new directions for electrokinetic remediation research - uma · krishna r. reddy, claudio cameselle...

New Directions for Electrokinetic Remediation Research

Krishna R. Reddy, PhD, PE, DGE, FASCEProfessor of Civil & Environmental Engineering

Director, Geotechnical & Geoenvironmental LaboratoryUniversity of Illinois, Chicago, USA

13th Symposium on Electrokinetic Remediation (EREM2014)Malaga, Spain, September 8, 2014

Presentation Outline

1. Status on Electrokinetic Remediation

2. Current Research Trends

3. Practical Issues/Considerations

4. Final Remarks

The Problem

Estimated Number of Contaminated Sites in the U.S. (Cleanup horizon: 2004 – 2033)

Just started to realize the problem in developing countries such as India, China,...

Remediation Technologies

Soil Remediation•Soil Vapor Extraction

•Soil Washing/Flushing

•Chemical Oxidation/Reduction

•Stabilization/Solidification

•Electrokinetic Remediation

•Thermal Desorption

•Vitrification

•Bioremediation

•Phytoremediation

Groundwater Remediation•Pump and Treat

•In-Situ Flushing

•Permeable Reactive Barriers

•Air Sparging

•Monitored Natural Attenuation

•Bioremediation

Still striving to develop efficient, rapid and cost-effective in-situ technologies?

Electrokinetic Remediation (EKR)

Fundamentals:

•Electrolysis•Electromigration•Electroosmosis•Electrophoresis•Geochemical Reactions

•Adsorption/Desorption•Precipitation/Dissolution•Oxidation/Reduction•Complexation Rxns•…

Dynamic geochemistry Spatial and temporal changes in solution chemistry and solid surface properties

Unique Advantages

� Applicable to Different Soil Conditions� Low Permeability/Heterogeneous Soils

� Unsaturated and Saturated Soils

� Applicable to Variety of Contaminants� Metals, Radionuclides, or Organic Compounds

� Mixed Contaminants

� Easy to integrate with other remediation technologies

Electrokinetic Remediation: Overview

Krishna R. Reddy, Claudio Cameselle(Editors)

ISBN: 978-0-470-38343-8Hardcover. 760 pages. September 2009.

www.wiley.com

Electrochemical Remediation Technologies for Polluted Soils, Sediments and Groundwater

Removal of Heavy Metals

• Cationic Metals

– Migrate towards the cathode

– Migration retarded by high pH and the presence of multiple contaminants

• Anionic Metals

– Migrate towards the anode

– Migration retarded by low pH and the presence of multiple contaminants

• Enhancement Strategies– Increase treatment duration?– Increase electric potential gradient/vary mode of

application? Polarity reversal?– Use cation/anion exchange membranes in the electrodes?– Circulating electrolytes?– Use enhancement (electrode conditioning) solutions

• Chelates (e.g., EDTA, DTPA)• Organic Acids (e.g., Acetic Acid, Citric Acid)

Removal of Organic Contaminants

Hydrophobic organic contaminants must be desorbed/solubilized using:•Surfactants•Cosolvents•Cyclodextrins

Removal depends upon electroosmosis (EO), but EO decreases due to: reduced electrical conductivity, reduced soil pH (<PZC), and the type of flushing solution used

Sustain/increase EO by:•pH control (>PZC throughout the soil)•Magnitude/Mode of electric potential application (e.g., pulsed- on/off cycles)

Integrated/Coupled Technologies

• Integrated (or Coupled) Technologies such as– Electrokinetic Chemical Oxidation/Reduction– Electrokinetic Bioremediation– Electrokinetic Phytoremediation– Electrokinetic Permeable Reactive Barriers– Electrokinetic Stabilization– …

• Advantages– Overcome the deficiencies of common technologies– Detoxify organics within the soil/groundwater (no effluent to

treat)– Remove/recover heavy metals (no long-term issues/value)– Achieve both of the above (ideal for mixed contaminants)– Practical?– Cost-effective?

EKR Current Status

� Electrokinetic remdiation by itself or with enhancements may be costly and impractical.

� Integrated electrokinetic remediation technologies have great potential to be effective and practical.

