Interlaboratory Validation of Leaching Methods in the ...€¦ · Interlaboratory Validation of Leaching Methods in the Leaching Environmental Assessment Framework (LEAF) for Acceptance

Interlaboratory Validation of Leaching Methods in the Leaching Environmental Assessment Framework (LEAF) for Acceptance by U.S. EPA

Andrew GARRABRANTS1, David KOSSON1, Rossane DELAPP1, Hans VAN DER SLOOT2, Leonard STEFANSKI3, Susan THORNELOE4,

Gregory HELMS5, Mark BALDWIN5, and Peter KARIHER6

1 Civil and Environmental Engineering, Vanderbilt University, Nashville, TN, USA 2 Hans van der Sloot Consultancy, 1721 BV Langedijk, NL 3 Department of Statistics, North Carolina State University Raleigh, NC, USA 4 Office of Research and Development, U.S. EPA, Durham, NC, USA 5 Office of Resource Conservation and Recovery, U.S. EPA, Washington, DC, USA 6 ARCADIS-US, Inc., Durham, NC, USA

Motivation • Materials Testing in the U.S.

• LEAF Methods

• Comparable International Methods

Interlaboratory Validation Program

Comparison to EU Leaching Tests

Conclusions

Presentation Outline

30 May - 1 June 2012 WASCON, Gothenburg, Sweden 2

1960s-1990s

Protection from Hazardous Wastes; Waste Minimization/Conservation • Classification of “Hazardous” Waste (RCRA Subtitle C/D landfills)

• Disposal Criteria for Treated Wastes (Universal Treatment Standards)

• Best Demonstrated Available Treatment (BDAT)

1990s – present

Integrated Materials Management; Environmental Performance Balanced

with Material Costs and Long-term Liability • Global Economic Policy (Resource Costs, International Trade)

• Changing “Waste” Definition (Dutch Building Materials Decree; U.S. solid waste)

• Applications for Waste Delisting and Alternative Measures of Treatment Effectiveness

• Reuse of Waste Materials (Mine Reclamation, Alternative Construction Materials)

• Revision of Coal Combustion Residue Regulations

U.S. Materials Testing (Historically)


Leaching Methods Development

Characterization Leaching Tests • Release Parameters – pH, liquid-solid ratio, time

• Material Form – granular vs. monolithic

• Applied Release Conditions – improved accuracy, reliable decisions

International Collaboration • Coordination with Parallel EU Methods Development

Situations where TCLP is Not Required or Best-Suited • Material Assessment for Beneficial Use

• Evaluation of Treatment Effectiveness (Equivalent Treatment)

• Estimating Potential Release from High-volume Materials

• Corrective Actions (Remediation Decisions)

• Hazardous Waste Delisting

30 May - 1 June 2012 4 WASCON, Gothenburg, Sweden

Leaching Environmental Assessment Framework

5 30 May - 1 June 2012 WASCON, Gothenburg, Sweden

LEAF is a collection of … • Four leaching methods

• Data management tools

• Leaching assessment approaches

LeachXS LiteTM for data management and report support

LEAF facilitates integration of leaching methods • Identify characteristic leaching behaviors in a wide range of materials

• Provide a material-specific “source term”

More information on LEAF and LeachXS Lite is available at

http://www.vanderbilt.edu/leaching

http://www.vanderbilt.edu/leaching

LEAF Leaching Methods

Method 1313 Liquid-Solid Partitioning as a Function of Eluate pH using a

Parallel Batch Procedure

Method 1314 Liquid-Solid Partitioning as a Function of Liquid-Solid Ratio

(L/S) using an Up-flow Percolation Column Procedure

Method 1315 Mass Transfer Rates in Monolithic and Compacted Granular

Materials using a Semi-dynamic Tank Leaching Procedure

Method 1316 Liquid-Solid Partitioning as a Function of Liquid-Solid Ratio

using a Parallel Batch Procedure

Note: Incorporation into SW-846 is ongoing; method numbers are subject to change.

