ELECTRONIC SUPPLEMENTARY MATERIAL
LCA OF WASTE MANAGEMENT SYSTEMS
Life cycle assessment of waste treatment strategy for sewage sludge and food waste in Macau: perspectives on environmental and energy production performance
Sam L. H. Chiu 1 • Irene M. C. Lo 1 • Kok Sin Woon 1 • Dickson Y. S. Yan 2
Received: 29 May 2015 / Accepted: 13 November 2015
© Springer-Verlag Berlin Heidelberg 2015
Responsible editor: Shabbir Gheewala
1 Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
2 Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong, China

Irene M. C. Lo cemclo@ust.hk
1

Appendix A
Table A.1
Food waste characteristics of Hong Kong and Korea
City/country Hong Kong a,b Korea c
Moisture content
Volatile solids/Total solids
79.8 %
90.8 %
79.5 %
95.0 %
Carbon/nitrogen 14.7 15.5 a Since the food waste characteristics of Macau are unavailable from the literature, the food waste characteristics of Hong Kong, a city which has a similar dining style to that of Macau due to their close geographical location (i.e. Hong Kong and Macau are located in the southern part of Guangdong province of China), are used to compare with that of South Korea. b Zhao and Deng 2014 c Han and Shin 2004
2

Table A.2 Summary of data inventory of substrates composition
Parameters
Moisture content
Dry content
Heating value a Zhao and Deng 2014 b IPCC 2006 c Hoffman and Marmsjö 2014
Unit
%
%
MJ/kg dry basis
Food waste a
80
20
21
Sewage sludge
(after dewatering) b
75
25
10
Digestate c
76
24
18.8
3

Table A.3 Summary of data inventory for transportation, sludge dewatering, and food waste pretreatment
Emissions to air
CO
2
CH
4
N
2
O
NO x
CO
SO
2
Respirable suspended particulate (RSP) a
Volatile organic compound (VOCs)
Consumption parameters
Disel
(heavy truck)
Electricity
Electricity a RSP refers to PM
10 in this context b DEFRA, 2011 c DSPA, 2010; d n.a. stands for not applicable e Righi et al. 2013 f Khoo et al. 2010
Unit g/km g/km g/km g/km g/km g/km g/km g/km miles/gallon kWh/tonne of waste kWh/tonne of waste
Transportation
863.4
b
2.24 × 10 -2b
3.25 × 10 -2b
9.53
c
6.20
c
6.09 × 10 -3c
0.7
c
1.66
c
31 b n.a.
d n.a.
Sludge dewatering n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
4.25
e n.a.
Food waste pretreatment n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a.
25 f
4

Table A.4
Summary of data inventory for landfill and compost
Unit Landfill a , b
Emission to air
CO
2
CO kg kg
CH
4
H
2
S
SO
2
NO x
HCL kg
Volatile organic compound (VOCs) kg
N
2
O
NH
3
HF
Respirable suspended particulate
(RSP) d
Materials output
N, P, K content e, f
Compost produced from digestate a Weidema et al. 2013 b Emission per kg of ash c Emission per kg of fertilizer d RSP refers to PM
10 in this context e Razza et al, 2009 f Khoo et al. 2010 g n.a. stands for not applicable kg kg kg kg kg kg kg kg kg tonne/tonne digestate n.a.
g
7.75 × 10 -4
5.42 × 10 -4
8.89 × 10 -7
8.34 × 10 -4
1.46 × 10 -3
1.41 × 10 -5
2.20 × 10 -4
6.09 × 10 -6
1.69 × 10 -5
1.47 × 10 -6
2.51 × 10 n.a. n.a.
-4
N-fertilizer
5.19
1.17 × 10 -2
3.72 × 10 -2
1.45 × 10 -3
2.20 × 10 -2
2.44 × 10 -2
3.58 × 10 -4
2.90 × 10 -3
2.20 × 10 -2
1.07 × 10 -2
6.49 × 10 -5
2.04 × 10 -2
7.95 × 10 -3
Compost a, c
P-fertilizer
1.89
3.94 × 10 -3
1.00 × 10 -2
1.31 × 10 -5
1.48 × 10 -9
7.38 × 10 -3
2.86 × 10 -4
8.10 × 10 -4
2.49 × 10 -4
7.54 × 10 -4
1.40 × 10 -4
2.04 × 10 -2
1.55 × 10 -3
0.45
K-fertilizer
0.83
9.83 × 10 -3
3.95 × 10 -2
1.93 × 10 -3
3.01 × 10 -3
5.90 × 10 -3
7.15 × 10 -5
7.18 × 10 -4
1.96 × 10 -3
4.84 × 10 -3
8.94 × 10 -6
2.04 × 10 -2
9.90 × 10 -3
5

