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.