Disposal Strategies for CCA-Treated Wood August 13, 2003 National RCRA Conference Washington D.C.
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Disposal Strategies for CCA-Treated Wood August 13, 2003 National RCRA Conference Washington D.C.
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Transcript of Disposal Strategies for CCA-Treated Wood August 13, 2003 National RCRA Conference Washington D.C.
Disposal Strategies for CCA-Treated Wood
August 13, 2003National RCRA Conference
Washington D.C.
Funding Received from
Florida Center for Solid and Hazardous Waste Mngt.
Florida Power and LightSarasota County
Florida Department of Environmental Protection
Florida International University/NIEHSRutgers University/NIEHS
Helena Solo-Gabriele, Ph.D., P.E.,
Assoc. Prof., Civil/Environ. Engrg
Lora Fleming, M.D., Ph.D.
Assoc. Prof., Epidemiology/Ph.D.
Timothy Townsend, Ph.D.
Assoc. Prof., Environ/Solid Waste Engrg
Yong Cai, Ph.D.
Assist. Prof., Chemistry
Active Faculty Researchers
Students Supported on Project Sean Bennie Kenneth Brown Vandin Calitu Zhangrong Chen Brajesh Dubey Tim Franklin Kelvin Gary Myron Georgiadis Naila Hosein Kendiro Iida Gary Jacobi Jenna Jambeck Bernine Khan Monika Kormienko
Brian Messick Tom Moskal Jennifer Penha Donna May Sakura Catalina Santamaria Ajay Seth Tomoyuki Shibata Jin-Kun Song Kristin Stook Sheena Szuri Thabet Tolaymat Lakmini Wadanambi
UntreatedSYP
CCA-Treated0.25 pcf
CCA-Treated0.60 pcf
CCA-Treated2.5 pcf
Above GroundStructural PolesSaltwater Splash
Saltwater ImmersionPole/Pilings
Background
CCA Chromated Copper Arsenate
As toxic to humans, carcinogen
Cr toxic to humans, carcinogen
Cu toxic to aquatic organisms
ToxicityFn of Speciation
As(V) and As(III) toxic with As(III) more toxic
Cr(VI) more toxic than Cr(III)
Regulatory Issues
CCA currently under-going reregistration
Industry issued a nation-wide phase out for CCA used in residential applications
Exempt at federal level from being classified as a hazardous waste during disposal
Original Motivation For Project
Ash Disposal Problem
How Much CCA-Treated Wood is Disposed?
Disposal Model
Mass of As disposed to
landfills
volume of CCA-treated
wood produced
2.5% off-cut
Lumber, Timber, Fence, Other
Mass of As leached to
soil
Total Volume Disposed
10 – 20 years
35 – 45 years
Disposal Sub-model
2
60%
Lumber
Timber
Fences
Other
Utility poles
Utility Poles
40%
100%
25 – 35 years
0
5
10
15
20
25
30
35
40
4519
60
1964
1968
1972
1976
1980
1984
1988
1992
1996
2000
2004
2008
2012
2016
2020
2024
2028
2032
2036
2040
Year
Vol
ume
(106
ft3)
Phase out
Production
Disposal
How Much CCA-Treated Wood in Florida?
(Preliminary)
Amount of CCA-Treated Wood To Be Discarded
Cumulative Volume Imported = 660 million cubic feet Volume in Service = 440 million cubic feet
Statistics for the Year 2003 (Florida)
216,000 miles of 2 x 4’s
100 yds x 50 yds x 2.7 miles
9 timesaround
0
5000
10000
15000
20000
25000
30000
35000
40000
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
2025
2030
2035
2040
Year
Cum
ulat
ive
Mas
s of
As
(ton
s)
Cumulative Production
Cumulative Disposal
In-Service Quantity
How Much CCA-Treated Wood In Florida?
(Preliminary)
C&D LandfillMSW Landfill
C&D Debris Recycling Facilities
CCA-WoodRemoved
from Service
Processed Wood (6% CCA in 1996)
Land Application
Wood Fuel Facility Ash
Background
Research conducted found CCA-treated wood in C&D waste piles
6% in 1996 (12 C&D facilities) 9 to 30% in 1999 (3 C&D facilities) 22% in 2001 (1 C&D facility studied extensively)
Background
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.619
80
1982
1984
1986
1988
1990
1992
1994
1996
1998
bill
ion
cu
bic
fee
t
Untreated
Treated
(From SFPA)
U.S. Statistics for Southern Pine Production
C&D LandfillMSW Landfill
C&D Debris Recycling Facilities
CCA-WoodRemoved
from Service
Processed Wood (6% CCA in 1996)
Land Application
Wood Fuel Facility Ash
Disposal Through Wood Ash
Industrial Furnace
Grate
Ash Catch Pan
Shred
Ashing
Leaching of Wood Ash - Total
0.01
0.1
1
10
100
1000
10000
A B C D E F G
Ars
enic
in L
eac
ha
te (
mg
/L)
TCLPSPLP
TC Limit
GWCTL
Arsenic
Wood Ash
The presence of CCA-treated wood as 5% of the wood mix caused the ash to be characterized as hazardous.
