GHG Emissions from Wastewater Treatment and Discharge in Japan

7th Workshop on Greenhouse Gas Inventories in Asia 7-10 July 2009, Seoul, Korea

GHG Emissions from Wastewater Treatment and Discharge in Japan Hiroyuki Ueda SUR, Japan Cooperative Researcher, GIO, NIES

7th Workshop on Greenhouse Gas Inventories in Asia

Outline

I t d ti Introduction off Japan's J ' emission i i estimations ti ti from f wastewater treatment and discharge (WWTD, 6.B) Structure of 6.B 6 B WWTD category* in Japan’s Japan s inventory CH4 and N2O emission sources in 6.B EFs, AD and methodologies

Sharing experience and information exchange Early and well-planned preparation Prioritization of targets Process for improvement

* In the annual inventory, Japan reports GHG emissions as “6.B wastewater handling” according to FCCC/CP/2002/8. However, this presentation uses more appropriate definition of “wastewater treatment and discharge (WWTD)” from 2006GL instead.

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Overview of GHG emissions in Japan p IP, Solvent 79,047 , 5.8%

Agriculture 26,546 1.9%

Waste 24,169 1 8% 1.8%

* J Japan’s ’ 2007 inventory i t

Emissions from the waste sector amounted 24,169 GgCO g 2 or 1.8 per cent of total. Emissions from 6.B amounted , GgCO g 2 or 10.5 p per cent of 2,528 the waste sector. Emissions from 6.B decreased by 25.9 p per cent from 1990 to 2007. The key driver was the decrease of emission from gray water discharged g into river,, lake and sea.

Energy 1,244,493 90.6%

2007 Emissions Total : 1,374,011 GgCO 2

20,000 18,000 16,000 14,000 6A Landfill 6B Wastewater

GgCO2

12,000

6C Incineration 6D Other 1A Energy recovery (Ref.)

10,000 8,000 6,000 4,000 2,000 0 1990

1992

1994

1996

1998

2000

2002

2004

GHG Emissions in the waste sector

2006

* Japan has submitted 2007 data inventory to UNFCCC in April 2009.

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Structure of Japan’s p 6.B inventory y

5 subsub b-categories t i in i 6.B 6B

Japan divides IPCC 6.B category into 5 original sub-categories according g to methodologies g for GHG emission estimations. 6.B.1 Industrial

6.B

6.B.2 Domestic/Commercial

6.B.3 Other IPCC categories

6.B.1

CH4 and N2O emissions from industrial wastewater treatment plant

6.B.2.a

CH4 and d N2O emissions i i from f sewage treatment plant

6.B.2.b

CH4 and N2O emissions from Johkasou* and vault toilet

6.B.2.c

CH4 and N2O emissions from night soil treatment plant

6.B.2.d

CH4 and N2O emissions from gray water** discharged into river, lake and sea

Centralized or on-site treatment

Discharge without treatment

Japan’s original sub-category sub category No activity in Japan

* Johkasou : Japan’s original on-site domestic wastewater treatment system **Gray water: Miscellaneous domestic wastewater except night soil

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Emissions of Japan’s p 6.B inventory y 6B1 Industrial 6B2a Sewage 6B2b Johkasou 6B2c Night soil 6B2d Gray water

4,000 3,500 3,000

Contin o s decrease Continuous dec ease since 1990

GgC CO2

2,500 2 000 2,000 1,500 1,000

500 0 1990

1992

1994

1996

1998

2000

2002

2004

2006

GHG Emissions from each sub-category in the waste sector

140,000

In 1990, the largest emission source in 6.B was 6.B.2.d, however, decreased by 785 GgCO2 or 56.0 56 0 per cent between 1990 and 2006*. This decline has contributed to the decrease dec ease o of 6 6.B total o a e emissions ss o s (882 (88 GgCO2 from 1990 to 2006). The key driver for the decline of 6.B.2.d was the progress of conversion of vault toilet to sewage system.

thousand persson

120,000 Sewage Johkasou Vault toilet Other

100,000 80,000 60,000 40,000 20,000

*In 2009 inventory, 2007 data is in preparation and 2006 data was substituted.