6 30 May - 1 June 2012 6 WASCON, Gothenburg, Sweden

LEAF and EU Methods

Many of These Methods are not yet Standardized Pending Validation


Parameter LEAF Method EU Method EU Applications

pH-dependence Method 1313 CEN/TS 14429

CEN/TS 14997

ISO/TS 14997

waste, mining waste, construction products

waste, mining waste, construction products

soil, sediments, compost, sludge

Percolation Method 1314 CEN/TS 14405

CEN/TC351/TS-3

ISO/TS 21268-3

waste, mining waste

construction products

soil, sediments, compost, sludge

Mass Transport Method 1315 CEN/TS 15683

CEN/TC351/TS-2

NEN 7347 (Dutch)

NEN7348 (Dutch)

monolithic waste

monolithic construction products

monolithic waste

granular waste and construction products,

L/S dependence Method 1316 EN12457-2 waste

Validation of LEAF Test Methods


LEAF Test Methods Validation

Interlaboratory Validation Program • EPA “Guidance for Methods Development and Methods Validation for the

RCRA Program”

• ASTM “E691 Standard Practice for Conducting an Interlaboratory Study to

Determine the Precision of a Test Method”

• ISO 5725 “Accuracy (Trueness and Precision) of Measurement Methods

and Results”

Participating Laboratories (minimum of 6)

Study Materials (minimum of 3)

Method Repeatability and Reproducibility


Participating Laboratories

U.S. Government Laboratories

Oak Ridge National Lab

Pacific Northwest National Lab

Savannah River National Lab

Academic Laboratories

Ohio State University

University of Wisconsin (Madison)

Missouri Univ. of Science & Tech.

Vanderbilt University

U.S. Commercial Laboratories

ARCADIS-US, Inc.

Test America, Inc.

URS Corporation, Inc.

International Laboratories

ECN (The Netherlands)

DHI (Denmark)


Number of labs varied with test method, availability and support

• Method 1313/1316 – targeted 10 laboratories

• Method 1315 – targeted 10 laboratories

• Method 1314 – targeted 7 laboratories

Study Materials

Coal Combustion Fly Ash

• Collected for EPA study

• Selected for validation of …

Method 1313

Method 1316

Solidified Waste Analog

• Created at Vanderbilt University

• Blast Furnace Slag, Class C Fly

Ash, Type I/II Cement, Metal Salts


Method 1313

Method 1316

Method 1315

Contaminated Field Soil

• Copper smelter site

• Selected for validation of…

Method 1313

Method 1316

Method 1315

Method 1314

Brass Foundry Sand


Method 1315

Method 1314


Data Processing

Log10-Transform of Test Output • Method 1313 – Eluate Concentration

• Method 1314 – Eluate Concentration,

Cumulative Mass Release

• Method 1315 – Interval Mass Flux,

Cumulative Mass Release

• Method 1316 – Eluate Concentration

Linear Interpolation and Extrapolation • Collected Data Shows Variability

• Brings Data to Specified pH, L/S or Time

• Consistency in Comparisons

Implications for Compliance Standards


ML

MDL

0.01

0.1

1

10

0 2 4 6 8 10 12 14

Se

len

ium

(m

g/L)

pH

ML

MDL

0.01

0.1

1

10

0 2 4 6 8 10 12 14

Se

len

ium

(m

g/L)

target pH

Statistical Analysis

Data Consistency and Spread • Method Blank Analysis – to identify potential sources of contamination

• 95% Prediction and Robust Confidence Limits

Method Precision • Repeatability Relative Standard Deviation (RSDr)

“Within-Lab” Variance

• Reproducibility Relative Standard Deviation (RSDR)

“Overall” Variance

Reproducibility Limit Interval (RL) • Based on reproducibility limit (R)

• Interval within which reproducibility data

is considered to be the same with 95% confidence


%100

y

sRSD r

r

%100

y

sRSD R

R

RsR 8.2

)log()log( RyRL

Method 1313 Validation Examples


1

10

100

1000

0 2 4 6 8 10 12 14

As

Re

pro

du

cib

ilit

y (

%)

Target pH

CFS RSD-R

EaFA RSD-R

SWA RSD-R

ICP-OES RSDML

MDL0.01

0.1

1

10

100

0 2 4 6 8 10 12 14

Ars

en

ic (

mg

/L)