� Ideally suited for:� Remediation of low permeability/heterogeneous subsurface� Source zone remediation� Difficult contaminants� Mixed contaminants

� Provides greater flexibility to adapt at any time during the remediation process to changing or different contaminant conditions, without the need for major changes in the field setup

Topic=(electrokinetic remediation)

Results: 885

Source: Web of Science

Current Research Trends

(As of August 15, 2014)

EKR continues to be a very active research topic worldwide!!!


Results: 885

Source: Web of Science


EKR Publications


Results: 2957

Source: Google Scholar


EKR Publications

Basic Vs Applied Research

Practical Issues/Considerations

1. Reliability of the technology

2. Costs of application

3. Practicality of implementation

4. Application of and ability to meet risk-based remediation goals

5. Anticipated remediation time

6. Acceptability to project stakeholders

7. Necessity of special permits

8. Implications on end-use of the site

9. Sustainability considerations, including triple bottom line parameters

10.Remediation versus management paradigm for complex sites

Removal of Heavy Metals

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0.00

0.20

0.40

0.60

0.80

1.00

anode section 1 section 2 section 3 section 4 section 5 cathode

pH

mas

s fr

actio

n

Ni (II) Kaolin

INITIAL MASS

Cr (VI) Glacial Till

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90


mas

s fr

actio

n

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

pH

INITIAL MASS

Ni (II) Glacial Till

0.00

0.20

0.40

0.60

0.80

1.00


mas

s fr

actio

n

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

pH

INITIAL MASS

Cr (VI) Kaolin

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90


mas

s fr

actio

n

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

pH

INITIAL MASS

Enhanced Heavy Metal Removal

12

0

7

83

10

2320 19

12

6871

94

0

10

20

30

40

50

60

70

80

90

100

Chromium Nickel Cadmium

% R

emo

val

Overall Removal EfficiencyKaolin

WaterEDTAAcetic AcidSQEEK

Enhanced Heavy Metal Removal

Overall Removal EfficiencyGlacial Till

17

10

0

46

0 0

79

1410

82

1416

73

0 0

58

49

26

0

10

20

30

40

50

60

70

80

90

Chromium Nickel Cadmium

% R

emo

val

Water

EDTA

Acetic Acid

Citric Acid

Sulfuric Acid

SQEEK

Removal of Organic Contaminants

0

500

1000

1500

2000

2500

0 50 100 150 200 250 300Elapsed Time (days)

Cu

mu

lati

ve F

low

Vo

lum

e (m

L)

PeriodicContinuous

Kaolin; Phenanthrene=500 mg/kgAnode: 0.01M NaOH/Surfactant; VG=2 VDC/cm

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

0 0.2 0.4 0.6 0.8 1

No

rmal

ized

Co

nce

ntra

tion

C/C

o

Normalized Distance from Anode

PeriodicContinuous

Removal of Mixed Contaminants

EK-NP-1: 5% Igepal

012345678

0 0.2 0.4 0.6 0.8 1Normalized distance from Anode

Con

cent

ratio

n (C

/Co

) Nickel

Phenanthrene

(Conc. 500 mg/kg each; 2 VDC/cm-periodic)

H2O2 Conc.

0

100

200

300

400

500

600

0 0.2 0.4 0.6 0.8 1


Ph

enan

thre

ne

Co

nce

ntr

atio

n

(mg

/Kg

)

Initial0%5%10%20%30%

Integrated EK-Fenton

Kaolin Soil with Phenanthrene and Nickel (each at 500 mg/kg); VG=1 VDC/cm

H2O2 Conc.

