Circular Economy

Circular Economy (CircularEconomy) includes three subsectors (* indicates non-emission subsector):

• Liquid Waste* (WALI)

• Solid Waste (WASO)

• Wastewater Treatment (TRWW)

Circular Economy is used to account for the production of, and emissions from, liquid and solid waste from industrial and domestic sources. Circular Economy includes three subsectors: liquid waste (used only to account for the production of liquid waste), solid waste, and wastewater treatment. These three sectors are derived from Volume 5 of the IPCC guidance for national greenhouse gas inventories and include detailed estimates of of emissions from wastewater treatment and management pathways, solid waste treatment pathways, including a first order decay model of landfilled waste, and recycling, which then is passed to the industrial production model to estimate changes to production of virgin materials. Waste generation is primarily driven by per person generation factors, which are responsive to changes in GDP, GDP/capita, and population and other sectors, including livestock manure management and supply chain loss in agriculture.

Liquid Waste (WALI)

Liquid waste includes…

Categories

Categories associated with Liquid Waste are identified by the $CAT-WASTE-LIQUID$ variable schema element and shown in the category attribute table shown below.

Liquid Waste categories ($CAT-WASTE-LIQUID$ attribute table)

Category Name	$CAT-WASTE-LIQUID$	Description	Data Source	Hyperlink	Notes	$CAT-GENERAL$	Industrial Category
Industrial Wastewater	ww_industrial	Industrial liquid waste, driven by the production of industrial goods			Default assumption for treatment pathway: taken from V5, C6, Table 6.5 of IPCC GNGHGI as mean of urban high and urban low income. Sewerage is uniformly distributed betweeen all sewered categories (no treat, treat anerobic, treat aerobic). Septic/Latrine is reclassifed to sewer/untreated.	none	industry
Rural Domestic Wastewater	ww_domestic_rural	Domestic urban wastewater–generally composed of human waste (sewage) and driven by population. Urban populations generally have higher access to sewerage.			Default assumption for treatment pathway: taken from V5, C6, Table 6.5 of IPCC GNGHGI as mean of urban high and urban low income. Sewerage is uniformly distributed betweeen all sewered categories (no treat, treat anerobic, treat aerobic).	rural	none
Urban Domestic Wastewater	ww_domestic_urban	Domestic urban wastewater–generally composed of human waste (sewage) and driven by population. Urban populations generally have higher access to sewerage.			Default assumption for treatment pathway: taken from V5, C6, Table 6.5 of IPCC GNGHGI from rural. Sewerage is assumed to be untreated.	urban	none

Variables

Variables associated with the Liquid Waste subsector are shown below.

Trajectories of the following variables are needed for the Liquid Waste subsector. The categories that variables apply to are described in the category column.

