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Aerobic vs Anaerobic BioreactorAerobic vs. Anaerobic Bioreactor Landfill Case Study: the New
River Regional Landfill
Presented at SWANA’s 6th Annual Landfill Symposia
San Diego CASan Diego, CAJune 18-20, 2001
D b R R i h t PhDDebra R. Reinhart, PhDTimothy Townsend, PhD
P t ti O iPresentation Overview
• Brief overview of NRRL bioreactor projectproject
• Flammability issuesC t i• Cost issues
• Moisture balance issues• Waste degradation issues• Process control impactsProcess control impacts
ProjectProject Location
Cell 3Cells 1 & 2
Bioreactor
Bi t C tBioreactor Components
• Leachate Collection System ModificationsModifications
• Leachate/Air InjectionG C ll ti• Gas Collection
• Geomembrane Cap
Top of LandfillCluster Well Sk t hSketch
• Three Wells
• Spacing 3-5 ft
• Maintain 10 ft distancefrom top of sand drainage layer todrainage layer to bottom of the well
fTop of Sand DrainageBlanket
10 ft
Instrumentation and Injection W llWells
CN2CL2
CN2
CO3
CM3
CN4
900
New River Regional Landfill Bioreactor Project
Injection700
800InjectionWells
500
600
CD2
CF3
CC3
CD4CE5
CC5
CD6
CE7
CC7
CD8
300
400
CL2
CJ2
C 3
CH2
CK3
CF2
CI3
CL4
C3WCG3
CJ4
CH4
CK5
CF4
CL6
CI5
CG5
CJ6
CH6
CK7
CF6
CI7
CL8
CG7
CJ8
CH8
CF8
100
200
CN2CO3
CM3
CN4CO5
CM5
CN6CO7
CM7CN8
0 100 200 300 400 500 600 700 800
0
New River Regional LandfillLocation: Union County, Florida
Monitoring WellInjection Well
Bioreactor Landfill BoundaryAccess Road
Legend Injection Wells Location Map Sheet Nº
2/3
File: NR_xy final plot.srf Date: 05/30/01Scale: 1:125Units:English<ft>
New River Regional Landfill Bioreactor Project
900
Instrumentation700
800InstrumentationWells
500
600
MD3 MD4
ME5
MC5
MD6 MD8
MC9
300
400
ML3
MJ3
ML4
MH3
MJ4
MF3
ML5
MK5
MD3
MF4
MI5
MK6
MG5
MI6
ME5
MH6
MK7
MF6
MI7
ML8
MG7
MJ8
ME7
MH8
MF8
MI9
MF9G3W G3E
100
200MO3
MN4
ME3
MO5 MH4
MM6 MM7
MN8
MM9L6WM3W M3A
L7E
0 100 200 300 400 500 600 700 800
0
New River Regional LandfillLocation: Union County, Florida
Monitoring WellInjection Well
Bioreactor Landfill BoundaryAccess Road
Legend Monitoring Wells Location Map Sheet Nº
3/3
File: NR_xy final plot.srf Date: 05/30/01Scale: 1:125Units:English<ft>
New River Regional Landfill Bioreactor Demonstration ProjectCross Section on Injection Cluster Wells C8 (x=600)Cross Section on Injection Cluster Wells C8 (x=600)
210
220
CN8CL8
CJ8 CH8 CF8
190
200
CD8
160
170
180
Elev
atio
n <f
t>
140
15010 ft
120
130
-100 0 100 200 300 400 500 600 700 800 900
Y <ft>
Landfill Surface Well Bottom Safety Zone Bottom Liner
M it iMonitoring
• Leachate• Landfill Gas• Waste Properties• Settlement
I t t tiInstrumentation
• Head on Liner• Total Waste Load• Total Waste Load• Leachate Flow• Landfill Temperature• Landfill Moisture
Content
9.0010.00
es)
es)
4 005.006.007.008.009 00
epth
(inc
hep
th (i
nch
0 001.002.003.004.00
Liqu
id D
eLi
quid
De
-1.000.00
Leachate Collection pipeLeachate Collection pipe
A 3A 3--D view of head built on the linerD view of head built on the liner
Leachate Collection pipeLeachate Collection pipe
66 66
55
66
55
66
(inch
)(in
ch)Rainfall vs. Time Avg. Head on Liner vs. Time
HELP Model
44
fall
(inch
)fa
ll (in
ch)
44
d on
Lin
er
d on
Lin
er
22
33
Rai
nfR
ainf
22
33
Avg.
