Structure of 6.B WWTD category * in Japan s inventory CH 4 and N 2 O emission sources in 6.B EFs, AD and methodologies

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1 7-10 July 2009, Seoul, Korea GHG Emissions from Wastewater Treatment and Discharge in Japan Hiroyuki Ueda SUR, Japan Cooperative Researcher, GIO, NIES

2 Outline Introduction ti of Japan's emission i estimations from wastewater treatment and discharge (WWTD, 6.B) Structure of 6.B WWTD category * in Japan s inventory CH 4 and N 2 O 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. 2

3 Overview of GHG emissions in Japan CO2 Gg 20,000 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 IP, Solvent 79, % Agriculture 26, % Waste 24,169 18% 1.8% Japan s 2007 inventory * Emissions from the waste sector amounted 24,169 GgCO 2 or 1.8 per cent of total. Emissions from 6.B amounted 90.6% 2,528 GgCO 2 or 10.5 per cent of 2007 Emissions Total : 1,74,011 the waste sector. GgCO2 Emissions from 6.B decreased by 25.9 per cent from 1990 to The key driver was the decrease of emission from gray water 6A Landfill 6B Wastewater 6C Incineration discharged into river, lake and 6D Other 1A Energy recovery (Ref.) sea. Energy 1,244, GHG Emissions in the waste sector * Japan has submitted 2007 data inventory to UNFCCC in April 2009.

4 Structure of Japan s 6.B inventory 5 sub-categories in 6.B Japan divides IPCC 6.B category into 5 original sub-categories according to methodologies for GHG emission estimations. 6.B.1 Industrial 6.B.1 CH 4 and N 2 O emissions from industrial wastewater treatment plant 6.B.2.a CH 4 and dn 2 O emissions i from sewage treatment plant Centralized or on-site treatment 6.B 6.B.2 Domestic/Commercial 6.B.2.b 6.B.2.c CH 4 and N 2 O emissions from Johkasou * and vault toilet CH 4 and N 2 O emissions from night soil treatment plant 6.B.2.d CH 4 and N 2 O emissions from gray water ** discharged into river, lake and sea Discharge without treatment 6.B. Other Japan s original sub-category IPCC categories No activity in Japan * Johkasou : Japan s original on-site domestic wastewater treatment system **Gray water: Miscellaneous domestic wastewater except night soil 4

5 Emissions of Japan s 6.B inventory GgC CO2 4,000,500,000 2, ,000 1,500 1, B1 Industrial 6B2a Sewage 6B2b Johkasou 6B2c Night soil 6B2d Gray water GHG Emissions from each sub-category in the waste sector 140,000 Continuous o decrease ease since 1990 In 1990, the largest emission source in 6.B was 6.B.2.d, however, decreased by 785 GgCO 2 or 56.0 per cent between 1990 and 2006 *. This decline has contributed to the decrease ease of 6.B total emissions s (882 GgCO 2 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 pers son 120, ,000 80,000 60,000 40,000 Sewage Johkasou Vault toilet Other 20, Domestic wastewater treatment population in Japan *In 2009 inventory, 2007 data is in preparation and 2006 data was substituted. 5

6 Typical emission sources in 6.B Domestic / industrial wastewater Collected Uncollected Green cells : GHG emission sources in Japan Untreated Treated Treated on-site Untreated River, lake and sea Stagnant sewer Sewered to plant River, lake and sea To ground Wetland Anaerobic treatment Aerobic treatment Bold frame : Potential CH 4 or N 2 O emission sources in 6.B Dotted frame : Emission sources in other categories / sectors Lagoon Reactor Sludge Wastewater treatment process Concentration Sludge treatment process Anaerobic digestion Aerobic/other treatment Sea Conditioning and dehydration, drying Source : IPCC 1996GL, GPG, 2006GL and Japan s NIR Land disposal Composting Landfill Incineration Construction Agriculture materials (6.D) (6.A) (6.C, 1.A) (4.D) Other utilization 6