0

500

1000

1500

2000

2500

3000

0 0.2 0.4 0.6 0.8 1


Nic

kel C

on

cen

trat

ion

(m

g/K

g)

Initial0%5%10%20%30%

Co-Existing Ni Removal

Kaolin Soil with Phen and Nickel (each at 500 mg/kg)

Field Contaminated Soils

PROPERTY Field A* Soil B** Soil D* Soil E*% gravel = 0 % gravel = 0 % gravel = 1.8 - 15.4 % gravel = 0.1

Grain size distribution % sand = 84.0 % sand = 5.2 % sand = 50.1- 65.6 % sand = 8.4% fines = 16.0 % fines = 94.8 % fines = 32.6 - 34.5 % fines = 91.5

LL = 50.0 LL = 45.0Atterberg limits Non-Plastic PL = 24.0 Non-Plastic PL = 31.7

PI = 26.0 PI = 13.7USCS classification SP-SM CH - fat clay SM CL

Water content N/A 6.36% 7.55% 78.60%Organic content 11.10% 2.63% 2.69% - 3.75% 19.20%Specific gravity 2.68 2.52 2.54 1.25Max. dry density N/A N/A 2.03 g/cm3 1.35 g/cm3

Optimum moisture content N/A N/A 10.40% 24.00%pH 7 7.56 6.9 7

Redox porential -0.05 mV -58.1 mV 186.4 mV 184.3 mVElectrical conductivity 2.68 m-s/cm 11.58 m-s/cm 1435 m-s/cm 0.37 m-s/cm

All the soil properties were determined by ASTM standards*Contaminated with both heavy metals and PAHs** Contaminated with heavy metals only

Testing Program

9 EK-B-1 2 0.2M EDTA 1.910 EK-B-2 2 0.2M KI 0.2811 EK-B-3 2 0.2M DTPA 1.512 EK-B-4 2 10% HP-β - CD 0.813 EK-B-5 2 0.2M KI -14 EK-B-6 2 0.2M EDTA -15 EK-B-7 1 0.2M KI -16 EK-B-8 1 0.2M EDTA -17 EK-D-1 2 5% Igepal CA-720 7.218 EK-D-2 2 10% HP-β - CD 7.519 EK-D-3 2 20% n-Butylamine 10.720 EK-D-4 2 3% Tween 80 2.121 EK-E-1 2 5% Igepal CA-720 1122 EK-E-2 2 10% HP-β - CD 5.323 EK-E-3 2 20% n-Butylamine 14.724 EK-E-4 2 3% Tween 80 15.9

Test Testing Voltage PoreNumber Designation Gradient Volumes

(VDC/cm)0 Deionized Water 11.21 Deionized Water 100 0.2M EDTA 61 0.2M EDTA 5.50 5% Igepal CA-720 5.61 5% Igepal CA-720 5.80 0.2M EDTA 21.90 5% Igepal CA-720 20.50 5% Igepal CA-720 21.20 0.2M EDTA 21.20 5% Igepal CA-720 6.60 0.2M EDTA 5.81 5% Igepal CA-720 5.61 0.2M EDTA 6.5

7 EK-A-6 0 10% HP-β - CD 20.88 EK-A-7 0 10% HP-β - CD 8.2

5 EK-A-4

6 EK-A-5

3 EK-A-1a

4 EK-A-3

Flushing Solution

1 EK-A-1

2 EK-A-2

Field Soil A

0

10

20

30

40

50

60

70

80

90

100

Aluminu

mAnti

mony

Arsen

icBar

iumBer

yllium

Cadmium

Calcium

Chrom

iumCob

altCop

per

Iron

Lead

Mag

nesiu

mM

anga

nese

Mer

cury

Nickel

Potas

sium

Seleniu

mSilv

erSod

iumTh

allium

Vanad

ium Zinc

% R

emo

val

EK-A-1EK-A-1aEK-A-2EK-A-3EK-A-4EK-A-5

Field Soil A

0

10

20

30

40

50

60

70

80

90

100

Acena

phth

ene

Acena

phth

ylene

Anthr

acen

e

Benz(a

)ant

hrac

ene

Benzo

(a)p

yrene

Benzo

(b)flu

oran

then

e

Benzo

(g,h

,i)per

ylene

Benzo

(k)flu

oran

then

eChr

ysen

e

Dibenz

(a,h

)ant

hrac

ene

Fluora

nthe

neFluo

rene

Inde

no(1

,2,3

-cd)p

yrene

Napht

halen

e

Phena

nthr

ene

Pyrene

% R

emov

alEK-A-1

EK-A-1a

EK-A-2

EK-A-3

EK-A-4

EK-A-5

Field Soil B

EK-B-1 Toxic Contaminant Distribution

0

500

1000

1500

2000

2500

3000

3500

Lead Mercury

Co

nta

min

ant

con

cen

trat

ion

(m

g/k

g)