Leaching of Wood Ash - Speciation
0
50
100
150
200
250
300
350
400
Untreated-ash 0.25 pcf-ash 0.6 pcf-ash Pole-ash 2.5 pcf-ash C&D 1-ash C&D 3-ash
As
Con
cen
trat
ion
(mg/
L)
Avg. Total (ICP-AES)
Avg. Total (AFS) = AsIII + AsV
Avg. As V (AFS)
Avg. As III (AFS)
As,SPLP
Leaching of Wood Ash – Speciation
0
10
20
30
40
50
60
Untreated-ash 0.25 pcf-ash 0.6 pcf-ash Pole-ash 2.5 pcf-ash C&D 1-ash C&D 3-ash
Cr
Con
cent
ratio
n (m
g/L
)
Avg. Total Cr
Avg. Cr VI
Avg. Cr III
Cr,SPLP
Leaching of Wood Ash – Speciation
R2 = 0.68
0
10
20
30
40
50
0 5 10 15
pH
Cr C
once
ntra
tion
(mg/
L) C&D 3-ash
Pole-ash
0.25 pcf-ash
C&D 1-ash
2 .5 pcf-ash 0.6 pcf-ash
Cr,SPLP
C&D LandfillMSW Landfill
C&D Debris Recycling Facilities
CCA-WoodRemoved
from Service
Processed Wood (6% CCA in 1996)
Land Application
Wood Fuel Facility Ash
Leaching of Mulch
Samples No. No. Exceeding GWCTL for As
No. Exceeding GWCTL for Cr
C&D Debris 20 18 5
Yard Waste 3 1 1
Colored Mulch
3 2 0
Vegetative Mulch
3 0 0
Leaching of Mulch
# Generic Description As
(mg/kg) %CCA 4 Red Colored Mulch, Open Bin 118 4.2-5.8
33 Red Colored Mulch, Bagged BDL < 0.05 17 Non-colored Mulch (Pine Bark) BDL < 0.05 19 Non-colored Mulch (Pine Bark) BDL < 0.05 20 Non-colored Mulch (Pine Bark) BDL < 0.05 18 Non-colored Mulch (Cypress) BDL < 0.05 32 Mulch from Playground BDL < 0.05 16 Refuse Derived Fuel 4 0.2-0.3% 28 Soil – Wood Blend 1 < 0.05
BDL = Below Detection Limit
Results to Date for Samples Collected as Part of the 2002 – 2003 Study
Mulch
Must contain < 0.2 % CCA-treated wood in order to pass GWCTL
C&D LandfillMSW Landfill
C&D Debris Recycling Facilities
CCA-WoodRemoved
from Service
Processed Wood (6% CCA in 1996)
Land Application
Wood Fuel Facility Ash
TCLP Results – Total
0
2
4
6
8
10
12
14
16
18
20
A B C D E F G H I J K L M N O P Q
As
(m
g/l
)
New Wood Used Wood
TCLPLimit
Leaching - Speciation
SPLP 0.05 mg/L
As(III)As(V)Total As
0
2
4
6
8
10
12
A B C D E F G H I J K L M N O P Q R S T V
Conce
ntr
ati
on
(m
g/L
)
New Weathered
T V
Possible Solutions
“Short–Term” Solution• Develop Strategies By Which to Better
Manage CCA-Treated Wood
“Long-Term” Solution• Use Wood Treated With Non-Arsenical
Preservatives
Long-term Solution
Use Wood Treated With Non-Arsenical Preservatives
Alternative Chemicals
Contain no arsenic
Have been used commercially to some extent
Standards provided by the AWPA
Waterborne preservative
Chemicals Considered
Phase I: Alternative Chemicals
AAC: Alkyl Ammonium Compound (a.k.a. DDAC) ACC: Acid Copper Chromate ACQ: Ammoniacal Copper Quat Borates CBA: Copper Boron Azole CC: Ammoniacal Copper Citrate CDDC: Copper Dimethydithiocarbamate
Chemicals Initially Considered
General Comments About Remaining 4 Alternative Chemicals
Efficacy Depletion/Leaching Corrosion Mechanical Properties Costs
Just as Effective for Standardized Products
Leach less As but more Cu
Similar to CCA
Some require SS fasteners
Cost 10 to 30% more
0
2
4
6
8
10
DI TCLP SPLP SW
Ars
en
ic C
on
ce
ntr
ati
on
(m
g/L
) CCA-1 CCA-2
Leaching Tests
0
10
20
30
40
50
60
70
CCA-1 CCA-2 ACQ CBA CC CDDC
Co
pp
er
Co
nce
ntr
ati
on
(m
g/L
)
SPLPSynthetic Rainfall
Toxicity Tests
LessToxic
0.1
1
10
100
1 10 100 1000Copper Concentration (mg/L)
EC
50 (
%)