7 Industrial WWT system in Japan On-site treatment t t Every industries that produce polluted wastewater are required to treat the polluted wastewater by on-site plants according to the Water Pollution Control Law. Wastewater from livestock industry is considered in the agriculture sector, not in 6.B, according to IPCC GL. Industrial wastewater producers Manufacturing industry (high concentration) Emission sources in 6.B.1 Manufacturing industry (low and other) 6.B.1 CH 4 and N 2 O emissions from industrial wastewater treatment plant Commercial trade, Other trade Bold line : Major CH 4 or N 2 O producing stream Livestock industry Agriculture sector 7

8 Domestic WWT system in Japan Domestic wastewater treatment population p in Japan, 2006FY Sewage Collected system 8,742 8,742 Centralized and on-site treatment 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. Total population 127,781 Bold line : Major CH 4 or N 2 O producing stream Emission sources in 6.B.2 6.B.2.a CH 4 and N 2 O emissions from sewage treatment plant Johkasou 0,84 6.B.2.b CH 4 and N 2 O emissions from Johkasou and vault toilet Uncollected 44,09 Vault toilet 12,98 Other 222 (Thousand persons) 6.B.2.c 6.B.2.d CH 4 and N 2 O emissions from night soil treatment plant CH 4 and N 2 O emissions from gray water discharged into river, lake and sea 8

9 GHG sources in Industrial wastewater treatment system Green cells : GHG emission sources in 6.B Major organic or nitrogenous industrial wastewater producers Pulp and paper Organic chemicals, plastics Black liquor On-site treatment plant Activated sludge * Biochemical * Energy for boiler 6.B.1 (1.A) CH 4 Utilization Recovered from anaerobic reactors Food, meat and poultry processing Beverage, tobacco, feed Textile and apparel Leather and skins Industrial wastewater t Other advanced * Sand filtering Oil separation Thickener Activated carbon *Wastewater treated at these types of plants are considered as emission sources. Sludge Oil refinery, coking Rubber Ozonization Other Incineration (6.C, 1.A) Sewage treatment Other industries ** plant 6.B.2.a **Other industries are not considered as an emission source. Landfill (6.A) Other Dotted frame : GHG sources in other categories / sectors 9

10 GHG sources in Sewage treatment system Utilization / flaring Green cells : GHG emission sources in 6.B CH 4 Recovered from anaerobic digestion Sewage treatment plant 6.B.2.a Domestic wastewater Sewer lines Water treatment Process (aerobic, anaerobic) Sludge treatment Process (Concentration, etc) Sludge Incineration (6.C, 1.A) Industrial wastewater Sewer lines Composting (6.D) Night soil from vault toilet Transport Landfill (6.A) Sludge from Johkasou Transport Agriculture (4.D) Sludge from night soil treatment plant Transport 6.B.2.d Sea * Dotted frame : GHG sources in other categories / sectors Other *Terminated since

11 GHG sources in Johkasou system 6.B.2.b Green cells : GHG emission sources in 6.B Community Plant * (Night soil & gray water) Sludge Night soil Gray water Gappei-Johkasou ** (Night soil & gray water) 6.B.2.b Sewage treatment plant Night soil treatment plant 6.B.2.a 6B2 6.B.2.c Tandoku-Johkasou *** (Night soil only) Sea 6.B.2.d 6.B.2.b Other Untreated Rivers, lakes, estuaries, sea 6B2d 6.B.2.d * Community Plant : collectively treats domestic wastewater and have similar features to a large-scale Gappei-Johkasou. ** Gappei-Johkasou : is designed d for both night soil and gray water treatment t t at household. h ***Tandoku-Johkasou : is an old-type Johkasou and treats only night soil. Newly installation has been prohibited since Dotted frame : GHG sources in other categories / sectors 11

12 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 Night soil Gray water Vault toilet (Storage) Rivers, lakes, estuaries, sea Anaerobic treatment Denitrification treatment High-load denitrification Membrane filtering Sludge Incineration (6.C, 1.A) 6.B.2.d Transport Other treatments Composting (6.D) Transport Landfill (6.A) Sludge from Johkasou Other Night soil Manure Agriculture (4.D) Sewage treatment plant 6.B.2.a Agriculture Sewage treatment plant (4.D) Gray water Rivers, lakes, estuaries, sea 6.B.2.d 6.B.2.a 6.B.2.d Sea Dotted frame : GHG sources in other categories / sectors Other 12