0 1990

1992

1994

1996

1998

2000

2002

2004

2006

Domestic wastewater treatment population in Japan

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Typical yp emission sources in 6.B Domestic / industrial wastewater

Collected

Untreated

Green cells : GHG emission sources in Japan

Uncollected

Treated

River, lake and sea

Stagnant sewer

Sewered to plant

Wetland

A Anaerobic bi treatment

A Aerobic bi treatment

Treated on-site

Untreated

River, lake and sea

Bold frame : Potential CH4 or N2O emission sources in 6.B 6B Dotted frame : Emission sources in other categories / sectors Sludge

Lagoon

Wastewater treatment process

Reactor

Sludge treatment process

Concentration

Anaerobic digestion

Land disposal

Aerobic/other treatment

Conditioning and dehydration, drying

Sea

To ground

Composting

Landfill

Incineration

(6.D)

(6.A)

(6.C, 1.A)

Source : IPCC 1996GL, GPG, 2006GL and Japan’s NIR

Construction materials

Agriculture (4.D)

Other utilization

6


Industrial WWT system y in Japan p

O -site OnOn it treatment t t t Every industries that produce polluted wastewater are required to treat the polluted wastewater by on-site plants according g to the Water Pollution Control Law. Wastewater from livestock industry is considered in the g sector,, not in 6.B,, according g to IPCC GL. agriculture

Industrial wastewater producers Manufacturing industry (high concentration) Emission sources in 6.B.1 Manufacturing industry (low and other)

Commercial trade, Other trade

Livestock industry

6.B.1

CH4 and N2O emissions from industrial wastewater treatment plant

Bold line : Major CH4 or N2O producing stream

Agriculture sector

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Domestic WWT system y in Japan p Domestic wastewater treatment population p p in Japan, p , 2006FY

C t li d and Centralized d onon-site it treatment t t t All night soil are treated at centralized or on-site plants. Some gray water is discharged into river, lake and sea without treatments.

Collected 83,742

Sewage system 8 83,742

Total population 127,781 ,

Bold line : Major CH4 or N2O producing stream

Emission sources in 6.B.2

Johkasou 30,834

Uncollected 44,039

Vault toilet 12,983 Other 222

(Thousand persons)

6.B.2.a

CH4 and N2O emissions from sewage treatment plant

6.B.2.b

CH4 and N2O emissions from Johkasou and vault toilet

6.B.2.c

CH4 and N2O emissions from night soil treatment plant

6.B.2.d

CH4 and N2O emissions from gray water discharged into river, river lake and sea

8


GHG sources in Industrial wastewater treatment system Green cells : GHG emission sources in 6.B Energy for boiler

Black liquor Major organic or nitrogenous industrial wastewater producers

On-site treatment plant Activated

Biochemical*

Food, meat and poultry processing

Other advanced*

Beverage, tobacco, feed

Sand filtering

Industrial wastewater t t

CH4

sludge*

Organic chemicals, plastics

Recovered from anaerobic reactors *Wastewater treated at these types of plants are considered as emission sources.

Oil separation p Thickener

Leather and skins

Activated carbon

Oil refinery refinery, coking

Ozonization Other

Rubber

Other industries**

Utilization 6.B.1

Pulp and paper

Textile and apparel

(1.A)

Sludge

Incineration

Landfill

Sewage treatment plant 6.B.2.a

**Other industries are not considered as an emission source.

(6.C, 1.A)

(6.A)

Other

Dotted frame : GHG sources in other categories / sectors

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GHG sources in Sewage treatment system Utilization / flaring

CH4

Recovered from anaerobic digestion 6.B.2.a

Sewage treatment plant

Domestic wastewater

Sewer lines

Industrial wastewater Night soil from vault toilet Sludge from Johkasou Sludge from night soil treatment plant

Water treatment Process (aerobic, anaerobic)