Table A.5
Summary of data inventory for electricity, heat, gasoline and diesel
Emission to air
CO
2
CO
CH
4
H
2
S
SO
2
NOx
HCL
Volatile organic compound (VOCs)
N
2
O
NH
3
HF
Respirable suspended particulate (RSP) f a Chinese Life Cycle Database (2011) b Emission per kWh of electricity c Emission per kg of LPG d Emission per kg of gasoline e Emission per kg of diesel f RSP refers to PM
10 in this context
Unit kg kg kg kg kg kg kg kg kg kg kg kg
Avoided electricity a, b
6.82 × 10 -1
1.20 × 10 -4
1.91 × 10 -3
3.14 × 10 -6
2.36 × 10 -3
1.27 × 10 -5
1.87 × 10 -4
9.05 × 10 -5
1.03 × 10 -5
1.85 × 10 -6
2.34 × 10 -5
1.70 × 10 -6
Avoided heat a, c
3.27 × 10 -1
4.11 × 10 -4
1.96 × 10 -2
4.41 × 10 -6
2.16 × 10 -3
1.52 × 10 -3
2.49 × 10 -5
1.77 × 10 -3
6.75 × 10 -6
9.96 × 10 -6
3.24 × 10 -6
3.80 × 10 -6
Gasoline a, d
4.80 × 10 -1
4.80 × 10 -4
2.20 × 10 -2
5.17 × 10 -6
3.42 × 10 -3
7.19 × 10 -4
3.78 × 10 -5
1.98 × 10 -3
8.67 × 10 -6
1.12 × 10 -5
4.86 × 10 -6
4.33 × 10 -6
Diesel a, e
3.74 × 10 -1
4.35 × 10 -4
2.05 × 10 -2
4.69 × 10 -6
2.65 × 10 -3
6.25 × 10 -4
3.05 × 10 -5
1.85 × 10 -3
7.41 × 10 -6
1.05 × 10 -5
3.94 × 10 -6
4.01 × 10 -6
6

Appendix B
Table B.1 Impact and damage categories results to human health from each scenario for sewage sludge and food waste treatment in part 1
Impact category Unit
Midpoint category
Climate change human health
Photochemical oxidant formation
Particulate matter formation
DALY
DALY
DALY a
Endpoint category
Human health DALY a DALY stands for Disability-adjusted life year b Negative value represents a positive impact to the environment
Scenario EI (SS+FW)
1.40 × 10 -4
7.98 × 10 -9
4.79 × 10 -5
1.87 × 10 -4
Scenario coAD (SS+FW)
-1.48 × 10 -5b
4.94 × 10 -9
3.12 × 10 -5
1.64 × 10 -5
Scenario EI&AD (SS+FW)
1.38 × 10 -4
5.77 × 10 -9
3.69 × 10 -5
1.75 × 10 -4
7

Table B.2 Impact and damage categories results to ecosystems from each scenario for sewage sludge and food waste treatment in part 1
Impact category Unit Scenario EI (SS+FW)
Midpoint category
Climate change ecosystems species-year
Terrestrial acidification species-year
Endpoint category
Ecosystems species-year a Negative value represents a positive impact to the environment
7.89 × 10 -7
-1.12 × 10 -9
7.88 × 10 -7
Scenario coAD (SS+FW)
-8.43 × 10 -8a
-1.43 × 10 -9
-8.57 × 10 -8
Scenario EI&AD (SS+FW)
7.82 × 10 -7
-1.51 × 10 -9
7.80 × 10 -7
8