Target pH

M1313 EaFA MeanOverall SDBetween Lab SDWithin Lab SD

Coal Combustion Fly Ash Reproducibility

Study Materials • CFS Contaminated Field Soil • EaFA Coal Combustion Fly Ash • SWA Solidified Waste Analog

Evaluation Basis

Percolation Column Mass Transfer


1

10

100

0.1 1 10

Bo

ron

Re

lea

se

RS

DR

(%)

L/S (L/kg)

M1314 CFS RSD-R

M1314 JaFS RSD-R

ICP-OES RSD

Release at End of Test(L/S = 10 mL/g-dry )

Release through 2nd Fraction(L/S = 0.5 mL/g-dry )

1

10

100

0.1 1 10

Alu

min

um

RS

DR

(%)

L/S (L/kg)

M1314 CFS RSD-R

M1314 JaFS RSD-R

ICP-OES RSD

Concentration in 9th Fraction (L/S10)

Concentration in 2nd Fraction (L/S0.5)

1

10

100

0.01 0.1 1 10 100

Alu

min

um

Re

lea

se

RS

DR

(%)

Time (days)

M1315 CFS RSD-R

M1315 SWA RSD-R

ICP-OES RSD Release at End of Test(63-day cumulative time)

Release after 4th Interval(7-day cumulative time)

1

10

100

1000

0.01 0.1 1 10 100

Ba

riu

m F

lux

RS

DR

(%)

Time (days)

M1315 CFS RSD-R

M1315 SWA RSD-R

ICP-OES RSDMean Flux 2nd - 9th Intervals

(excludes washoff)

Flux in 4th Interval(7-day cumulative time)

Mean Flux 2nd - 4th Intervals(excludes washoff)

LEAF Method Precision


Method Test Output RSDr

(%)

RSDR

(%)

Method 1313 Eluate Concentration (average over pH range) 10 26

Method 1314 Eluate Concentration (9th fraction at L/S=10)

Mass Release (cumulative to L/S=0.5)

Mass Release (cumulative to L/S=10)

13

7

5

28

18

14

Method 1315 Interval Flux (average excluding wash-off)

Mass Release (cumulative to 7-days)

Mass Release (cumulative to 63-days)

11

9

6

28

19

23

Method 1316 Eluate Concentration (average over L/S range) 7 17

Precision Comparison (pH-dependence Tests)


0

20

40

60

80

100

EaFA SWA CFS EN12457-2 TCLPR

SD

R(%

)

Max CFSBa @ pH 13

RSDR = 300%

Max SWASb @ pH 2

RSDR = 500%

Max RSDR = 124%

Max RSDR = 118%

0

20

40

60

80

100

EaFA SWA CFS EN12457-2

RS

Dr(%

)

Max SWASb @ pH 2

RSDr = 130%

Max CFSBa @ pH 13

RSDr = 114%

Reproducibility Repeatability

Method Precision • Method 1314 Eluate Concentration (2 pH 13) • EN12457 Eluate Concentration (natural pH) • TCLP Eluate Concentration (acetic acid buffer)

Precision Comparison (Percolation Tests)


0

20

40

60

80

100

CFS JaFS DIN19528

RS

Dr(%

)

0

20

40

60

80

100

CFS JaFS DIN19528 TCLPR

SD

R(%

)

Max RSDR = 139%

Max RSDR = 118%


Method Precision • Method 1314 Cumulative Release at L/S = 10 L/kg • DIN 19528 Cumulative Release at L/S = 4.0 L/kg • TCLP Eluate Concentration (L/S = 20 L/kg)

Precision Comparison (Mass Transfer Tests)


0

20

40

60

80

100

SWA CFS NEN 7345

RS

Dr(%

)

0

20

40

60

80

100

SWA CFS NEN 7345 TCLPR

SD

R(%

)

MaxRSDR = 118%

Method Precision • Method 1315 Cumulative Release after 63 days • NEN 7345 Cumulative Release after 16 days • TCLP Eluate Concentration


Reproducibility

Precision Comparison (L/S-dependence Tests)


0

20

40

60

80

100

EaFA SWA CFS EN12457-2

RS

Dr(%

)

0

20

40

60

80

100

EaFA SWA CFS EN12457-2 TCLP

RS

DR

(%)