S-1 (Near Anode)

S-2 (Middle)

S-3 (Near Cathode)

EK-B-2 Toxic Contaminant Distribution

0

200

400

600

800

1000

1200

Lead MercuryC

on

tam

inan

t C

on

cen

trat

ion

(m

g/k

g)

S-1 (Near Anode)

S-2 (Middle)

S-3 (Near Cathode)

• EK-B-3 and EK-B-4 were not effective in contaminant removal

0.2M EDTA, 2VDC/cm 0.2M KI, 2VDC/cm

Field Soil D

EK-D-1, % Remaining in Each Soil Section

0102030405060708090

100

Acena

phthe

ne

Acena

phth

ylene

Anthr

acen

e

Benz(

a)an

thra

cene

Benzo

(a)p

yren

e

Benzo

(b)fl

uora

nthe

ne

Benzo

(g,h,

i)per

ylene

Benzo

(k)flu

oran

then

eChr

ysen

e

Dibenz

(a,h

)anth

race

ne

Fluora

nthe

neFluo

rene

Inde

no(1

,2,3-

cd)p

yren

e

Naphth

alene

Phena

nthr

ene

Pyren

e

Per

cen

t Rem

aini

ng (%

) S-1 (Near Anode)S-2 (Middle)S-3 (Near Cathode)

EK-D-4, % Remaining in Each Soil Section

0102030405060708090

100

Acena

phth

ene

Acena

phth

ylene

Anthr

acen

e

Benz(

a)an

thra

cene

Benzo

(a)p

yren

e

Benzo

(b)fl

uora

nthe

ne

Benzo

(g,h,

i)per

ylene

Benzo

(k)flu

oran

then

eChr

ysen

e

Dibenz

(a,h

)anth

race

ne

Fluora

nthen

eFluo

rene

Inde

no(1

,2,3-

cd)p

yren

e

Naphth

alene

Phena

nthr

ene

Pyren

e

S-1 (Near Anode)S-2 (Middle)S-3 (Near Cathode)

• EK-D-2, EK-D-3 were not effective in contaminant removal

5% Igepal, 2VDC/cm 3% Tween, 2VDC/cm

Field Soil E

0

5

10

15

20

Acena

phth

ene

Acena

phth

ylene

Anthr

acen

e

Benz(

a)an

thra

cene

Benzo

(a)p

yren

e

Benzo

(b)fl

uora

nthe

ne

Benzo

(g,h,

i)per

ylene

Benzo

(k)fl

uora

nthe

neChr

ysen

e

Dibenz

(a,h

)ant

hrac

ene

Fluora

nthen

eFluo

rene

Inde

no(1

,2,3

-cd)

pyre

ne

Napht

halen

e

Phena

nthr

ene

Pyren

e

% R

emo

val EK-E-1

EK-E-2EK-E-3EK-E-4

•No heavy metals were removed

So, how reliable is this technology?

Costs of Application

• Costs depend on:– Zone of contamination (area and depth), type of

contaminants, and type of soils– Initial and target contaminant concentrations– Electrode wells & electrodes and their installation – Electrode conditioning solutions– Electricity consumption– Effluent treatment– Operation and monitoring– Site preparation and permits

• Actual costs unknown, estimated to be:– $20 to $225/yd3, but generally more than $60/yd3

– Very deep sources (>40 ft) and very small sites (<0.1 acres) usually cost more whereas larger, shallower sites cost less.

• Bottom line is that the costs have to be lowered.

Costs of Application

• Large scale EK systems should be simple to be competitive.

• Extensive electrode fluid management:

– expensive

– high operating costs

– greater chance of failure.

• Manage the cathode and anode fluids as passively as possible.

So, what is the cost of using this technology?

Practical Considerations










10.Remediation versus management paradigm for complex sites.