Table B.3
Energy production performance from each scenario for sewage sludge and food waste treatment in part 1
Energy from process
Electricity (incineration)
Electricity (anaerobic digestion)
Unit
MJ
MJ
Scenario EI (SS+FW)
5.78 × 10 2 (100%) a n.a.
b
Scenario coAD (SS+FW)
2.75 × 10 2 (29%)
3.06 × 10 2 (32%)
Scenario EI&AD (SS+FW)
3.85 × 10 2 (42%)
2.29 × 10 2 (26%)
Heat (anaerobic digestion) MJ n.a. 3.79 × 10 2 (39%) 2.84 × 10 2 (32%)
Total energy produced MJ 5.78 × 10 2 (100%) 9.60 × 10 2 (100%) 8.98 × 10 2 (100%) a Value in bracket is the relative percentage of total energy produced. It is calculated by dividing the respective value of each process with the total energy produced b n.a. stands for not applicable
9

Table B.4 Environmental impact of midpoint category from each scenario for sludge and food waste treatment in part 1
Impact category Unit Scenario EI (SS+FW)
Climate change kg CO
2
eq a 9.98 × 10
Photochemical oxidant formation kg NMVOC b 2.05 × 10 -1
Particulate matter formation kg PM
10
eq c 1.84 × 10 -1
Terrestrial acidification kg SO
2
eq d -1.92 × 10 -1 a kg CO
2
stands for carbon dioxide equivalent in kg b kg NMVOC stands for non-methane volatile organic compound in kg c kg PM
10
eq stands for particulate matter with 10 micrometers or less in diameter equivalent in kg d kg SO
2
eq stands for sulfur dioxide equivalent in kg e Negative value represents a positive impact to the environment
Scenario coAD (SS+FW)
-1.05 × 10 e
1.27 × 10 -1
1.20 × 10 -1
-2.46 × 10 -1
Scenario EI&AD (SS+FW)
9.89 × 10
1.48 × 10 -1
1.42 × 10 -1
-2.61 × 10 -1
10

Table B.5 Impact and damage categories results to human health from each scenario for remaining food waste treatment in part 2
Impact category Unit
Midpoint category
Climate change human health
Photochemical oxidant formation
Particulate matter formation
DALY
DALY
DALY
Endpoint category
Human health DALY a DALY stands for Disability-adjusted life year b Negative value represents a positive impact to the environment a
Scenario EI (FW)
-2.14 × 10 -4b
7.17 × 10 -9
3.86 × 10 -5
-1.75 × 10 -4
Scenario AD (FW)
-2.16 × 10 -4
-2.34 × 10 -9
-8.89 × 10 -6
-2.25 × 10 -4
11

Table B.6 Impact and damage categories results to ecosystems from each scenario for remaining food waste treatment in part 2
Impact category Unit
Midpoint category
Climate change ecosystems
Terrestrial acidification species-year species-year
Endpoint category
Ecosystems species-year a Negative value represents a positive impact to the environment
Scenario EI (FW)
-1.21 × 10 -6a
-2.15 × 10 -9
-1.21 × 10 -6
Scenario AD (FW)
-1.22 × 10 -6
-3.86 × 10 -9
-1.23 × 10 -6
12

Table B.7 Energy production performance from each scenario for remaining food waste treatment in part 2
Energy from process Unit Scenario EI (FW) Scenario AD (FW)
Electricity (incineration)
Electricity (anaerobic digestion)
MJ
MJ
8.40 × 10 2 (100%) a n.a.
b n.a.
9.93 × 10 2 (45%)
Heat (anaerobic digestion) MJ n.a.
1.23 × 10 3 (55%)
Total energy produced MJ 8.40 × 10 2 (100%) 2.22 × 10 3 (100%) a Value in bracket is the relative percentage of total energy produced. It is calculated by dividing the respective value of each process with the total energy produced b n.a. stands for not applicable
13

