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

Transcription

1 Interlaboratory Validation of Leaching Methods in the Leaching Environmental Assessment Framework (LEAF) for Acceptance by U.S. EPA Andrew GARRABRANTS, David KOSSON, Rossane DELAPP, Hans VAN DER SLOOT 2, Leonard STEFANSKI 3, Susan THORNELOE 4, Gregory HELMS 5, Mark BALDWIN 5, and Peter KARIHER 6 Civil and Environmental Engineering, Vanderbilt University, Nashville, TN, USA 2 Hans van der Sloot Consultancy, 72 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

2 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 - June 202 WASCON, Gothenburg, Sweden 2

3 U.S. Materials Testing (Historically) 960s-990s 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) 990s 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 30 May - June 202 WASCON, Gothenburg, Sweden 3

4 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 - June 202 WASCON, Gothenburg, Sweden 4

5 Leaching Environmental Assessment Framework LEAF is a collection of Four leaching methods Data management tools Leaching assessment approaches LeachXS Lite TM 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 30 May - June 202 WASCON, Gothenburg, Sweden 5

6 LEAF Leaching Methods Method 33 Method 34 Method 35 Method 36 Liquid-Solid Partitioning as a Function of Eluate ph using a Parallel Batch Procedure Liquid-Solid Partitioning as a Function of Liquid-Solid Ratio (L/S) using an Up-flow Percolation Column Procedure Mass Transfer Rates in Monolithic and Compacted Granular Materials using a Semi-dynamic Tank Leaching Procedure 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. 630 May - June 202 WASCON, Gothenburg, Sweden 6

7 LEAF and EU Methods Parameter LEAF Method EU Method EU Applications ph-dependence Method 33 CEN/TS 4429 CEN/TS 4997 ISO/TS 4997 Percolation Method 34 CEN/TS 4405 CEN/TC35/TS-3 ISO/TS Mass Transport Method 35 CEN/TS 5683 CEN/TC35/TS-2 NEN 7347 (Dutch) NEN7348 (Dutch) L/S dependence Method 36 EN waste waste, mining waste, construction products waste, mining waste, construction products soil, sediments, compost, sludge waste, mining waste construction products soil, sediments, compost, sludge monolithic waste monolithic construction products monolithic waste granular waste and construction products, Many of These Methods are not yet Standardized Pending Validation 30 May - June 202 WASCON, Gothenburg, Sweden 7

8 Validation of LEAF Test Methods 30 May - June 202 WASCON, Gothenburg, Sweden 8

9 LEAF Test Methods Validation Interlaboratory Validation Program EPA Guidance for Methods Development and Methods Validation for the RCRA Program ASTM E69 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 30 May - June 202 WASCON, Gothenburg, Sweden 9

10 Participating Laboratories Number of labs varied with test method, availability and support Method 33/36 targeted 0 laboratories Method 35 targeted 0 laboratories Method 34 targeted 7 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) 30 May - June 202 WASCON, Gothenburg, Sweden 0

11 Coal Combustion Fly Ash Collected for EPA study Selected for validation of Method 33 Method 36 Solidified Waste Analog Created at Vanderbilt University Blast Furnace Slag, Class C Fly Ash, Type I/II Cement, Metal Salts Selected for validation of Method 33 Method 36 Method 35 Study Materials Contaminated Field Soil Copper smelter site Selected for validation of Method 33 Method 36 Method 35 Method 34 Brass Foundry Sand Selected for validation of Method 35 Method May - June 202 WASCON, Gothenburg, Sweden

12 Selenium (mg/l) Selenium (mg/l) Data Processing Log 0 -Transform of Test Output Method 33 Eluate Concentration Method 34 Eluate Concentration, Cumulative Mass Release Method 35 Interval Mass Flux, Cumulative Mass Release Method 36 Eluate Concentration ph Linear Interpolation and Extrapolation Collected Data Shows Variability Brings Data to Specified ph, L/S or Time Consistency in Comparisons 0 Implications for Compliance Standards target ph 30 May - June 202 WASCON, Gothenburg, Sweden 2

13 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 (RSD r ) Within-Lab Variance Reproducibility Relative Standard Deviation (RSD R ) Overall Variance RSD RSD r R y s r 00% sr 00% y Reproducibility Limit Interval (RL) Based on reproducibility limit (R) Interval within which reproducibility data is considered to be the same with 95% confidence R 2. 8 s R RL log( y) log( R) 30 May - June 202 WASCON, Gothenburg, Sweden 3

14 Arsenic (mg/l) As Reproducibility (%) Method 33 Validation Examples Coal Combustion Fly Ash Reproducibility 00 0 M33 EaFA Mean Overall SD Between Lab SD Within Lab SD CFS RSD-R EaFA RSD-R SWA RSD-R 0. 0 ICP-OES RSD Target ph Target ph Study Materials CFS EaFA SWA Contaminated Field Soil Coal Combustion Fly Ash Solidified Waste Analog 30 May - June 202 WASCON, Gothenburg, Sweden 4