13 Equation for CH 4 estimation q 4 Japan s country specific equation for CH 4 is as follows. Japan s country specific equation for 6.B.2.a, 6.B.2.b and 6.B.2.c uses m or person as AD, according to domestic research. Basic theory is almost the same with IPCC equation *, that t uses kg of organic matter (BOD or COD) as AD. *Equation 5.5 in GPG and 6.1, 6.4 in 2006GL Recovered CH 4 from anaerobic reactor or digestion are not used for CH 4 because country specific EF is not CH 4 production but CH 4 emission. CH4 Emission = EF AD EF : CH4 emissions per m (kgch 4/m ) or person (kgch4/person) AD : treated wastewater (m ) or person (person) Summary for method, AD and EF of CH 4 estimation in Japan Sub-category Method AD EF 6.B.1 Industrial wastewater treatment plant D kg BOD CS 6.B.2.a Sewage treatment plant CS m CS 6.B.2.b Johkasou and vault toilet CS person CS 6.B.2.c Night soil treatment plant CS m CS 6.B.2.d Gray water discharged into river, lake and sea D kg BOD D CS: Country Specific D : Default value or method of IPCC GL, GPG. 1

14 Equation for N 2 2O estimation Japan s country specific equation for N 2 O is as follows. Japan s country specific equation for 6.B.2.a and 6.B.2.b uses m or person as AD, according to domestic research. Basic theory is almost the same with IPCC equation *, that t uses kg of nitrogen or person as AD. N2 O Emission = EF AD EF :N2O emissions per m AD : treated wastewater (m (kgn2o/m ) or person (kgn2o/person) ) or person (person) *Equation 6.7, 6.9 in 2006GL Summary for method, AD and EF of N 2 O estimation in Japan Sub-category Method AD EF 6.B.1 Industrial wastewater treatment plant D kg N CS 6.B.2.a Sewage treatment plant CS m CS 6.B.2.b Johkasou and vault toilet CS person CS 6B2 6.B.2.c Night soil treatment plant D kg N CS 6.B.2.d Gray water discharged into river, lake and sea D kg N D CS: Country Specific D : Default value or method of IPCC GL, GPG. 14

15 6.B.1 GHG from Industrial wastewater treatment plant Methodology, EFs and AD 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. As country specific EF for CH 4 or N 2 O from industrial wastewater treatment are unavailable, EFs of domestic wastewater are substituted. As the concentration of industrial wastewater differs from domestic, EFs (kgch 4 /m, kgn 2 O/m ) are converted to (kgch 4 /kgbod, kgn 2 O/kgN). Statistical data of the volume (m ) of industrial wastewater treated with activated sludge or anaerobically, multiplied by BOD or nitrogen concentration of each industry, are used as AD. Emission = EF AD EF : CH4 or N2 O emissions io per kg or BOD (kgch 4 /kgbod) or N ( kgn 2 O/kgN) 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 CH 4 D kg BOD CS N 2 O D kg N CS 15

16 6.B.2.a GHG from Sewage treatment plant Methodology, EFs and AD IPCC GL indicates aerobic system may not be CH 4 sources. However, Japan has detected CH 4 production and regarded it as the emission source as well as anaerobic (AO, A2O and A2) system. EF is the mean value of measured EFs at 14 plants (CH 4 ) and 8 plants (N 2 O). Both wastewater and sludge treatment process are considered. Statistical data of the volume (m ) of all wastewater treated at sewage treatment plants except primary treatment are used as AD. Emission = EF AD EF : CH 4 AD : Volume of or N O emissions per m 2 (kgch /m, kgn O/m ) 4 all wastewater treated at sewage treatment plants (m 2 ) Summary for method, AD and EF of sewage treatment plant GHG Method AD EF CH 4 CS m CS N 2 O CS m CS 16