Table B.8
Environmental impact of midpoint category from each scenario for remaining food waste treatment in part 2
Impact category Unit Scenario EI (FW)
Climate change kg CO
2
eq a -1.53 × 10 2e
Photochemical oxidant formation
Particulate matter formation kg NMVOC b kg PM
10
eq c
1.91 × 10
1.49 × 10
-1
-1
Terrestrial acidification kg SO
2
eq d -3.12 × 10 a kg CO
2
stands for carbon dioxide equivalent in kg b kg NMVOC stands for non-methane volatile organic compound in kg c kg PM
10
eq stands for particulate matter with 10 micrometers or less in diameter equivalent in kg d kg SO
2
eq stands for sulfur dioxide equivalent in kg e Negative value represents a positive impact to the environment
-1
Scenario AD (FW)
-1.54 × 10 2
-6.00 × 10 -2
-3.42 × 10 -2
-6.65 × 10 -1
14

Table B.9 Impact and damage categories results to human health from each scenario for treating all the sewage sludge and food waste generated in Macau in part 3
Impact category
Midpoint category
Unit Scenario EI (all)
Climate change Human Health DALY a
-4.07 × 10 -2b
Photochemical oxidant formation DALY
1.96 × 10 -6
Particulate matter formation DALY
1.08 × 10 -2
Endpoint category
Human health DALY a DALY stands for Disability-adjusted life year
-2.99 × 10 b Negative value represents a positive impact to the environment
-2
Scenario PS (all)
-4.84 × 10
-2.84 × 10
-5.00 × 10
-2
-7
-4
-4.89 × 10 -2
Scenario EI
(all+increased SS)
9.96 × 10 -3
3.65 × 10 -6
2.12 × 10 -2
3.12 × 10 -2
Scenario PS
(all+increased SS)
-3.90 × 10 -2
1.18 × 10 -6
8.41 × 10 -4
-3.06 × 10 -2
15

Table B.10 Impact and damage categories results to ecosystems from each scenario for treating all the sewage sludge and food waste generated in Macau in part 3
Impact category Unit Scenario EI (all)
Midpoint category
Climate change Ecosystems
Terrestrial acidification species-year species-year
-2.31 × 10 -4a
-5.28 × 10 -7
Endpoint category
Ecosystems species-year -2.31× 10 a Negative value represents a positive impact to the environment
-4
Scenario PS (all)
-2.74 × 10 -4
-9.20 × 10 -7
-2.75 × 10 -4
Scenario EI
(all+increased SS)
5.60 × 10 -5
-6.93 × 10 -7
5.35 × 10 -5
Scenario PS
(all+increased SS)
-2.21 × 10 -4
-1.06 × 10 -6
-2.22 × 10 -4
16

Table B.11
Energy production performance from each scenario for treating all the sewage sludge and food waste generated in Macau in part 3
Energy from process Unit Scenario EI (all) Scenario PS (all)
Scenario EI
(all+increased SS)
Scenario PS
(all+increased SS)
Electricity (Incineration)
Electricity (Anaerobic digestion)
MJ
MJ
2.10 × 10 5 (100%) a n.a.
b
1.07 × 10 4 (2%)
2.33 × 10 5 (44%)
3.16 × 10 n.a.
5 (100%) 8.67 × 10 4 (16%)
2.54 × 10 5 (47%)
Heat (Anaerobic digestion) MJ n.a.
2.89 × 10 5 (54%) n.a. 1.96 × 10 5 (37%)
Total energy produced MJ 2.10 × 10 5 (100%) 5.33 × 10 5 (100%) 3.16 × 10 5 (100%) 5.34 × 10 5 (100%) a Value in bracket is the relative percentage of total energy produced. It is calculated by dividing the respective value of each process with the total energy produced b n.a. stands for not applicable
17

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