Green cells : GHG emission sources in 6.B

Sludge treatment Process (Concentration, etc)

Sludge

Incineration

(6.C, 1.A)

C Composting i

(6 ) (6.D)

Landfill

(6.A)

Agriculture

(4.D)

Sewer lines

Transport

Transport Sea* T Transport t

6.B.2.d d Other


*Terminated since 2004

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GHG sources in Johkasou system y Green cells : GHG emission sources in 6.B 6.B.2.b

Community Plant*

Sludge

(Night soil & gray water)

6.B.2.b

Night soil

Gappei-Johkasou**

(Night soil & gray water)

Gray water

Sewage treatment plant Night soil treatment plant Sea

Tandoku-Johkasou***

6.B.2.a

6B2 6.B.2.c

6.B.2.d

(Night soil only)

6.B.2.b

Untreated

Rivers, lakes, estuaries, sea

Other

6B2d 6.B.2.d

* Community Plant : collectively treats domestic wastewater and have similar features to a large-scale Gappei-Johkasou. ** Gappei-Johkasou G i J hk : is i designed d i d ffor b both th night i ht soil il and d gray water t treatment t t t att household. h h ld ***Tandoku-Johkasou : is an old-type Johkasou and treats only night soil. Newly installation has been prohibited since 2001.


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GHG sources in

Vault toilet and other system Green cells : GHG emission sources in 6.B

6.B.2.b

Night soil treatment plant

6.B.2.c

Aerobic treatment Vault toilet (Storage)

Night soil

Anaerobic treatment

High-load g denitrification

Rivers, lakes, Ri l k estuaries, sea

Membrane filtering

Transport

6.B.2.d

Sludge

Denitrification treatment

Gray water

Other treatments

Transport

Incineration

(6.C, 1.A)

Composting

(6.D)

Landfill

(6.A)

Agriculture

(4.D)

Sludge from Johkasou

Other Night soil Gray water

Manure

Agriculture Rivers, lakes, estuaries, sea

(4.D)

6.B.2.d

Sewage treatment plant

6.B.2.a

6.B.2.a

6.B.2.d


Sewage treatment plant Sea

Other

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Equation q for CH4 estimation

Japan’s co country nt specific eq equation ation fo for CH4 is as follows. follo s

Japan’s country specific equation for 6.B.2.a, 6.B.2.b and 6.B.2.c uses m3 or person as AD, according to domestic research. B i theory Basic th iis almost l t the th same with ith IPCC equation ti *, that th t uses kg k off *Equation 5.5 in GPG and 6.1, 6.4 in 2006GL organic matter (BOD or COD) as AD. Recovered CH4 from anaerobic reactor or digestion are not used for CH4 because country specific EF is not “CH CH4 production production” but “CH CH4 emission emission”.

CH4 Emission = EF • AD EF : CH4 emissions per m3 (kgCH4/m3 ) or person (kgCH4/person) AD : treated wastewater (m3 ) or person (person) Summary for method, AD and EF of CH4 estimation in Japan

Sub-category

Method

AD

EF

D

kg BOD

CS

6.B.2.a Sewage treatment plant

CS

m3

CS

6.B.2.b Johkasou and vault toilet

CS

person

CS

6.B.2.c Night soil treatment plant

CS

m3

CS

6.B.2.d Gray water discharged into river, lake and sea

D

kg BOD

D

6.B.1

Industrial wastewater treatment plant

CS: Country Specific D : Default value or method of IPCC GL,, GPG.

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Equation q for N2O estimation

Japan’s co country nt specific eq equation ation fo for N2O is as follows. follo s

Japan’s country specific equation for 6.B.2.a and 6.B.2.b uses m3 or person as AD, according to domestic research. B i theory Basic th iis almost l t the th same with ith IPCC equation ti *, that th t uses kg k off *Equation 6.7, 6.9 in 2006GL nitrogen or person as AD.