Hea
dAv
g. H
ead
o
11 11
AA
000303--JulJul 0303--AugAug 0303--SepSep 0404--OctOct 0404--NovNov 0505--DecDec 0606--JanJan 0606--FebFeb 1212--MarMar 1616--AprApr 1717--MayMay
Time (days)Time (days)
00
Moisture Sensors
900
New River Regional Landfill Bioreactor ProjectTemperature
700
800
500
600
300
400
100
200
0 100 200 300 400 500 600 700 800
0
New River Regional LandfillLocation: Union County, Florida
Monitoring WellInjection Well
Bioreactor Landfill BoundaryAccess Road
Legend General Temperatute SketchInjection Wells Sheet Nº
1/4
File: temp def sketch.srf Date: 05/30/01Scale: 1:125Units:English<ft>
New River Regional Landfill Bioreactor Project
500 CD2
CC3
CD4
CC5
CD6
CC7
CD8
400
450
CH2
CF2
CF3
CG3
CF4
CE5
CG5
CF6
CE7
CG7
CF8
124125126128130132
350
400
CJ2
CH2
CI3
CJ4
CH4
CI5
CJ6
CH6
CI7
CJ8 112114115116118120122124
300CL2
CK3
CM3
CL4
CK5
CM5
CL6
CK7
CL8
CJ8
100102104105106108110
300 350 400 450 500 550
250CN2
CO3
CN4
CO5
CN6
CO7
CN8
Scale: 1:50Units:English<ft>
New River Regional LandfillLocation: Union County, Florida
Monitoring WellInjection Well
Bioreactor Landfill BoundaryAccess Road
Legend Temperature MapInjection Wells B (~40-50 ft deep) Sheet Nº
3/4
File: Temperature.srf Date: 05/30/01
0New River Regional LandfillTemperature Profiles
10
20
30
ndfil
l (ft
)
40
Dep
th fr
om
To
p o
f La
50
60
TP3 TP2
TP4 TP1
7080 85 90 95 100 105 110 115 120 125 130
Temperature (degrees F)
TP4 TP5
Anaerobic vs. Aerobic L dfilliLandfilling
• Flammability• Moisture Balance• Moisture Balance• Process Control• Degradation Pathways• Waste Degradationg• Costs
22 Mixtures that can t b f d
161820 not be formed
ExplosiveRange
121416
ygen
Range
Capable of forming flammable
810
% O
xy
p gmixtures with air (contains too
much methane to be in explosive range)
246 Not capable of
forming flammablemixtures with air
explosive range)
02
0 5 10 15 20 25% Methane
22 Air
161820
121416
ygen
810
% O
xy
Arid Region Landfill
Aerobic Landfill
246 Aerobic Landfill
Anaerobic Landfill02
0 5 10 15 20 25 30 35 40 45 50 55
Anaerobic Landfill
% Methane
Moisture Issues: Anaerobic D itiDecomposition
OHOHC 25106 24 33 COCH
Moisture Issues: Aerobic D itiDecomposition
25106 6OOHC OHCO 22 56
A bi L dfillAerobic Landfill
M i t B lMoisture Balance
Moisture,gpm/acre
Aerobic Anaerobicgpm/acre
Loss/Gain –Biodegradation
0.51 0.24
d iRemoved inExhaust Gas
1.16 0.21
Required Input 0.65 0.45q p
Measure Gas Concentration Gas
Plot data Immediately
Gas in explosive
range.
GasCompositionControl Plot data stop air
injection
range.
Gas
ControlDiagram
outside of explosive
Monitoring
Inspect area for leaks.
YesMonitoring Point in Anaerobic?
O2 >2 % CH4 <40%
Conditions OK
Yes
No
Monitoring Point in
OK
O2 >2 %Decrease Air
Yes
NoAerobic Area Consider
Incr. Flow
No
O2 <2 % CH4 >10%
Measure Temperature
TemperatureT < 140 F
Temperature may be below optimum. Investigate and revise operations as desired. Not a safety hazard.
TemperatureControlDiagram
Optimum conditions. Operate and it h d l d
Diagram
T > 140 FT < 160 F
monitor as scheduled.
T > 160 F T < 170 F
Possible concern. Check gas concentrations. If anaerobic Add leachate If aerobic Reduce air flow rate. Track the rate of temperature increase of this area. If a rate of p1F per day (weekly average) is exceeded, stop air injection and add leachate/water.
Condition of concern Stop air injection Add
T > 170 F
Condition of concern. Stop air injection. Add leachate at permitted amount only, or request that DEP allows more liquid volume injection.
W t D d tiWaste Degradation
• Different pathways– Some compounds are recalcitrant under aerobic
diti d d d d biconditions and degrade under anaerobic conditions and vice versa
• Energy yieldsEnergy yields– Aerobic reactions yield more energy, this can lead
to elevated temperatures under low MCB d t f ti• Byproduct formation– H2S– Methane– Methane
W t St bili tiWaste Stabilization
60 00
70.00
80.00
40.00
50.00
60.00
OD
, g/L
20.00
30.00CO
0.00
10.00
0 10 20 30 40 50
Time, years
Leachate COD Reduction Half-Lives
Scale OperatingRegime
COD Half-Life,Days
Laboratory Anaerobic Wet 26 157Laboratory Anaerobic Wet 26 – 157Laboratory Anaerobic Conventional 150 – 1369Laboratory Semi-aerobic Wet 24Laboratory Semi-aerobic Conventional 26
Pilot Anaerobic Wet 117Pilot Anaerobic Conventional 99Pilot Anaerobic Conventional 99Full Anaerobic Wet 285 – 383Full Anaerobic Conventional 3650
C t ICost Issues
Aerobic– Energy
Anaerobic– Gas gy
Requirements– Loss of methane
collection/treatment– Additional leachate
treatment– Potential GHG emission offset credits
treatment
– Additional moisture requirements
Energy Considerations –A bi L dfillAerobic Landfill
• Blowers– Push air through landfillg– 4.75 x volume of anaerobic gas production– NRRL Aerobic Energy Requirements 12 x
Anaerobic
C l iConclusions• Power requirements are twelve times higher
for an aerobic bioreactor as compared to theanaerobic bioreactoranaerobic bioreactor.
• Aerobic bioreactor moisture requirements are29% higher.g
• Due to the presence of diluent gases inaerobic bioreactor gases, flammable
diti lik l t d l ti l lconditions are unlikely to develop, particularlyif process conditions ensure low oxygenlevels.levels.
C l iConclusions
• The addition of water and air significantlyaccelerations the rate of reduction of organicgmaterial in leachate.
• Oxygen content and internal temperature arecritical control components for aerobic andanaerobic bioreactors.