15 Boron Release RSD R (%) Aluminum Release RSD R (%) Aluminum RSD R (%) Barium Flux RSD R (%) Evaluation Basis Percolation Column 00 Concentration in 9 th Fraction (L/S 0 ) Mass Transfer 000 Flux in 4 th Interval (7-day cumulative time) 00 Mean Flux 2 nd - 4 th Intervals (excludes washoff) 0 00 ICP-OES RSD M34 CFS RSD-R M34 JaFS RSD-R 0. 0 L/S (L/kg) M34 CFS RSD-R M34 JaFS RSD-R Concentration in 2 nd Fraction (L/S 0.5 ) Release at End of Test (L/S = 0 ml/g-dry ) 00 0 ICP-OES RSD Mean Flux 2 nd - 9 th Intervals M35 CFS RSD-R (excludes washoff) M35 SWA RSD-R Time (days) Release after 4 th Interval (7-day cumulative time) 0 ICP-OES RSD Release through 2 nd Fraction (L/S = 0.5 ml/g-dry ) 0. 0 L/S (L/kg) 0 ICP-OES RSD M35 CFS RSD-R M35 SWA RSD-R Release at End of Test (63-day cumulative time) Time (days) 30 May - June 202 WASCON, Gothenburg, Sweden 5

16 LEAF Method Precision Method Test Output RSD r (%) RSD R (%) Method 33 Eluate Concentration (average over ph range) 0 26 Method 34 Method 35 Eluate Concentration (9 th fraction at L/S=0) Mass Release (cumulative to L/S=0.5) Mass Release (cumulative to L/S=0) Interval Flux (average excluding wash-off) Mass Release (cumulative to 7-days) Mass Release (cumulative to 63-days) Method 36 Eluate Concentration (average over L/S range) May - June 202 WASCON, Gothenburg, Sweden 6

17 RSD r (%) RSD R (%) Precision Comparison (ph-dependence Tests) Repeatability Reproducibility Max SWA ph 2 RSD r = 30% Max CFS ph 3 RSD r = 4% Max SWA ph 2 RSD R = 500% Max CFS ph 3 RSD R = 300% Max RSD R = 24% Max RSD R = 8% EaFA SWA CFS EN EaFA SWA CFS EN TCLP Method Precision Method 34 Eluate Concentration (2 ph 3) EN2457 Eluate Concentration (natural ph) TCLP Eluate Concentration (acetic acid buffer) 30 May - June 202 WASCON, Gothenburg, Sweden 7

18 RSD r (%) RSD R (%) 00 Repeatability 80 Precision Comparison (Percolation Tests) Reproducibility Max RSD R = 39% Max RSD R = 8% CFS JaFS DIN9528 CFS JaFS DIN9528 TCLP Method Precision Method 34 Cumulative Release at L/S = 0 L/kg DIN 9528 Cumulative Release at L/S = 4.0 L/kg TCLP Eluate Concentration (L/S = 20 L/kg) 30 May - June 202 WASCON, Gothenburg, Sweden 8

19 RSD r (%) RSD R (%) Repeatability Precision Comparison (Mass Transfer Tests) Reproducibility Max RSD R = 8% SWA CFS NEN 7345 SWA CFS NEN 7345 TCLP Method Precision Method 35 NEN 7345 TCLP Cumulative Release after 63 days Cumulative Release after 6 days Eluate Concentration 30 May - June 202 WASCON, Gothenburg, Sweden 9

20 RSD r (%) RSD R (%) Repeatability Precision Comparison (L/S-dependence Tests) Reproducibility Max SWA L/S 0.2 RSD R = 75% Max RSD R = 24% Max RSD R = 8% EaFA SWA CFS EN EaFA SWA CFS EN TCLP Method Precision Method 36 EN TCLP Eluate Concentration (0.5 L/S 0 L/kg) Eluate Concentration (L/S = 0 L/kg) Eluate Concentration (L/S = 20 L/kg) 30 May - June 202 WASCON, Gothenburg, Sweden 20

21 Comparison of LEAF and EU Test Results 30 May - June 202 WASCON, Gothenburg, Sweden 2

22 Molybdenum (mg/l) Molybdenum (mg/l) Molybdenum (mg/l) Chromium (mg/l) Chromium (mg/l) ph-dependence Tests Coal Combustion Fly Ash Solidified Waste Analog L-CEN/TS4429-A L-CEN/TS4429-B L-CEN/TS4429-C L-CEN/TS4997-A L2-CEN/TS4997-A L2-CEN/TS4997-B L2-CEN/TS4997-C M33 Mean M33 95% RL ph ph 0 0 Solidified Waste Analog 0 Contaminated Field Soil Coal Combustion Fly Ash ph ph ph 30 May - June 202 WASCON, Gothenburg, Sweden 22