N2O Emission = EF • AD EF : N2O emissions per m3 (kgN2O/m3 ) or person (kgN2O/person) AD : treated wastewater (m3 ) or person (person)

Summary for method, AD and EF of N2O estimation in Japan

Sub-category

Method

AD

EF

D

kg N

CS

6.B.2.a Sewage treatment plant

CS

m3

CS

6.B.2.b Johkasou and vault toilet

CS

person

CS

Ni h soil Night il treatment plant l 6B2 6.B.2.c

D

k N kg

CS

6.B.2.d Gray water discharged into river, lake and sea

D

kg N

D

6.B.1


CS: Country Specific D : Default value or method of IPCC GL, GPG.

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6.B.1 GHG from


Methodolog EFs and AD Methodology,

Emissions from activated sludge or anaerobic treatment of industrial wastewater that contain high concentration of organic matter or nitrogen are estimated due to domestic research. research As country specific EF for CH4 or N2O from industrial wastewater treatment are unavailable, EFs of domestic wastewater are substituted. As the concentration of industrial wastewater differs from domestic, domestic EFs 3 3 (kgCH4/m , kgN2O/m ) are converted to (kgCH4/kgBOD, kgN2O/kgN). Statistical data of the volume (m3) of industrial wastewater treated with activated sludge g or anaerobically, y, multiplied p by y BOD or nitrogen g concentration of each industry, are used as AD.

Emission = EF • AD EF : CH4 or o N2 O emissions e i io per e kg k or o BOD (kgCH (k CH4/kgBOD) /k BOD) or o N ( kgN k N2 O/kgN) O/k N) AD : BOD or N in the wastewater treated with activated sludge or anaerobically (kgBOD, kgN) Summary for method, AD and EF of industrial wastewater treatment plant

GHG

Method

AD

EF

CH4

D

kg BOD

CS

N2O

D

kg N

CS

15


6.B.2.a GHG from Sewage treatment plant


IPCC GL indicates aerobic system may not be CH4 sources. However, Japan has detected CH4 production and regarded it as the emission source as well as anaerobic (AO, (AO A2O and A2) system. system EF is the mean value of measured EFs at 14 plants (CH4) and 8 plants (N2O). Both wastewater and sludge treatment process are considered. Statistical data of the volume (m3) of all wastewater treated at sewage treatment plants except primary treatment are used as AD.

Emission ss o = EF • AD EF : CH4 or N2 O emissions per m3 (kgCH4/m3 , kgN2 O/m3 ) AD : Volume of all wastewater treated at sewage treatment plants (m3 ) Summary for method, method AD and EF of sewage treatment plant

GHG

Method

AD

EF

CH4

CS

m3

CS

N2O

CS

m3

CS

16


6.B.2.b GHG from Johkasou and vault toilet


Emissions are calculated by 3 types of Johkasou including Community Plant, Gappei-Johkasou and Tandoku-Johkasou. EFs are the mean value of measured EFs at each Johkasou. Vault toilet is not Johkasou but storage tank of night soil. Its GHG producing process is unknown but seems to be similar with TandokuJohkasou o asou, therefore, e e o e, emission e ss o from o vault au toilet o e is s calculated ca cu a ed by y the e same sa e method and EF of Tandoku-Johkasou. Statistical data of the treatment population (person) of each types of Johkasou and vault toilet are used as AD.

Emission = ∑ (EFι • ADι ) EFι : CH4 or N2 O emissions per person at Johkasou ι (kgCH4/person, kgN2 O/person) ADι : Treatment population at Johkasou ι (person) Summary for method, AD and EF of Johkasou and vault toilet

GHG

Method

AD

EF

CH4

CS

m3

CS

N2O

CS

m3

CS

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6.B.2.c GHG from Night soil treatment plant


Emissions are calculated by every types of treatment methods in the night soil treatment plant*. CH4 EF for f anaerobic, bi denitrification d it ifi ti and d high-load hi h l d d denitrification it ifi ti are sett from domestic research results. EF for the rest are substituted by the average of denitrification and high-load denitrification. N2O EF for high-load high load denitrification and membrane filtering are set from domestic research results**. EF for the rest are substituted by the EF of high-load denitrification because of lack of research output. Statistical data of the volume of night g soil treated at p plants ((CH4) and the amount of nitrogen included in the night soil (N2O) are used as AD.