17 6.B.2.b GHG from Johkasou and vault toilet Methodology, EFs and AD Emissions are calculated by 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 Tandoku- Johkasou, therefore, e e, emission from vault toilet is calculated cu a by the same 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. ( EFι ADι) Emission = EFι : CH4 or N2O emissions per person at Johkasou ι (kgch4/person, kgn2o/person) ADι : Treatment population at Johkasou ι (person) Summary for method, AD and EF of Johkasou and vault toilet GHG Method AD EF CH 4 CS m CS N 2 O CS m CS 17

18 6.B.2.c GHG from Night soil treatment plant Methodology, EFs and AD Emissions are calculated by every types of treatment methods in the night soil treatment plant *. CH 4 EF for anaerobic, denitrification ifi ti and high-load h denitrification ifi ti are set from domestic research results. EF for the rest are substituted by the average of denitrification and high-load denitrification. N 2 OEFforhigh-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 soil treated at plants (CH 4 4) and the amount of nitrogen included in the night soil (N 2 O) are used as AD. EF ι : CH ( EFι ADι) Emission = 4 emissions per m ADι : Volume of all wastewater (m Summary for method, AD and EF of night soil treatment plant (kgch /m ) and N O per nitrogen in human waste (kgn O/kgN) 4 2 ) and nitrogen in human waste (kgn) 2 GHG Method AD EF CH 4 CS m CS N 2 O D kg N CS * Treatment t of aerobic, anaerobic, denitrification, ifi ti high-load h denitrification, membrane filtering and other. **EF of recent plant decreased because of progress of structure standard and maintenance technology. 18

19 6.B.2.d GHG from Gray water discharged into river, lake and sea Methodology, EFs and AD 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. Gray water from household which use Tandoku-Johkasou, vault toilet or self-treatment and sludge from Johkasou, sewage treatment plant and night soil treatment e plant pa are aeregarded egadedasgas GHG Gpoduc producing gactivity. Statistical data of the volume (m ) of discharged gray water and sludge, multiplied by BOD or nitrogen concentration of each activity are used as AD. Emission = EF ( AD ) ι EF : CH4 or N2O emissions per kg or BOD (kgch4/kgbod) or N ( kgn2o/kgn), default value ADιι :BOD or N in gray water and sludge discharged without treatment (kgbod, kgn) Summary for method, AD and EF of gray water and sludge discharged into river, lake and sea GHG Method AD EF CH 4 D kg BOD D N 2 O D kg N D 19

20 Sharing experience 1: Importance of early and planned preparation Category 6.B has some specific problems compared with other categories in the waste sector. Few or no statistics are available for activity data. Country specific methodologies and EFs are not sufficiently developed. The extent of emission sources are diverse and 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 and well-planned l preparation is important. 20

21 Sharing experience 2 : Importance of prioritization of targets Human, institutional and financial i resources are often limited. However, many things are to be resolved for accurate 6.B inventory. Pi Prioritization iti of ft targets t is important. 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 Make detailed d and transparent t documents Apply quality assurance and quality control (QA/QC) Estimate uncertainty Other 21

22 Sharing experience : Procedure for improving 6.B inventory One of the way to improve 6.B inventory is as follows. 1. Understand all emission sources in 6.B (slide 6) 2. List all industrial and domestic WWT system (slide 7 and 8). List all emission sources in each system (slide 9 to 12) 4. Consider methodologies, EFs and AD (slide 1 to 19) Collect available statistics for AD Collect candidates for EF (CS, default, EFDB and other countries) Decide methodology (Tier 1, 2 or ) according to AD and EF 5. List problems to be improved in the future List problems on EF, AD, methodologies in terms of transparency, comparability, completeness, consistency and accuracy Share the experience and exchange information (in the future WGIA) 22

23 Thank you for your attention. Hiroyuki Ueda ( 植田洋行 ) Suuri-keikaku (SUR), Japan ( 株式会社数理計画 ) Cooperative researcher, Greenhouse gas inventory office of Japan, NIES ueda_hiroyuki@sur.co.jp 2