Nano-Scale Zero-Valent IronState of the Technology

Lessons Learned from R&D, Production,and Global Field Implementations

Presentation Outline

1. Timeline of Significant IP Developments2. Production3. Key Technical Issues

nZVI ReactivitynZVI ReactivitynZVI Deliverability nZVI Treatment LongevitynZVI Treatment LongevityToxicity and Risk

4 Experience Valcartier Garrison Canada4. Experience – Valcartier Garrison, Canada

July 20, 2009 2

Timeline of Significant IP Developments

Waterloo patent (1993)Applicable to any iron body (iron only) placed in the ground by any means (PRB reactive zone etc ) EnviroMetal Incby any means (PRB, reactive zone, etc.). EnviroMetal Inc (Adventus) exclusive license.

NASA (2003)EZVI = Emulsified Zero Valent Iron Colloidal iron in oilEZVI = Emulsified Zero Valent Iron. Colloidal iron in oil emulsion (DNAPL application)

Lehigh - Zhang (2005)P d ti d f ZVI ( l BNP) f d tProduction and use of nZVI (also BNP) for groundwater remediation

Golder produces and implements nZVI under non-exclusive license from Lehigh University

July 20, 2009 3

Production

Mechanically Ground / Ball-Milling

Stock ZVI

2-5 μmTop-down

Physical size reductionLehigh University (2005)

B tt

(2005)

Bottom-up

Atoms orChemically Precipitated

Cl i l th d i Atoms or molecules

Classical method since 1996Borohydride reduction

July 20, 2009 4

nZVI Reactivity – Surface Chemistry

Fe2+ Half ReactionsFe0 Fe2+ + 2e-

e- RCl + H+

Fe0 Fe2+ _+ 2e-

C2HCl3 + 2e- + H+ C2HCl2 + Cl-

O ll R ti (TCE t Eth )Overall Reaction (TCE to Ethene)3Fe0 + C2HCl3 + 3H+ 3Fe2+ + C2H4+ 3Cl-

Fe Surface

RH + Cl-

Surface

July 20, 2009 5

nZVI Reactivity – Chemistry Background

Fe0 core that shrinks over timeIron oxide coating forms immediately with contact of H2O or air

Iron oxides will interact with aquifer materialsqWill not travel indefinitely

Agglomeration ultimately forms Fe-oxide flocs with some continued reactivityPalladium added as catalyst

0.05% wt/wtEnhances reactivityEnhances treatment longevity

July 20, 2009 6

Image from Zhang (2005)

nZVI Reactivity – Reaction Pathways

~ 80% to 90%

~ 10% to 20%

Roberts, A. L., et. al, 1996 Reductive Elimination of Chlorinated Ethylene by ZVI Metals. Environmental Science and Tech.

July 20, 2009 7

nZVI Reactivity – Size Issues

Definition - “nano” is <100 nm and novel properties versus bulk-scale

Nature Paper to come soon (accepted) for citation

Truly “nano” iron may not occur until below 10 nm and potentially far below

July 20, 2009 8

Graph taken from Tratnyek and Johnson (2006)

nZVI Deliverability - Agglomeration Issues

Surface charge promotes agglomerationFe0 is magnetic, promotes agglomerationg , p ggMore dense slurry, more particle interactionNeed to modify the nZVI surface to maintainNeed to modify the nZVI surface to maintain suspension

Fe(0) Fe(0)

July 20, 2009 9

nZVI Deliverability - Surface Modification

July 20, 2009 10

nZVI Treatment Longevity

Paradigm shift from abiotic treatment of CAHs to reagent for enhanced bioremediation approachObserved transition of abiotic CAH degradation to enhancedObserved transition of abiotic CAH degradation to enhanced bioremediationTransition driven by altered redox condition coupled with addition of complex source of soluble and sparring soluble carboncomplex source of soluble and sparring soluble carbonContinued degradation of CAHs observed for over two (2) years and achieved a groundwater concentration target of 5 ppb for TCE without build-up of intermediate degradation productsbuild up of intermediate degradation productsCombined remedy of nZVI injection and long-term enhanced bioremediation may be a strong candidate technology for specific CAH impacted sitesimpacted sites

July 20, 2009 11

Toxicity and Risk

48 hour LC50 ~ 55 ppmSame as bulk ironClassified as slightly toxicClassified as slightly toxicNo different from PRBs

Fish study shows no mortality

Taken from: Oberdorster et al., Rapid Environmental Impact Screening for Engineered Nanomaterials: A Case Study Using Microarray Technology June 2006

July 20, 2009 12

Experience – Valcartier Garrison, Canada

Plume Characteristics

2.5 miles long0.5 miles wide130 ft deepTCEMultiple pSource Areas

July 20, 200913

OOPO 06 11PO-06-12 PO PO 06 7

Injection LayoutPO-06-8PO-06-10PO-06-11PO-06-12

PO-06-15

PO-06-9

PFD-2

PFD-3

PFD-4 PFD-5PFD-6

PFD-7

PFD-8

PFD-9PFD-10

PFD-12

PFD-13

PFD-15PFD-16

PFD-17

PFD-18

PFD-19

PFD-20PO-06-14

PO 06 13

PFD-21PFD-23

CPT-10

PO-06-7

5PI-06-5PI-06-6

PO 06 5

PFD-1

PFD 8

PFD-11

PFD-14

PI-06-7 PI-06-4 PI-06-3

PO-06-13

PO-06-16CPT-5

CPT-4

CPT-8CPT-9

CPT-7PI-06-8

PFD-22PFD-24

CPT-11

PI-06-2 PI-06-1

Treatment

5 m

40 mPO-06-3PO-06-4PO-06-5PO-06-6

CPT-6 PO-06-2 PO-06-1CPT-1 zone

Groundwater flow

4,500 kg of Golder nZVI0.1% PdSlurry density of 10 g/l to 40 g/ly y g g80,000 L soy protein dispersant

