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Presentation file on Application on Semi-aerobic Landfill. Technology in in Tropical Climate: Lysimeter experiment of Thailand (Created: SWGA Chart Chiemchaisri)
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Application on Semi-aerobic Landfill Technology in in Tropical Climate: Lysimeter experiment of Thailand
Chart Chiemchaisri, Noppharit Sutthasil, Komsilp Wangyao, Kazuto Endo, Masato Yamada
Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, Joint Graduate School of Energy and Environment, King Mongkut’s University of Technology Thonburi, Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, Japan
2
Anaerobic vs Aerobic landfills
Anaerobic (Conventional) Landfill The stabilization of most organic waste in landfill took place under
absence of oxygen. High organic strength leachate was generated during acid phase
followed by long term stabilization in methane phase. High CH4 and CO2 in gas produced during methane phase
Semi-aerobic (Fukuoka Method) and Aerobic (forced aeration) Landfill
Introduction of air yielding aerobic degradation in some or whole part of waste body.
Acceleration of waste stabilization and improvement of leachate qualities
Reducing CH4 emission
3
Objective of this research
To investigate the applicability of semi-aerobic landfill technology in tropical climate
How effective can the air diffuse into the waste body under high moisture condition?
To study the effect of initial waste placement (degree of compaction) and leachate retention on waste stabilization, leachate qualities and gas production in semi-aerobic and anaerobic lysimeters.
To determine methane emission ratio between semi-aerobic and anaerobic conditions
Methane Correction Factor (MCF) for semi-aerobic landfill.
4
Methane Correction Factor (MCF) in IPCC Guidelines
MCF indicates degree of anaerobic condition which creates and emits methane gas from solid waste disposal site.
MCF depends on design and operating condition of the landfills. It can also change with time.
IPCC proposed the following default MCF for different types of landfills
Type of Site Methane Correction Factor (MCF) Default Values
Managed – Anaerobic 1.0
Managed - Semi-Aerobic 0.5
Unmanaged – Deep (>5 m deep) and/or high water Table
0.4
Unmanaged – Shallow (<5 m deep) 0.8
Uncategorised SWDS 0.6
5
Lysimeters
Sm = Semi-aerobic Landfill condition An = Anaerobic Landfill condition
Sm I Sm II An I An II
Pan collector of rainwater (70% of lysimeter area)
6
Lysimeters Condition Sm I Sm II An I An II
Operating Condition Semi-aerobic Semi-aerobic Anaerobic Anaerobic
Waste compaction No compaction
Typical compaction
Typical compaction
Typical compaction
Waste density (kg/m3) 600 750 700 700
Leachate drainage Completed drainage
Completed drainage
0.6 m leachate
head (normal operation)
Fully submerged condition
7
Waste Composition & Characteristics
Food 20%
Paper 19%
Foam 3% Wood
6%
Plastic 16%
Vinyl 17%
Glass 19%
Wet Composition
Food 14% Paper
16%
Foam 3%
Wood 7%
Plastic 18%
Vinyl 15%
Glass 27%
Dry Composition
The waste composition represents average MSW
characteristics of Thailand
• Volatile Solids 79.19 % • Carbon ( C) 43.99 % • Oxygen (O) 4.81 % • Hydrogen (H) 48.41 % • Nitrogen (N) 2.24 % • Phosphorus (P) 0.16 % • Sulfur (S) 0.39 %
8
In-situ monitoring parameters Temperature Probes
Gas Extraction Tube
Moisture Sensors
Data Logging System
Tedlar Bag for GC-analysis
9
Sensors installation on the lysimeters
Daily Cover Lv.4
Lv.3
Lv.2
Lv.1
Initial waste layer height = 2.50 m Cover soil layer = 0.30 m
10
Sampling, Measurement & Analysis Sample frequency
Gas composition (CH4, CO2, O2, N2) Once a week Leachate (pH, EC, BOD, COD, TOC NH4
+, TKN, NO3, TP) Once a week Gas emission (CH4, CO2) Once a month
Close Flux Chamber Method
Estimation of MCF based on methane ratio in landfill gas
MCF = 1 where %CH4/(%CH4 + %CO2) ≥ 0.6 MCF = [%CH4/(%CH4 + %CO2)]/0.6 where CH4/(%CH4 + %CO2) < 0.6
Gas Emission based on close flux measurement F = ρ VΔC/ AΔt
where F = gas flux, g/m2/h ρ = gas density, g/m3 V = volume of chamber, m3 A = area of chamber, m2 ΔC = gas concentration difference (volume fraction) Δt = time, h
11
Variation of rainfall & Settlement Result
Sm I
Sm II
An I
An II
Sett
lem
ent
(cm
.)