Electro-reclamation at Loppersum

� Year 1989

� Volume 250 m³

� Type of contamination

� As in heavy clay

� Concentration at start

� Max. 500 mg/kg

� Average 115 mg/kg

� Concentration at end

� Max. 29 mg/kg


� Energy 150 kW/ton

� Duration

� 80 days of 18 hours

� Product removed

� 38 kg As by ER

� 14 kg As by excavation

(Lageman, 2003)

Electro-reclamation at Stadskanaal

� Year 1990-1992

� Volume 2500 m³

� Type of contamination

� Cd in fine clayey sand

� Concentration at start

� Cd >2000 mg/kg


� Concentration at end

� Cd 5-40 mg/kg



� Duration

� 2 ½ years(Lageman, 2003)

Electro-reclamation at Woensdrecht

� Year 1992-1994

� Volume 3500 m³


� Duration

� 2 years

(Lageman, 2003)

0

2000

4000

6000

8000

Co

nce

ntr

atio

n (

mg

/kg

)

75

80

85

90

95

100

Dec

reas

e (%

)

Start (mg/kg) 7300 2600 860 770 730 660

End (mg/kg) 755 860 80 98 108 47

Decrease % 90 89 91 87 85 93

Cr Zn Ni Cu Pb Cd

EK: LasagnaTM Process

(Athmer, 2004)

LasagnaTM is the patented and trademarked name for the integration of DC electricity and in-situ treatment and was developed by a consortium of scientists from DuPont, General Electric and Monsanto along with the USEPA and US DOE.

Installation of Electrodes

Lasagna™ system installation was extremely successful in reducing TCE contamination at sites in the USA


• DOE Facility, Paducah, KY

• TCE stored in a lined pit and used for testing of uranium storage steel cylinders

• TCE leaked and contaminated subsoil

• Clayey soil, K=1x10-6

cm/s

• Contaminated zone:90’x70’x40’

• Max TCE conc. 1500 mg/kg

(Athmer, 2004)


• Electrodes and treatment zones installed with hollow mandrel systems

• Steel plate electrodes at 45’ spacing

• Treatment zones (1-inch thick) at 5’ spacing (iron filings)

• Powered 415-220 volts, depending on temperature increase (50 to 900C)

• EO flow at 0.5 cm/day, recycled, 1.6 pore volumes

(Athmer, 2004)


• Average TCE conc. of 0.38 mg/kg with max. conc. 4.5 mg/kg

• Only one sample had detectable levels of cis,1-2-dichloroethylene

(Athmer, 2004)

e-Barrier

(Sale et al., 2005)

Bench-scale Study

TCE as a function of position (20 V). Position 0 is the center of the electrode pack.

(Sale et al., 2005)

Composite Panel Detail

(Sale et al., 2005)

Construction

Initial topsoil removal

Excavation priorto trench box installation

Electrode panel components Lifting of nine linked e-barrier modules (panels) prior to placement in trench

(Sale et al., 2005)

Construction

Placement of eight linked e-barrier modules into the trench linking with in-place ebarrier modules

Backfilling of trench with imported soil. Note risers containing electrical connections, gas vests, washout tubing and multilevel sampling bundles

Top of risers prior to surface completion Surface completion(Sale et al., 2005)

Lessons Learned

• Sustained TCE flux reduction up to 95%

• No adverse reaction intermediates

• Cost comparable to other technologies (e.g. ZVI PRB)

• Limitations:– Deep installation– Scale formation in high TDS waters– Flux reduction may be insufficient to meet the regulatory

groundwater concentration requirement

Practicality of Implementation

• Useful for small, source zones

• Very limited full-scale applications in the USA!

– LasagnaTM process is well documented!

• Incomplete technology developers’ information on pilot or full-scale field applications

• Lack of well documented case studies (detailed design, performance data and cost)

• No guidance on designing full-scale systems

Practicality of Implementation

• Well based electrodes may not be efficient– significant reduction in electrical current passage and voltage

drop due to open area.