July 20, 2009 14

Geochemistry

ORP (200 V)

O2 (9.5 mg/l)

ORP ( 4 0 V)

O2 (0.7 mg/l) O2 (2.0 mg/l)

Mean Geochemical Values Across the Treatment Area

ORP (-100 mV)ORP (200 mV)

TOC(1 5 /l)

pH (6.3)

BOD (<4 mg/l)

ORP (-450 mV)

TOC(250 /l)

pH (6.1)

TOC(25 /l)

pH (7.0)

BOD (15 mg/l)(1,5 mg/l)

Before NZVI

(250 mg/l) (25 mg/l)

1 month 12 monthBefore NZVI injection

1 monthafter

12 monthafter

Values measured in the treatment areaValues measured in the treatment area

Values measured at the injection wells

July 20, 2009 15

TCE Progress Monitoring

300

350Injection #1 Injection #2 Injection #3

200

250

E (u

g/L)

150

Con

cent

ratio

n TC

E

50

100

002-juil-06 21-août-06 10-oct-06 29-nov-06 18-janv-07 09-mars-07 28-avr-07 17-juin-07 06-août-07 25-sept-07 14-nov-07 03-janv-08

Date (JJ-MM-AA)

PI-06-1 PI-06-2 PI-06-3 PI-06-4 PI-06-5 PI-06-6 PI-06-7 PI-06-8

Performance criteria

July 20, 2009 16

PI 06 1 PI 06 2 PI 06 3 PI 06 4 PI 06 5 PI 06 6 PI 06 7 PI 06 8

Cis-1,2-DCE Progress Monitoring

180

200Injection #1 Injection #2 Injection #3

120

140

160

E (u

g/L)

80

100

Con

cent

ratio

n D

CE

20

40

60

Performance criteria

002-juil-06 21-août-06 10-oct-06 29-nov-06 18-janv-07 09-mars-07 28-avr-07 17-juin-07 06-août-07 25-sept-07 14-nov-07 03-janv-08

Date (JJ-MM-AA)

PI-06-1 PI-06-2 PI-06-3 PI-06-4 PI-06-5 PI-06-6 PI-06-7 PI-06-8

July 20, 2009 17

Treatment performance – Plan view

Treatment zone

8 months following last injection

Treatment zone

0 -15 ppb15 - 30 ppb30 - 50 ppb

Groundwater flowdirection Observation wells

pp50 - 100 ppb

100 + ppbInjection wells

InterpretationZ f hi hZone of high reducing conditions

Zone of middly reducing conditions

Zone whereHydrogenolysisis supported

Zone whereBeta-eliminationis supported

Delivery

5 -50 ppb0 -5 ppb

> 150 ppb50 - 150 ppb5 50 ppb

July 20, 2009 20

Recirculation and Hydrogen injection

H2

Medium sand

Coarse sand

Silty claySilty clayCoarse sand

Rock 30 gpm

Performance Goal Attainment (TCE)

1000

Recirculation + H2

100

on e

n TC

E (u

g/l)

10

Con

cent

ratio

117-07-07 27-07-07 06-08-07 16-08-07 26-08-07 05-09-07 15-09-07 25-09-07 05-10-07 15-10-07 25-10-07 04-11-07 14-11-07 24-11-07 04-12-07 14-12-07 24-12-07

Date (AAAA-MM-JJ)

PFD-2 (aval) PFD-5 (aval) PFD-6 (aval)PFD-3 (aval-centre) PFD-23 (aval-centre) Critère de performanceDépart du système de recirculation SUD

July 20, 2009 22

Performance Goal Attainment (cis-1,2-DCE)1000

Recirculation + H2

100

n en

DC

E (u

g/l)

10

Con

cent

ratio

n

117-07-07 27-07-07 06-08-07 16-08-07 26-08-07 05-09-07 15-09-07 25-09-07 05-10-07 15-10-07 25-10-07 04-11-07 14-11-07 24-11-07 04-12-07 14-12-07 24-12-07

Date (AAAA-MM-JJ)

PFD-2 (aval) PFD-5 (aval) PFD-6 (aval)

PFD-3 (aval-centre) PFD-23 (aval-centre) Critère de performance MDN

Départ système recirculation SUD

July 20, 2009 23

Summary

nZVI is an effective remediation approachTransition from abiotic CAH degradation to enhanced bioremediation occurs typically within several months (as TOC drops to ~20 mg/L)Long term treatment can be achieved ( 2 years)Long-term treatment can be achieved (~ 2 years) and can be continued using more traditional enhanced bioremediation approachesppTechnology is not a panacea… must be carefully evaluated!Delivery issues can be overcome with good CSMand advanced injection techniques

July 20, 2009 24

Questions?

jpdavit@golder.com

July 20, 2009 25