23 Copper Release (mg/kg) Molybdenum Release (mg/kg) Zinc Release (mg/kg) Boron Release (mg/kg) Calcium Release (mg/kg) Percolation (Column) Tests Contaminated Field Soil L-CEN/TS4405-A L-CEN/TS4405-B L-CEN/TS4405-C M33 Mean M33 95% RL L/S (L/kg) L/S (L/kg) L/S (L/kg) L/S (L/kg) L/S (L/kg) 30 May - June 202 WASCON, Gothenburg, Sweden 23

24 Boron Release (mg/m 2 ) Iron Release (mg/m 2 ) Antimony Release (mg/m 2 ) Barium Release (mg/m 2 ) Calcium Release (mg/m 2 ) Time (days) 00 Mass Transfer Tests Time (days) 0 Solidified Waste Analog 000 L-CEN/TS5863-A L-CEN/TS5863-B L-CEN/TS5863-C L-NEN 7375-A L-NEN 7375-B L-NEN 7375-C M33 Mean M33 95% RL Time (days) Time (days) Time (days) 30 May - June 202 WASCON, Gothenburg, Sweden 24

25 Conclusions LEAF Method Validation Interlaboratory testing of triplicate tests from multiple laboratories LEAF methods can be performed with high degree of precision 5-3% Repeatability 4-28% Reproducibility Precision compares favorably to validated and accepted test methods LEAF Methods as U.S. EPA SW-846 Standard Methods (Summer 202) 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 30 May - June 202 WASCON, Gothenburg, Sweden 25

26 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) 30 May - June 202 WASCON, Gothenburg, Sweden 26

27 Supplemental Information 30 May - June 202 WASCON, Gothenburg, Sweden 27

28 Copper [mg/l] Equilibrium Leaching Test Parallel batch as function of ph Method 33 Overview Test Specifications 9 specified target ph values plus natural conditions Size-reduced material L/S = 0 ml/g-dry Dilute HNO 3 or NaOH Contact time based on particle size 8-72 hours Reported Data Equivalents of acid/base added Eluate ph and conductivity Eluate constituent concentrations Titration Curve and Liquid-solid Partitioning (LSP) Curve as Function of Eluate ph n samples S n chemical analyses A L A S 2 S n B n L B L n Leachate ph 30 May - June 202 WASCON, Gothenburg, Sweden 28

29 Method 34 Overview Equilibrium Leaching Test Percolation through loosely-packed material Test Specifications 5-cm diameter x 30-cm high glass column Size-reduced material DI water or mm CaCl 2 (clays, organic materials) Upward flow to minimize channeling Collect leachate at cumulative L/S 0.2, 0.5,,.5, 2, 4.5, 5, 9.5, 0 ml/g-dry Reported Data Eluate volume collected Eluate ph and conductivity Eluate constituent concentrations N 2 or Ar (optional) air lock eluant collection bottle(s) (sized for fraction volume) Luer fitting eluant reservoir -cm sand layers pump Luer fitting Luer shut-off valve end cap subject material end cap Luer shut-off valve Liquid-solid Partitioning (LSP) Curve as Function of L/S; Estimate of Pore Water Concentration 30 May - June 202 WASCON, Gothenburg, Sweden 29

30 Cr Release [mg/m 2 ] Mass-Transfer Test Semi-dynamic tank leach test Method 35 Overview Test Specifications Material forms monolithic (all faces exposed) Monolith or Compacted Granular Sample compacted granular ( circular face exposed) DI water so that waste dictates ph Liquid-surface area ratio (L/A) of 9± ml/cm 2 Refresh leaching solution at cumulative times 2, 25, 48 hrs, 7, 4, 28, 42, 49, 63 days Reported Data Refresh time Eluate ph and conductivity Eluate constituent concentrations Flux and Cumulative Release as a Function of Leaching Time Δt A L n Leaching Intervals A 2 L Δt 2 n analytical samples Availability A n L n Δt n Monolithic Granular Leaching Time [days] 30 May - June 202 WASCON, Gothenburg, Sweden 30

31 Molybdenum [µg/l] Method 36 Overview Equilibrium Leaching Test Parallel batch as function of L/S Test Specifications Five specified L/S values (±0.2 ml/g-dry) 0.0, 5.0, 2.0,.0, 0.5 ml/g-dry Size-reduced material DI water (material dictates ph) Contact time based on particle size 8-72 hours Reported Data Eluate L/S Eluate ph and conductivity Eluate constituent concentrations n samples S n chemical analyses A L A S 2 S n n B L B L n Liquid-solid Partitioning (LSP) Curve as a Function of L/S; Estimate of Pore Water Concentration 30 May - June 202 WASCON, Gothenburg, Sweden LS Ratio [ml/g-dry]