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Environmental Nanotechnologies

KOREA-U.S. NanoForum

October 14-15, 2003, Seoul

Wei-xian Zhang, Associate ProfessorEnvironmental EngineeringAdvanced Materials & Nanotechnology Lehigh University, Bethlehem, PA 18015

Environ. Sci. Technol.Feature Article March 1, 2003

2003, 37 (5), 73A - 112A

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Iron Nanoparticles for Treatment of Toxic Wastes

J. of Nanoparticle Research5:323-332,2003

Acknowledgments

U.S. EPANSF PITA (PA)

Dr. C.B. WangDr. H.(Sam) LienDr. J. CaoDr. Daniel ElliottXiao-qin LiY.P. SunSteve SpearYu XueSteph KravitzPatrick ClasenTim Marks

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In the 21st century we are faced with major environmental challenges …

New approaches are required to maintain and improve soil, water, and air quality

Pesticide and Fertilizer Runoff

Oil and Chemical Spills

Abandoned Industrial and Mining Sites

Emissions of Airborne Gaseous and Particulate

Matter

Improve environmental technologies (treatment, remediation, sensing, etc.)

Improve manufacturing processes (efficiency, waste reduction, etc.)

Dematerialization

Improve environmental technologies (treatment, remediation, sensing, etc.)

Improve manufacturing processes (efficiency, waste reduction, etc.)

Dematerialization

SensorsSensors

Treatment/Treatment/RemediationRemediation

Pollution PreventionPollution PreventionPollution Prevention

Enter Nanotechnology …

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Nanoscale Technologies for Pollution Prevention

Make a manufacturing process environmentally benign.

Be an environmentally benign material.

Be a manufactured product that replaces a toxic substance or minimizes use of raw materials.

IBM, Zurich

Biological pathogens, heavy metals, organics, etc.

Nanoscale Technologies forSensing and Detection

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Treatment/Remediation

Iron Nanoparticles for Treatment of Toxic Wastes

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Why Fe?A powerful reductantEffective for transformation of many contaminantsWidely used in environ. proc.Accepted by regulatory agenciesNontoxicCheap

Why Nanoparticles?

• Small size for easy subsurface injection

• Extremely high reaction rate

• Low temperature reaction

• Added Catalytic functions

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~100 nm

Noble Metal(Pd, Pt, Ag, Ni, etc)

Base Metal

(Fe, Zn, Al, etc)

Noble Metals: - forms galvanic cells - catalyze hydrogenation

Base metal - Electron donor

C2Cl4 C2H6 + Cl-

Fe2+, Zn2+

e-

Nanoscale Bimetallic Particles

+

PrecursorsFe2+, Fe3+ Fe0

Reduction ClusterFormation

Stabilization

CMCD(Sugar)

Methods of Synthesis

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0

20

40

60

80

100

120

140

25 50 75 100 125 150 175 200 225 300 More

Diameter (nm)Fr

eque

ncy

Size (50-60 nm)

Iron particles (3-5 nm)

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Surface Area

142Lehigh (2-5 nm)

25-35Lehigh (60 nm)

~1.0Aldrich, ~10 µm

0.00121 mm(existing method)

SSA (m2/g)Fe

COSTS

Iron Filing (~mm)$0.5/kg5 m2/kg< 10 m2/dollar

Nano Iron (50 nm)$20-50/kg25,000 m2/kg> 1,000 m2/dollar

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Environmental Chemistry

Organic:

Chlorinated MethanesChlorinated EthenesChlorinated EthanesChlorinated BenzenesPCBsLindane (HCHs)

Inorganic:

Cr(VI)Pb(II)Ni(II)Cu(II)PerchlorateAs

~60 compounds tested at Lehigh

0

100

200

300

400

500

TC

E (킽

/L)

0 10 20 30 40 50

Time (hours)

0.91 g/L Fe/Pd

TCE Reduction (C2HCl3) - # 1 Contaminant in Groundwater (Samples from a site in NJ)

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)Lindane (HCH) - A Pesticide(Sample from Jacksonville, FL)(5 g/L Fe)

Aquifer Materials

β−CD-Fe nanoparticles

Transport In Porous Media(Little has been reported)

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Conceptual Geologic/Hydrogeologic Model

Conceptual Model

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Test Set-up

The Nano Fe Slurry

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Field Test (Nano Fe 10 kg)

Total volume injected = 1,600 gallons (6,056 L)Nano Fe concentration = 1.9 g/lAverage injection rate = 0.6 gpm

Injection Well B-4Monitoring Wells

B-3: 20 feet north of B-4B-2: 40 feet northeast of B-4GW-4: 63 feet north-northeast of B-4

Monitoring

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Injection Well

20 Feet Down Gradient

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Summary

Reactive Fe nanoparticles for direct injection into aquifers

Enhanced reactivity (10-1,000X)

Faster cleanup time & lower costs

12 ProjectsEnvirongenGolderGeosyntecURSTetra TechAcadis

American StdBASFBoeingFMCGlaxoSmithKlineGTEHoneywellIBMUS Navy

10-20 tons of nanoparticles in 2004 (est.)

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Nanotechnology also has the potential for harm to human health and the environment …

Keep in mind that …

Thanks