• Larger planar electrodes are easier to install than well based electrode– no waste soil to manage

• EK systems should be coupled with in-situ destruction techniques

– ZVI barrier walls placed in the flow path works well (LasagnaTM)

– Enhanced bio shows promise

– Electrolytic barrier

So, how practical is to implement this technology?

Pre-Risk Era (Early 80s)

• Remediation goals often set to “pristine”condition/restoration

• Proved to be cost and time prohibitive

Emergence of Risk Era

‣ National Research Council/National Academy of Sciences (NRC/NAS)

‣ RED BOOK (1983) Risk Assessment in the Federal Government: Managing the Process

• Addressed health risk assessments across all Federal Agencies

• Defined four-step risk assessment process

• Steps used in several EPA statutes but with different methods (e.g., RCRA, CERCLA, FIFRA, TSCA)

Risk Assessment & Management

Risk Characterization

• Likelihood of injury, disease, or death resulting from exposure to a potential environmental hazard

• Cancer Risk Equation

• Cancer Risk = ADD x CSF– Risk = incremental probability of an individual developing cancer from

exposure– ADD = chronic lifetime daily dose averaged over 70 years– CSF = cancer slope (or potency) factor

• Noncancer Risk Equation

• Hazard Quotient = ADD/RfD– ADD = average daily dose (or intake)– RfD = reference dose– HI > 1 – potentially of health concern

• Address uncertainty and variability

• Assumes risk additive over all chemicals in mixture

Risk-based Screening & Corrective Levels

• Calculate allowable concentrations in media based on allowable risk - inverse of USEPA approach

• Risk-based Corrective Action (RBCA) for Petroleum Release Sites

– ASTM E1739– Tiered Approach

• States - examples• Illinois: Tiered Approach to Corrective Action Objectives

(TACO)- IAC 620• California:

» Department of Toxic Substances Control (DTSC) – California Human Health Screening Levels (CHHSLs)

» San Francisco Bay Regional Water Quality Control Board (RWQCB) –Environmental Screening Levels (ESLs)

Contaminant Type

Residential Properties -Concentration (mg/kg)

Industrial/Commercial Properties -Concentration (mg/kg)

Ingestion Inhalation Soil component of ground water

ingestion

Ingestion Inhalation Soil component of ground water

ingestion

Class I Class II Class I Class II

Arsenic - 750 0.05 0.2 - 1200 0.05 0.2

Barium 5500 690000 2 2 140000 910000 2 2

Cadmium 78 1800 0.005 0.05 2000 2800 0.005 0.05

Chromium 230 270 0.1 1 6100 420 0.1 1

Lead 400 - 0.0075 0.1 800 - 0.0075 0.1

Anthracene 23000 - 12000 59000 610000 - 12000 59000

Benzo(a)pyrene 0.09 - 8 82 0.8 - 8 82

Benzo(k)fluoranthene

9 - 49 250 78 - 49 250

Fluoranthene 3100 - 4300 21000 82000 - 4300 21000

Naphthalene 1600 170 12 18 41000 270 12 18

Pyrene 2300 - 4200 21000 61000 - 4200 21000

TACO Tier 1 SRO

(Sharma and Reddy, 2004)

How are treatment target concentrations decided?











10.Remediation versus management paradigm for complex sites.

Anticipated Remediation Time

• No reliable way to estimate remediation time

– Limited modeling studies

• Depends on the site area/depth, contamination, and EK system design/operation

• Case studies

– Lageman (1989-94)• Heavy Metal Site 1: 80 days

• Heavy Metal Site 2: 2.5 years

• Heavy Metal Site 3: 2 years

– Athmer (2004)• TCE Site 1: 2 years

• TCE Site 2: 2.5 years

– Sale et al. (2005)• TCE Site: 1.5 years

How can we estimate cleanup time?