Emission = ∑ (EFι • ADι ) EFι : CH4 emissions per m3 (kgCH4/m3 ) and N2 O per nitrogen in human waste (kgN2 O/kgN) ADι : Volume of all wastewater (m3 ) and nitrogen in human waste (kgN) Summary for method, AD and EF of night soil treatment plant

GHG

Method

AD

EF

CH4

CS

m3

CS

N2O

D

kg N

CS

* Treatment T t t off aerobic, bi anaerobic, bi denitrification, d it ifi ti high-load hi h l d denitrification, membrane filtering and other. **EF of recent plant decreased because of progress of structure standard and maintenance technology.

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6.B.2.d GHG from

Gray water discharged into river, lake and sea


Emissions from gray water and sludge discharged into river, lake and sea without treatment are estimated by IPCC default method* and EFs, because country specific method and EF is unavailable. unavailable Gray water from household which use Tandoku-Johkasou, vault toilet or self-treatment and sludge from Johkasou, sewage treatment plant and night g so soil treatment ea e plant p a are a e regarded ega ded as GHG G G producing p oduc g ac activity. y Statistical data of the volume (m3) of discharged gray water and sludge, multiplied by BOD or nitrogen concentration of each activity are used as AD.

Emission = EF • ∑ (ADι ) EF : CH4 or N2 O emissions per kg or BOD (kgCH4/kgBOD) or N ( kgN2 O/kgN), default value ADι : BOD or N in gray water and sludge discharged without treatment (kgBOD, (kgBOD kgN) Summary for method, AD and EF of gray water and sludge discharged into river, lake and sea

GHG

Method

AD

EF

CH4

D

kg BOD

D

N2O

D

kg N

D

19


Sharing g experience p 1:

Importance of early and planned preparation

C t Category 6 B has 6.B h some specific ifi problems bl compared d with other categories in the waste sector.

Few or no statistics are available for activity data. data Country specific methodologies and EFs are not sufficiently developed. The extent of emission sources are diverse and obscure. obscure Condition and mechanism of GHG production are not sufficiently cleared. The amount of emissions in 6.B are likely to be much smaller than other categories in the waste sector.

As it takes a long time to make accurate 6.B inventory, early l and d wellwell ll-planned l d preparation i i important. is i 20



Importance of prioritization of targets

H Human, iinstitutional tit ti l and d financial fi i l resources are often limited. However, many things are to be resolved for accurate 6.B 6 B inventory. inventory

P i iti ti Prioritization off targets t t is i important. i t t

Estimate major (or all) GHG emissions Estimate GHG emissions in both urban and rural areas Estimate GHG emissions back to the past year Improve accuracy of EFs, AD and methodologies M k detailed Make d t il d and d transparent t t documents d t Apply quality assurance and quality control (QA/QC) Estimate uncertainty Other

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Procedure for improving 6.B inventory

O One off th the way to t improve i 6.B 6 B inventory i t is i as follows. f ll 1. 2. 3. 4.

Understand all emission sources in 6.B (slide 6) List all industrial and domestic WWT system (slide 7 and 8) List all emission sources in each system (slide 9 to 12) Consider methodologies, EFs and AD (slide 13 to 19)

5.

Collect available statistics for AD Collect candidates for EF (CS, default, EFDB and other countries) Decide methodology (Tier 1, 2 or 3) according to AD and EF

Li t problems List bl to t be b improved i d in i the th future f t

List problems on EF, AD, methodologies in terms of transparency, comparability, completeness, consistency and accuracy Sh Share th the experience i and d exchange h information i f ti (in (i the th future f t WGIA)

22


Thank you for your attention.

Hiroyuki Ueda

（植田洋行）

Suuri-keikaku (SUR), Japan （株式会社数理計画） SuuriCooperative researcher, Greenhouse gas inventory office of Japan, NIES [email protected]

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