
and Atmospheric Pressure
Simple Reactor Design
Field Portable, on site or in situ destruction
Robust with respect to the presence of water & air
-Acceptable to NIMBY
November 16, 2018
Presentation to Mark Durcan, Micron

6. Presentation to Mark Durcan, Micron
Active Oxygen
-Oxidations by O2 from air
-CxHyClz + O2 = CO2 + H2O + HCl (unbalanced) G<0
-Room temperature oxidations by air are kinetically slow
-enzymatic or enzyme-mimics
-Partially reduced O2 (active oxygen)
November 16, 2018
Presentation to Mark Durcan, Micron

7. Partially Reduced Oxygen
E0reduction
O2 + e- = O2.-
-0.45 volts
O2 + 2H+ + 2e- = H2O2
+0.30 volts
O2 + 4H+ + 4e- = H2O
+1.23 volts
November 16, 2018
Presentation to Mark Durcan, Micron

8. Presentation to Mark Durcan, Micron
Fenton Reaction
-Reduction of HO-OH
H2O2 + FeII = FeIII + HO- + HO.
HO. + e- = HO- Eo = 1.8 volts
-HO. reacts with organics with diffusion limited kinetics
November 16, 2018
Presentation to Mark Durcan, Micron

9. Presentation to Mark Durcan, Micron
Active Oxygen
O2 reducing agents
-Zero-valent iron, Fe(0)
Inexpensive
Spent agent, Fe2+/Fe3+ environmentally benign.
Chelated forms, capable oxidizing agents
Fe(0) + O2 + 2H+ => Fe2+ + H2O2
November 16, 2018
Presentation to Mark Durcan, Micron

10. Presentation to Mark Durcan, Micron
Active Oxygen
-Fe2+ chelation agent - EDTA
FeIIETDA + HOOH => FeIIIEDTA + HO- + HO.
Inexpensive
Efficient Binding Agent for Fe2+/3+
FeIIEDTA highly effective Fenton Reaction reagent
November 16, 2018
Presentation to Mark Durcan, Micron

11. Proposed Overall Scheme
Fe(0) + O2(aq) + 2H+(aq)  Fe2+(aq) + HOOH(aq)
Fe2+(aq) + EDTA  FeIIEDTA
FeIIEDTA + HOOH  FeIIIEDTA + HO- + HO·
Regeneration:
2FeIIIEDTA + Fe(0)  Fe2+(aq) + 2FeIIEDTA
November 16, 2018
Presentation to Mark Durcan, Micron

12. Pollutant Destruction
H2O2
O2 + 2H+ +
EDTA
Iron
particles
0.1-1 mm
Fe2+
FeIIEDTA
FeIIIEDTA + HO- + HO.
Aqueous
pollutant
CO2 + H2O
November 16, 2018
Presentation to Mark Durcan, Micron

13. Presentation to Mark Durcan, Micron
Aero-Fenton Reaction
0.5 g of mesh Fe(0)
10 mL of solution
0.32 mM EDTA
140 ppm 4-chlorophenol
4 hour reaction time
GC and LC-MS
November 16, 2018
Presentation to Mark Durcan, Micron

14. Destruction of other pollutants
100% removal (GC-FID)
VX surrogate - malathion
November 16, 2018
Presentation to Mark Durcan, Micron

15. Presentation to Mark Durcan, Micron
Technical Summary
Ability to degrade organic pollutants
Under room temperature, atmospheric pressure conditions
Inexpensive Reagents – Iron particles, water, air & EDTA
Unspecialized reactors
Process is easily transportable, iron particles & EDTA
Strong possibility of scale-up
November 16, 2018
Presentation to Mark Durcan, Micron

16. Presentation to Mark Durcan, Micron
Scientific Summary
First example of abiotic RTP activation of O2 able to oxidize
destructively organics
Control experiments indicate process is dependent on Fe(0), EDTA,
air, and water
November 16, 2018
Presentation to Mark Durcan, Micron

17. Future Investigations
Mechanisms – Understanding the process
Kinetics – Speeding up the process
Survey of Pollutants – oxidizable and nonoxidizable functional groups
Application & Scale-up
November 16, 2018
Presentation to Mark Durcan, Micron