Stakeholder Acceptability

• Stakeholders

– Owner, consultant, regulators/government, community/public

• Effects on underground utilities and liabilities

Special Permits

• Injection of electrode conditioning solutions

– Toxicity data

– Fate of residual in subsurface

• Compatibility of electrodes with subsurface

• Effluent management and treatment

– Treatment

– Discharge permits (e.g., NPDES)

End-use of the Site

• What will be the end-use of the site?– Residential

– Commercial

– Agricultural

– Nature preserve

• End-use affects the remediation goals (based on human and ecological risks)

• Physical, mineralogical, chemical and biological changes in subsurface due to EK

– Extreme final pH, depletion of nutrients,…

• Will the treated soil suitable as:– Construction material/support (strength, compressibility,

hydraulic conductivity,…)

– Agricultural land (nutrients, crop growth,…)

– Habitat

Sustainability

� Presidents’ Executive Orders� 13123-Greening the Government through

Efficient Energy Management (6/1999)

� 13514-Federal Leadership in Environmental, Energy, and Economic Performance (10/2009)

� 2011 NRC Green Book� Recommends EPA to formally adopt

sustainability approach

� Framework for EPA Sustainability Decisions

� Theme – “Cleanup based on holistic approach (triple bottom line)”

Green and Sustainable Remediation

Definition“the site-specific use of products, processes, technologies, and procedures that mitigate contaminant risk to receptors while balancing community goals, economicimpacts, and netenvironmental effects”

(ITRC, ASTM)

Core Elements of Green Remediation

“Reduction, Efficiency,

and Renewables…”

“Protect Air Quality; Reduce

Greenhouse Gases…”

“Minimize, Reuse, and Recycle…”

“Conserve, Protect,

and Restore…”

“Improve Quality; Decrease Quantity of Use…”

(USEPA)

Triple Bottom Line/Sustainable Design

Sustainability/LCA-based Design

• Electrode Choice

• Electrode Conditioning Solutions Choice

• Energy Source/Consumption

• Water Consumption

• Waste/Effluent Generated

• Direct and Indirect Economic Benefits

• Community Acceptance/Benefits

Net broader impacts?

Electrodes: LCA Results

Electrode Types

Titanium Iron Graphite Carbon

Impa

cts,

mP

t

0

100

200

300

400

500

Carcinogens Resp. organics Resp. inorganics Climate change Radiation Ozone layer Ecotoxicity Acidification/ Eutrophication Land use Minerals Fossil fuels

Electrode Solutions: LCA Results

Electrode Solutions

Solvent EDTA DTPA Citric Acid Acetic Acid

Impa

cts,

mP

t

0

100

200

300

400

500

600 Carcinogens Resp. organics Resp. inorganics Climate change Radiation Ozone layer Ecotoxicity Acidification/ Eutrophication Land use Minerals Fossil fuels

Management vs Remediation Paradigm for Complex Sites

• NRC report published in 2013

Complex Sites• Fractured media• Very large plumes• Radioactive contaminants• Very deep contamination• Fine-grained units

Complex Sites

Passive Long-termManagement Option MNA, NA, permeable reactive barrier, orphysical containment

Active Long-term Management Option•Community outreach program•Contaminant monitoring plan •Institutional and engineering controls

Final Remarks

Electrokinetic remediation by itself or with enhancements may be ineffective and/or costly

Integrated electrokinetic/electrochemical remediation technologies have great potential to be effective and practical•Potential to design green and sustainable systems (use DC solar power supply, in-situ degradation, metal recovery & reuse)

Ideally suited for:•Remediation of low permeability/heterogeneous subsurface•Source zone remediation•Difficult contaminants, including the contaminant mixtures

1

2

3

Final Remarks

Provides greater flexibility to adapt at any time during the remediation process to changing or different contaminant conditions, without the need for major changes in the field setup

Many studies investigated the fundamental aspects of electrokinetic remediation, but very limited studies address the practical issues to successfully implement the technology at actual contaminated sites-Need more use-inspired basic research/applied research

4

5

Take Away Message










10. Remediation versus management paradigm for complex sites

As we do our research, let’s keep the following practical considerations in mind:

Acknowledgements

• Funding

• Graduate Students

– R. Saichek

– S. Chinthamreddy

– K. Maturi

– A. Al-Hamdan

– K. Darko-Kagya

• Related Publications

www.uic.edu/labs/geotech

Thanks!

Questions & Answers

new directions for electrokinetic remediation research - uma · krishna r. reddy, claudio cameselle...

Documents