Success of Willow Grown in Amended Solvay Waste as a Landfill
Cover System
D.J. Daley1, T.A. Volk2, and L.P. Abrahamson2
1Department
of Environmental Resources and Forest Engineering, 2Department of Forest and Natural Resources Management
State University New York, College of Environmental Science and Forestry, Syracuse, NY, 13210
Project Goals
Quantify the impact of shrub willow biomass crops on the water balance of the Solvay settling basins.
Model and design an alternative evapotranspiration (ET) cover system to reduce percolation through the settling basin.
Transform the settling basins into a productive area for renewable energy and improve its ecological function and
value.
Site Description
Soda ash was produced near Syracuse, NY
using locally-mined salt brine and limestone
in the Solvay process from 1881 to 1986.
Process residues (Ca, Mg, Na salts) were
slurried and dewatered in approximately
600-ha of settling basins adjacent to
Onondaga Lake (Figures 1&2).
Solvay waste is characterized by elevated
pH (~11.5) and EC, low nutrients and little
structure. Percolation from the basins
impacts groundwater and adjacent
waterways.
An alternative evapotranspiration (ET) cover
using fast growing shrub willows has been
investigated since 2004 to reduce
percolation.
Full-Scale Demonstration (SB14)
A 10-acre demonstration of the willow-based ET cover system started
in 2008 with regulatory oversight. Organic amendments (biosolids and
yard waste) were added at volumetric rates of 2.5:1 and 1.25:1
(waste:amendment). Water and heat fluxes in the canopy and shallow
soil are measured and compared to SHAW model predictions.
Monitoring includes I-buttons for soil and canopy air temperature and
RH; IR thermometer for leaf temperature; soil moisture and
percolation.
Water Budget Monitoring and
Modeling (2004 – 09)
Willow Field Trials (2004 – 08)
Field trials were conducted on SB13 to assess the survival,
growth and production of different shrub willow varieties planted
in Solvay waste mixed with organic amendments.
Locally available organic amendments were tested to determine
which ones would effectively support willow growth (Figure 4).
The water budget is modeled using field data and the onedimensional Simultaneous Heat and Water (SHAW) model to
simulate growing conditions over a 30-year time period and to
compare ET with conventional cover system designs and
predicted performance using the HELP model.
120
2004 L25
2005 L25
2004 L50
**
100
2005 L50
*
*
Survival (%)
80
60
40
Cumulative Precipitation & Percolation (2009)
Percolation & Precipitation (2009)
20
600
1
6
98
3
7 -7
7
98
7
0 -2
3
98
7
1 -2
6
98
7
1 -3
1
98
8
2 -3
10.0
4
S
5
36
S
V1
S
1
X6
S
4
X6
0
9.0
500
Figure 3. First year survival and growth for willow varieties on SB13
where organic amendments were incorporated in early 1990s.
10
8.0
Precipitation & Percolation (mm)
400
50
25 cm cuttings
50 cm cuttings
Cumulative Preci p
Perc Plot A1
300
Perc Plot A2
Perc Plot B1
Perc Plot B2
200
20
7.0
30
6.0
5.0
40
4.0
50
Precipitation (mm/day)
98
-6
01
Average Evacuation (mm/day)
0
3.0
60
PLOT A1
PLOT A2
PLOT B1
PLOT B2
Precipi tati on
2.0
Figure 1. Southerly view of settling Basins 13 (left),
and 14 (right, with unvegetated area).
Biomass (odt ha-1 3-yr-1)
40
100
Figure 6: Monitoring water fluxes using permeameter, wicking and pan
lysimeters and sap flow sensors generates data for model calibration and
performance monitoring.
30
20
10
70
1.0
0
9060
9080
9100
9120
9140
9160
9180
9200
9220
9240
9260
9280
0.0
9070
9090
9110
9130
9150
9170
9190
9210
9230
9250
80
9270
Julian Date yddd (beginning 3/11/09, ending 9/27/09)
Julian Date yddd (beginning 3/11/09, ending 9/27/09)
Figure 8: Preliminary results from modified suction pan lysimeters
indicate percolation from 45-cm depth is <5% of total precipitation for
growing season. Percolation is responsive to soil moisture and shortduration, intense precipitation events.
SV1.
S365.
SX64.
SX61.
9882-34.
9871-31.
9871-26.
9870-23.
SV1
9837-77.
S365
SX64
SX61
98101-66.
9882-34
9871-31
9871-26
9870-23
9837-77
98101-66
0
Willow Variety
Figure 4. Aboveground biomass production exceeded 30 oven dry
tons/ha after three years of growth, which is comparable to willow
production rates on agricultural land in central NY.
A.
B.
C.
D.
Time Period
Start
Time Period
End
Day
Date
Day
156
5-Jun
178
This project is supported by
3.7
Total
(mm)
Mean
(mm/d)
78.9
3.6
Mean
Difference
(P-M) (mm)
(-) indicates model under
prediction
-3.1
14-Jul
200
19-Jul
19.7
3.9
29.3
5.9
9.6
205
24-Jul
25Aug
27Sep
23Oct
212
31-Jul
31.9
4.6
26.5
3.8
-5.4
248
5-Sep
33.8
3.1
5.8
0.5
-28.0
281
8-Oct
27Oct
32.1
2.9
12.3
1.1
-19.8
3.2
0.8
1.2
0.3
-1.9
237
296
Figure 5. In 2005, wastewater biosolids and yard waste were delivered
(A), applied (B) and incorporated (C) into research trials on SB13. The
area was planted in 2006 with two willow varieties (D). Information
from this trial was used in the design of the full scale demonstration
that started in 2008 on SB14.
82.0
SHAW Predicted
Transpiration
195
270
Figure 2. Solvay process waste lacks
structure, labile organic matter and nutrients
for long-term vegetation support. Sparse
stands of grasses and trees grow slowly on
some areas.
Date
27Jun
Measured Sap
Flow
Mean
Mean
Total
Daily
(mm) (mm/d)
300
Figure 7: SHAW model calibration using sap flow and predicted
transpiration rates for 2006. The MD and RMSE for the calibration
periods in 2006 are 0.07 and 0.085, respectively.
Figure 9: Field measurements indicate cooling effect of SX-64 canopy
on shallow (25 cm) soil temperature. Model calibration is underway.
Figure 10: Diurnal variations in Canopy Air Temperature (below
canopy @0.5m, within @1.5m and above @3.0m) are matched
by SHAW simulation of variety 9882-34 (27 to 31 August 2009).