EC50 Cu = 3.8 mg/l
EC50 Cu = 0.076 mg/l
MicrotoxRegression Line
R2 = 0.307CCA
CDDC
CBA
ACQ
CC
“Short-term” Solution for the Disposal Problem
Develop Sorting Technologies
C&D LandfillMSW Landfill
C&D Debris Recycling Facilities
CCA-WoodRemoved
from Service
Processed Wood (6% CCA in 1996)
Land Application
Wood Fuel Facility Ash
Add a WoodSorting Step
CCA-Treated Wood
99.9% UntreatedWood
Objective
Construct and Operate an On-Line System for Sorting Treated From Untreated Wood
Most of the time, the identification of CCA-treated wood is difficult, especially for wood from demolition.
Sorting Technologies
Low Capital Cost, Labor Intensive
Chemical stainsUntreated Treated
Suitable for On-Line System, High Capital Costs X-ray Technology (XRF)
Laser Technology (LIBS)
Sorting Technologies
DETECTORS
laser
x-ray
Laser configuration
LaserTo PC
Wood
Plasma Caused By Laser
Output signal for detection of treated wood
Strobe LightOn -Positive
LIBS Spectrum of CCA-treated Wood
0
2000
4000
6000
8000
10000
12000
14000
410 415 420 425 430 435 440
Em
issio
n I
nte
nsity
Wavelength (nm)
Calcium(422.67)
Chromium425.54427.48428.97
Weathered
Analysis of single laser shots
Treated Lumber
UntreatedLumber
100%accuracy
99%accuracy
10-shotaverage
92%accuracy
95% accuracy
Single-shotanalysis
35.069.1 44.198.3 Cr Signal
Summary of LIBS Results
Successfully detect CCA-treated wood by presence of chromium in the field
Indicator strobe enables real-time, on-line sorting with accuracy approaching 100%
Some inefficiencies noted in this study wet wood and surface coatings. Can be overcome with a more powerful laser.
X-ray Detector
¾”
Treated vs. Untreated Wood
0
100
200
300
400
No paint Thompson'sWaterseal
Oilbased paint WoodPreservative
WaterbasedWood Stain
WaterbasedExterior Paint
As
Co
un
ts
Treated
Untreated
Dry vs. Wet Treated Wood
0
100
200
300
400
No paint Thompson'sWaterseal
Oilbased paint WoodPreservative
WaterbasedWood Stain
WaterbasedExterior Paint
As
Co
un
ts
Dry
Wet
Alternative Chemicals
0
100
200
300
400
500
CCA Untreated CDDC ACQ CC CBA
As
Co
un
ts
1400
Distance readings
0
200
400
600
800
1000
1200
1400
Distance (in)
As
Co
un
ts
0 211/80211/8
Treated
Untreated
XRF Summary
•Advantages Very consistent. It can not only differentiate between
treated and untreated wood but gives the actual amount treated in specific units.
•Disadvantages Limited to no more than 1” distance.
Sorting Summary
Both X-ray & Laser Methods Are Very Promising
Improvements, Develop Logic Between Detector and Shear Arm
Full Scale Field Demonstration Recommended to Further Substantiate Performance and Cost Effectiveness
Ultimate Disposal?
Lysimeters 2 Monofills / 2 C&D / 2 MSW
Untreated
(mg/L)
Treated
(mg/L)
Wood Monofill
(100% wood)
< 0.02 5 – 43
As(III), As(V)
C&D Waste
(34% wood)
<0.06 0.4 – 1.8
As(III), As(V) , DMAA, MMAA
MSW
(2% wood)
< 0.7 0.4 – 2.3
As(III) , As(V), DMAA, MMAA
Overall Recommendations Arsenic and Chromium burden will continue to increase even with
proposed industry phase out
Switch to alternative chemicals + for terrestrial systems - for aquatic ecosystems (Cu)
Sorting will be necessary At Source At C&D Facilities
Disposal Within Lined Landfills Preferred Over Unlined Landfills, Mulch, and Ashing