Max SWABa @ L/S 0.2RSDR = 175%

Max RSDR = 124%

Max RSDR = 118%

Method Precision • Method 1316 Eluate Concentration (0.5 L/S 10 L/kg) • EN12457-2 Eluate Concentration (L/S = 10 L/kg) • TCLP Eluate Concentration (L/S = 20 L/kg)

Repeatability

Comparison of LEAF and EU Test Results


pH-dependence Tests


L11-CEN/TS14429-A L11-CEN/TS14429-B L11-CEN/TS14429-C L11-CEN/TS14997-A L12-CEN/TS14997-A L12-CEN/TS14997-B L12-CEN/TS14997-C M1313 Mean M1313 95% RL

ML

MDL0.001

0.01

0.1

1

10

0 2 4 6 8 10 12 14

Mo

lyb

de

nu

m (

mg

/L)

pH


ML

MDL0.001

0.01

0.1

1

10

0 2 4 6 8 10 12 14

Mo

lyb

de

nu

m (

mg

/L)

pH

Coal Combustion Fly AshML

MDL0.001

0.01

0.1

1

10

0 2 4 6 8 10 12 14

Mo

lyb

de

nu

m (

mg

/L)

pH


ML

MDL

0.0001

0.001

0.01

0.1

1

10

100

0 2 4 6 8 10 12 14

Ch

ro

miu

m (

mg

/L)

pH

Coal Combustion Fly Ash

ML

MDL

0.0001

0.001

0.01

0.1

1

10

100

0 2 4 6 8 10 12 14

Ch

ro

miu

m (

mg

/L)

pH


Percolation (Column) Tests


L11-CEN/TS14405-A L11-CEN/TS14405-B L11-CEN/TS14405-C M1313 Mean M1313 95% RL

0.0001

0.001

0.01

0.1

1

10

100

1000

0.1 1 10 100

Bo

ro

n R

ele

ase

(m

g/k

g)

L/S (L/kg)

MDL

ML

0.0001

0.001

0.01

0.1

1

10

100

1000

0.1 1 10 100

Ca

lciu

m R

ele

ase

(m

g/k

g)

L/S (L/kg)

MDL

ML

0.0001

0.001

0.01

0.1

1

0.1 1 10 100

Mo

lyb

de

nu

m R

ele

ase

(m

g/k

g)

L/S (L/kg)

MDL

ML

0.0001

0.001

0.01

0.1

1

10

100

0.1 1 10 100

Zin

c R

ele

ase

(m

g/k

g)

L/S (L/kg)

MDL

ML

0.0001

0.001

0.01

0.1

1

10

100

0.1 1 10 100

Co

pp

er R

ele

ase

(m

g/k

g)

L/S (L/kg)

MDL

ML


Mass Transfer Tests


L11-CEN/TS15863-A L11-CEN/TS15863-B L11-CEN/TS15863-C L11-NEN 7375-A L11-NEN 7375-B L11-NEN 7375-C M1313 Mean M1313 95% RL 0.01

0.1

1

10

100

1000

0.01 0.1 1 10 100

Ba

riu

m R

ele

ase

(m

g/m

2)

Time (days)

MDL

ML

0.1

1

10

100

1000

10000

100000

0.01 0.1 1 10 100C

alc

ium

Re

lea

se

(m

g/m

2)

Time (days)

MDL

ML

0.01

0.1

1

10

100

0.01 0.1 1 10 100

Bo

ro

n R

ele

ase

(m

g/m

2)

Time (days)

MDL

ML

0.1

1

10

0.01 0.1 1 10 100

Iro

n R

ele

ase

(m

g/m

2)

Time (days)

MDL

ML

0.1

1

10

100

1000

0.01 0.1 1 10 100

An

tim

on

y R

ele

ase

(m

g/m

2)

Time (days)

MDL

ML


Conclusions

LEAF Method Validation

• Interlaboratory testing of triplicate tests from multiple laboratories

• LEAF methods can be performed with high degree of precision

5-13% Repeatability

14-28% Reproducibility

• Precision compares favorably to validated and accepted test methods

LEAF Methods as U.S. EPA SW-846 Standard Methods (Summer 2012)

Comparison to EU Tests • Analogous EU Test to LEAF methods provide analogous data

• Validation of LEAF methods can serve as a basis for completing the standardization

process for CEN and ISO methods


Acknowledgements

Participating Laboratories • Oak Ridge National Lab

• Pacific Northwest National Lab

• Savannah River National Lab

• ARCADIS-US, Inc.

