copper sequestration using local waste products jim ippolito research soil scientist usda-ars...
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Copper Sequestration Using Local Waste Products
Jim IppolitoResearch Soil Scientist
USDA-ARSKimberly, ID
Presentation Outline
• Why worry about Cu in Idaho?
• Waste materials– Beneficial use
• Laboratory solution sorption studies
• Greenhouse soil sorption studies
• Conclusions
Why Worry About Cu in Idaho?
(nass.usda.gov/QuickStats/)
Idaho Dairy Cow Population
Year
1900 1920 1940 1960 1980 2000 2020
Dai
ry C
ow
s (i
n t
ho
usa
nd
s)
0
100
200
300
400
500
600
Local Wastes
• Can we beneficially reuseAmalgamated Sugar Co:
• Spent Lime Waste?– 274,000 tons/year
• Coal Ash?– 19,000 tons/year
• Goal is to sequester Cu
Laboratory Solution Sorption Study
• Fly ash or Lime waste– 1g into 50mL centrifuge tubes
• Add 50mL of increasing Cu solutions in pH buffers– Rates equivalent to 2500, 5000, 12500, 25000, 75000,
100000 mg Cu/kg– pH: 6, 7, 8, 9
• Shake for 1 month and analyze solution for Cu
• Replicated 3 times
Fly Ash Copper Adsorptionvs pH
(1 month shaking)
Cu Added (mg kg-1)
0 5000 10000 15000 20000 25000
Cu
Ad
sorb
ed (
mg
kg
-1)
0
5000
10000
15000
20000
25000 pH 6pH 7 pH 8 pH 9 1:1 Cu Adsorption
Fly Ash Copper AdsorptionpH 6
(1 month shaking period)
Cu Added (mg kg-1)
0 20000 40000 60000 80000 100000
Cu
Ad
sorb
ed (
mg
kg
-1)
0
20000
40000
60000
80000
100000
Observed Cu AdsorptionPredicted Cu Adsorption1:1 Cu Adsorption
Fly Ash Cu Adsorption = 26,060[1-e(-4.29e-5*Cu Added)]R2 = 0.86
Lime Waste Copper Adsorptionvs pH
(1 month shaking)
Cu Added (mg kg-1)
0 5000 10000 15000 20000 25000
Cu
Ad
sorb
ed (
mg
kg
-1)
0
5000
10000
15000
20000
25000 pH 6pH 7 pH 8 pH 9 1:1 Cu Adsorption
Lime Waste Copper AdsorptionpH 6
(1 month shaking period)
Cu Added (mg kg-1)
0 20000 40000 60000 80000 100000
Cu
Ad
sorb
ed (
mg
kg
-1)
0
20000
40000
60000
80000
100000
Observed Cu AdsorptionPredicted Cu Adsorption1:1 Cu Adsorption
Lime Waste Cu Adsorption = 44,640[1-e(-2.33e-5*Cu Added)]R2 = 0.96
Next Question
• Can lime waste sorb excess soil Cu?
Healthy Alfalfa Cu-Affected Alfalfa
Greenhouse Soil Cu Sorption
• Soil received:– 0, 250, 500, 1000 mg Cu/kg– Incubated for ~9 mo
• Lime waste– 0, 0.5, 1.0, 2.0% by weight (0,10,20,40 tons/ac)– Incubated for 3 months
• Alfalfa– 15 seeds/pot– 2.5 months of growth
Greenhouse Soil Cu Sorption
• Measured:– Plant yield– Plant Cu content– DTPA extractable soil Cu– Soil phases that Cu could be associated with:
• Soluble species/carbonates/cation exchange sites• Fe/Mn (hydr)oxides• Organics• Residuals
0% Lime Waste
0 250 500 1000
0.5% Lime Waste
0 250 500 1000
1% Lime Waste
0 250 500 1000
2% Lime Waste
0 250 500 1000
Soil pH = 7.9; biochar pH = 8.5
Cu added = 0, 250, 500, 1000 mg kg-1
Lime Waste added = 0, 0.5, 1, 2% by wt
Alfalfa Yield vs Cu Added
Cu Added (mg kg-1)
0 100 200 300 400 500
Alf
alfa
Yie
ld (
g)
0.0
0.5
1.0
1.5
2.0
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: NSCu Rate: p < 0.001Lime x Cu Rate: NS
Alfalfa Cu Content vs Cu Added
Cu Added (mg kg-1)
0 100 200 300 400 500
Pla
nt
Cu
Co
nce
ntr
atio
n (
mg
kg
-1)
0
2
4
6
8
10
12
14
16
18
20
22
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: p <0.001Cu Rate: p = 0.003Lime x Cu Rate: p = 0.045
DTPA Extractable Soil Cu vs Cu Added
Cu Added (mg kg-1)
0 200 400 600 800 1000
DT
PA
Ext
ract
able
Cu
(m
g k
g-1
)
0
100
200
300
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: NSCu Rate: p < 0.001Lime x Cu Rate: NS
Sequential Soil Cu ExtractionSoluble, Carbonate, Cation Exchange Associated Cu
Cu Added (mg kg-1)
0 200 400 600 800 1000
So
lub
le,
Car
bo
nat
e, C
atio
n E
xch
ang
e S
ite
Cu
(m
g k
g-1
)
0
50
100
150
200
250
300
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: p = 0.018Cu Rate: p < 0.001Lime x Cu Rate: p = 0.003
Iron and Manganese (Hydr)oxide Associated Cu
Cu Added (mg kg-1)
0 200 400 600 800 1000
Fe/
Mn
(H
ydr)
oxi
de
Cu
(m
g k
g-1
)
0
20
40
60
80
100
120
140
1600% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: p = 0.043Cu Rate: p < 0.001Lime x Cu Rate: p = 0.002
Organic and Sulfide Associated Cu
Cu Added (mg kg-1)
0 200 400 600 800 1000
Org
anic
an
d S
ulf
ide
Cu
(m
g k
g-1
)
0
20
40
60
80
100
120
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: p <0.001Cu Rate: p < 0.001Lime x Cu Rate: p = 0.019
Residual Cu
Cu Added (mg kg-1)
0 200 400 600 800 1000
Res
idu
al C
u (
mg
kg
-1)
0
20
40
60
80
100
120
140
0% Lime Waste 0.5% Lime Waste1% Lime Waste 2% Lime Waste
Lime Waste Rate: NS Cu Rate: p < 0.001Lime x Cu Rate: NS
Conclusions• Lime waste and fly ash sorb solution Cu
– Decreasing pH increases sorption– Fly Ash: ~26,000 mg Cu/kg– Lime Waste: ~45,000 mg Cu/kg
• Lime waste addition to Cu-laden soil– No improvement in alfalfa yield
• Decreased alfalfa Cu content
– No effect on extractable (i.e. DTPA) soil Cu– No major discernable differences in soil Cu phases
Conclusions
• The use of lime waste: – Appears to be a viable option for sequestering
solution copper.
– Would not be recommended for alkaline soils containing excess copper.
Thank you
Questions?
Jim Ippolito, Ph.D.Research Soil Scientist
USDA-Agricultural Research ServiceNorthwest Irrigation and Soils Research Laboratory
Kimberly, IdahoEmail: [email protected]
Phone: (208)423-6524