Waste Settlement (% From initial height)
Sm I = 35 cm (14 %) Sm II = 30 cm (12 %) An I = 25 cm (10 %) An II = 15 cm ( 6 %)
Cumulative Rainfall = 1,009 L Amount of leachate (% of rainfall)
Sm I = 304 L (30.11%) Sm II = 311 L (30.78%) An I = 301 L (29.82%) An II = 268 L (26.58%)
0
200
400
600
800
1,000
1,200
0 60 120 180 240 300 360 420 480
Cumulat
ive
Rainfa
ll /
Leac
hate
(L)
rainfall
Sm I
Sm II
An I
An II
Time (Days)
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
Time (Days)
Rai
nfal
l / d
ay (L
iter)
12
Leachate characteristics
0
5,000
10,000
15,000
20,000
25,000
0 60 120 180 240 300 360 420 480
TOC(m
g/l)
Sm I
Sm II
An I
An II
Time (Days)
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
0 60 120 180 240 300 360 420 480
BOD (mg/l)
Sm I
Sm II
An I
An II
Time (Days)
4
5
6
7
8
9
0 60 120 180 240 300 360 420 480
pH Sm I
Sm II
An I
An II
Time (Days)
SMI 90% reduction SMI
An I , An II 90% reduction An I , An II
SMII 90% reduction SMII
Time required to reach 90% degree of leachate stabilization - SM I : 2 months - AN I, II : 6 months - SMII: 8 months
13
CH4 content in landfill gas
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
Lv.1 Lv.2 Lv.3 Lv.4
CH4(%
v/v)
Time (Days)
SM I
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
Time (Days)
Rai
nfal
l / d
ay (L
iter)
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
Lv.1 Lv.2 Lv.3 Lv.4
CH4(%
v/v)
Time (Days)
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
CH4 CO2 O2
Gas
Com
posi
tion
(%v/
v)
Time (Days)
SM 2 An
14
Comparison of CH4 content at mid-depth
0
10
20
30
40
50
60
70
0 60 120 180 240 300 360 420 480
Sm I Sm II An I
(%v/
v)
Time (Days)
Lysimeters Condition MCF based on CH4/(CH4+CO2)
Sm I Semi-aerobic (low compaction) 0.52 Sm II Semi-aerobic
(High compaction) 0.82
An I Anaerobic 0.99
15
Gas emission rate & MCF (gas flux based)
Lysimeters Cumulative
CH4 emission (g/m2)
Average emission
(g/m2/kg waste)
Cumulative CO2 emission
(g/m2)
Average emission (g/m2/kg waste)
Relative CH4
emission
Sm I 149 0.20 35,016 47.88 0.5
Sm II 3382 3.83 38,245 43.32 8.6
An I 37,001 43.90 99,783 119.62 98.7
An II 36,480 44.47 95,026 115.84 100
Max ; An II 252 g/m2/d Max ; An II 648.3 g/m2/d
0
50
100
150
200
250
300
0 60 120 180 240 300 360 420 480
Sm I Sm II An I An II
Time (Days)
CH4 Em
ission
(g/
m2 /
d)
0
100
200
300
400
500
600
700
0 30 60 90 120150180210240270300330360390420450480
Sm I Sm II An I An II
Time (Days)
CO2 Em
ission
(g/
m2 /
d)
16
Carbon and Nitrogen balance in the lysimeters
Component Sm I Sm II An I An II
Residual 41.70 46.47 56.40 36.61
Leachate 0.01 0.02 0.03 0.04
Gas (CH4) 0.05 1.39 16.60 17.27
Gas (CO2) 6.39 5.76 15.02 13.09
Unaccounted 51.84 46.36 11.96 32.99
Carbon
Nitrogen Component Sm I Sm II An I An II
Residual 8.30 10.22 14.41 8.90
Leachate 4.67 9.04 10.31 10.82
Gas emission & Unaccounted
87.03 80.74 75.29 80.28
Incl. escape of LFG through leachate pipe (for Sm), internal deposition after leachate stagnant & evaporation
Microbial transformation & emission in gaseous form
17
Conclusion 1. Semi-aerobic landfill could be implemented successfully in
tropical condition provided that the waste cell was prepared without waste compaction. On the other hand, Semi-aerobic landfill with high compaction behaved like anaerobic landfill in terms of leachate stabilization but produced lower methane emission.
2. Both semi-aerobic Landfill with high and low compaction can decrease gas emission from landfill surface more than 90% when compared to anaerobic landfill.
3. Semi-aerobic landfill with low compaction had their organic substances in leachate reduced by 90% after 2 months, much faster than those in semi-aerobic with high compaction and anaerobic conditions (8 and 6 months).
4. Most importantly, waste density is an important factor governing semi-aerobic condition in tropical landfill
18
Future research needs 1. Investigation of optimum aeration rate and operating
condition for inducing natural ventilation into semi-aerobic landfill in tropical climate (wet and dry season).
2. Investigation of possibility to introduce bulking materials or using existing specific waste components in semi-aerobic landfill for promotion of natural ventilation.
3. Investigation of nitrous oxide emission rate and its seasonal variation from semi-aerobic landfill operated in tropical climate.
This research work is carried out under NIES-KMUTT-KU collaboration research laboratory with financial support from
Kasetsart University Research and Development Institute (KURDI)
Acknowledgement
Thank you for your attention