• Test America, Inc.

• URS Corporation, Inc.

• Ohio State University

• University of Wisconsin (Madison)

• Missouri Univ. of Science & Tech.

• Vanderbilt University

• ECN

• DHI


Funding and Support • U.S. EPA, Office of Research and Development

• U.S. EPA, Office of Resource Conservation and Recovery

• U.S. DOE, Office of Environmental Management

• Consortium for Risk Evaluation with Stakeholder Participation (CRESP)

Supplemental Information


Method 1313 Overview

n chemical analyses

Ln LB LA

n samples

S2 Sn n B A

S1

0.01

0.1

1

10

100

1000

2 4 6 8 10 12 14 Leachate pH

Co

pp

er

[mg

/L]

Titration Curve and Liquid-solid Partitioning (LSP) Curve as Function of Eluate pH

30 May - 1 June 2012 28

Equilibrium Leaching Test

• Parallel batch as function of pH

Test Specifications

• 9 specified target pH values plus natural conditions

• Size-reduced material

• L/S = 10 mL/g-dry

• Dilute HNO3 or NaOH

• Contact time based on particle size 18-72 hours

• Reported Data Equivalents of acid/base added

Eluate pH and conductivity

Eluate constituent concentrations

WASCON, Gothenburg, Sweden


• Percolation through loosely-packed material

Test Specifications

• 5-cm diameter x 30-cm high glass column


• DI water or 1 mM CaCl2 (clays, organic materials)

• Upward flow to minimize channeling

• Collect leachate at cumulative L/S 0.2, 0.5, 1, 1.5, 2, 4.5, 5, 9.5, 10 mL/g-dry

• Reported Data Eluate volume collected



Method 1314 Overview air lock

eluant collection bottle(s) (sized for fraction volume)

Luer shut-off valve

eluant reservoir

end cap

end cap

1-cm sand layers

pump

subject material

Luer shut-off valve

Luer fitting

Luer fitting

N2 or Ar (optional)

Liquid-solid Partitioning (LSP) Curve as Function of L/S; Estimate of Pore Water Concentration


Method 1315 Overview Mass-Transfer Test

• Semi-dynamic tank leach test

Test Specifications

• Material forms monolithic (all faces exposed)

compacted granular (1 circular face exposed)

• DI water so that waste dictates pH

• Liquid-surface area ratio (L/A) of 9±1 mL/cm2

• Refresh leaching solution at cumulative times 2, 25, 48 hrs, 7, 14, 28, 42, 49, 63 days

• Reported Data Refresh time



1 Sample

n

analytical

samples

A1

L1

A2 An

L2 Ln

Δt1 Δtn

or

Monolith

Compacted Granular

n Leaching Intervals

Δt2

Flux and Cumulative Release as a Function of Leaching Time

Granular

Monolithic

0.001

0.01

0.1

1

10

100

1000

0.01 0.1 1 10 100C

r R

ele

ase [

mg

/m2]

Leaching Time [days]

Availability

MDL

ML


Method 1316 Overview


• Parallel batch as function of L/S

Test Specifications

• Five specified L/S values (±0.2 mL/g-dry) 10.0, 5.0, 2.0, 1.0, 0.5 mL/g-dry


• DI water (material dictates pH)

• Contact time based on particle size 18-72 hours

• Reported Data Eluate L/S



n chemical analyses

Ln LB LA

n samples

S2 Sn n B A

S1

Liquid-solid Partitioning (LSP) Curve as a Function of L/S; Estimate of Pore Water Concentration

30 May - 1 June 2012 31

0

20

40

60

80

100

120

0 2 4 6 8 10

Mo

lyb

den

um

[µ

g/L

]

LS Ratio [mL/g-dry]

WASCON, Gothenburg, Sweden

Interlaboratory Validation of Leaching Methods in the ...€¦ · Interlaboratory Validation of Leaching Methods in the Leaching Environmental Assessment Framework (LEAF) for Acceptance

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