Variable Type	Variable	Information	Variable Schema	Categories	Reference	Default Value	Default LHS Scalar Minimum at Final Time Period	Default LHS Scalar Maximum at Final Time Period	Simplex Group	Emissions Total by Gas Component	$CAT-WASTEWATER-TREATMENT$	IPCC Emissions Sector Codes	IPCC Equation Reference	Notes
Input	(Optional) Elasticity of Protein in Diet to GDP per Capita	Used if run indepedently from the AFOLU model. In the integrated modeling framework, growth in demand per capita for livestock is used to estimate growth in protein contained in diets. However, the model may be run in isolation. In this case, users can use an elasticity in combination with the fraction of the population that does not eat red meat.	elasticity_protein_in_diet_to_gdppc	none		0	0.8	1.2		0	none
Input	Average Protein Consumption Per Capita	Daily protein consumption per person in kg	qty_protein_per_capita_$UNIT-MASS$ ($UNIT-MASS$ = kg)	none		0	1.0	1.0		0	none			Estimated starting with point estimate of 65.7 grams per person per day in 1984 (see Sepulveda (1984)). Then Andreoli et al. (2021) was used to estimate that protein consumption in latin america from animal protein was approximately 27.5 grams per person per day in 1984, which then grew to 37.5 by 2017 (an increase of 10 grams per day). This gives the baseline of 0.0777 kg per person per day. Consumption of vegetable protein in a standard diet is assumed to be constant.
Input	BOD Correction Factor for TOW	Correction factor for average annual BOD per capita that represents sewage from commercial and industrial operations.	physparam_wali_tow_dom_generation_correction_factor	none		0	0.8	1.2		0	none			See I in Equation 6.3 (IPCC GNGHGI V5,C6)
Input	BOD per Capita	Annual biochemical oxygen demand (BOD) per person in kg. Table 6.4 in IPCC Guidelines for NGHG Inventories shows regional factors.	physparam_wali_daily_$UNIT-MASS$_bod_per_capita ($UNIT-MASS$ = kg)	none		0	0.78	1.22		0	none
Input	COD per GDP	Average annual chemical oxygen demand (COD) in industrial water per GDP at time \(t = 0\). Mean and range derived from Volume 5, Table 6.9 in IPCC Guidelines for NGHG Inventories.	physparam_wali_$UNIT-MASS$_cod_per_mmm_gdp ($UNIT-MASS$ = tonne)	none		0	0.37	2.17		0	none
Input	Factor for Nitrogen in Non-Consumed Protein Disposed in Sewer System	\(F_{NON-CON}\) in Equation 6.10 in V5, C6 IPCC GNGHGI (2019R). Default values by region are available in Table 6.10A.	param_wali_f_noncon	none		0	1.0	1.0		0	none			See V5, C6, Table 6.10A IPCC GNGHGI
Input	Fraction of Protein in Diet with Red Meat		frac_wali_protein_in_diet_with_red_meat	none		0	1.0	1.0		0	none			Used to estimate protein content in domestic wastewater. Protein (see IPCC GHG Guidance) . See Table 1 in Papier et al. (2019) for the source of these numbers.
Input	Fraction of Protein in Diet without Red Meat		frac_wali_protein_in_diet_without_red_meat	none		0	1.0	1.0		0	none
Input	Initial Per Capita Annual Domestic Wastewater Generated	Represents the estimated volume, in \(\text{m}^3\)/year, that each person produces in domestic wastewater. This production This value is modified by the log elasticity of production to gdp/capita. Increasing GDP/Capita is associated with increasing per capita liquid waste generation; see Jones, Vliet, Qadir, and Bierkens (2021).	qty_wali_$UNIT-VOLUME$_$CAT-WASTE-LIQUID$_per_capita ($UNIT-VOLUME$ = m3)	ww_domestic_rural``|``ww_domestic_urban		0	1.0	1.0		0	none			Default global average of 49 m3/person/year from Jones, Vliet, Qadir, and Bierkens.
Input	Initial Per GDP Annual Industrial Wastewater Generated	Represents the estimated quantity, in m3/year, produced per billion $ GDP.	qty_wali_$UNIT-VOLUME$_$CAT-WASTE-LIQUID$_per_gdp ($UNIT-VOLUME$ = m3)	ww_industrial		0	1.0	1.0		0	none
Input	Log Elasticity DWW Production to GDP Per Capita	Log elasticity \(\varepsilon\) of domestic wastewater production per capita to GDP/capita. For a year over year growth in GDP/capita \(\Delta g\), the change in domestic wastewater production per capita is estimated as \(\Delta W_{d} = (1 + \Delta g)^{\varepsilon} - 1\).	logelasticity_wali_qty_prod_to_gdp_per_capita	none	https://essd.copernicus.org/articles/13/237/2021/	0	0.8	1.2		0	none			Derived from Jones, Vliet, Qadir, and Bierkens : Country-level and gridded estimates of wastewater production, collection, treatment and reuse, Earth Syst. Sci. Data, 13, 237–254, https://doi.org/10.5194/essd-13-237-2021, 2021. See table 3.1 for the regression coefficient associated with the log production of wastewater, found as 0.31.
Input	Maximum BOD \(\text{CH}_4\) Producing Capacity	\(B_O\) from IPCC Guidelines for NGHG Inventories–or maximum CH4 producing capacity, kg \(\text{CH}_4\)/kg BOD.	physparam_wali_bo_tonne_$EMISSION-GAS$_tonne_bod ($EMISSION-GAS$ = ch4)	none		0	0.8	1.2		0	none			See V5, C6, Table 6.2 IPCC GNGHGI
Input	Maximum COD \(\text{CH}_4\) Producing Capacity	\(B_O\) from IPCC Guidelines for NGHG Inventories–or maximum CH4 producing capacity, kg \(\text{CH}_4\)/kg COD.	physparam_wali_bo_tonne_$EMISSION-GAS$_tonne_cod ($EMISSION-GAS$ = ch4)	none		0	0.8	1.2		0	none			See V5, C6, Table 6.2 IPCC GNGHGI
Input	Nitrogen Density of Industrial Wastewater	Nitrogen density of industrial wastewater	density_wali_$UNIT-MASS$_n_per_$UNIT-VOLUME$_$CAT-WASTE-LIQUID$ ($UNIT-MASS$ = kg, $UNIT-VOLUME$ = m3)	ww_industrial		0	0.5	2.0		0	none			See V5, C6, Table 6.12 IPCC GNGHGI
Input	Phosphorous Per BOD Factor	Ratio of phosphorous to BOD. Unitless. Used in calculating benefits of water treatment	physparam_wali_p_per_bod	none		0	0.8	1.6		0	none
Input	Phosphorous Per COD Factor	Ratio of phosphorous to COD. Unitless. Used in calculating benefits of water treatment	physparam_wali_p_per_cod	none		0	0.8	1.6		0	none
Input	Scalar to Account for Nitrogen in Household Products	\(N_{HH}\) in Equation 6.10 in V5, C6 IPCC GNGHGI (2019R). Default values by region are available in Table 6.10A.	param_wali_n_hh_scalar	none		0	1.0	1.0		0	none			See V5, C6, Table 6.10A IPCC GNGHGI
Input	Treatment Fraction Advanced Aerobic		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_advanced_aerobic	all		0	1.0	1.0	1.0	0	treated_advanced_aerobic
Input	Treatment Fraction Advanced Anaerobic		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_advanced_anaerobic	all		0	1.0	1.0	1.0	0	treated_advanced_anaerobic
Input	Treatment Fraction Improved Latrine		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_latrine_improved	all		0	1.0	1.0	1.0	0	treated_latrine_improved
Input	Treatment Fraction Primary		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_primary	all		0	1.0	1.0	1.0	0	treated_primary
Input	Treatment Fraction Secondary Aerobic		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_secondary_aerobic	all		0	1.0	1.0	1.0	0	treated_secondary_aerobic
Input	Treatment Fraction Secondary Anaerobic		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_secondary_anaerobic	all		0	1.0	1.0	1.0	0	treated_secondary_anaerobic
Input	Treatment Fraction Septic		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_septic	all		0	1.0	1.0	1.0	0	treated_septic
Input	Treatment Fraction Unimproved Latrine		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_latrine_unimproved	all		0	1.0	1.0	1.0	0	treated_latrine_unimproved
Input	Treatment Fraction Untreated No Sewerage		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_untreated_no_sewerage	all		0	1.0	1.0	1.0	0	untreated_no_sewerage
Input	Treatment Fraction Untreated With Sewerage		frac_wali_$CAT-WASTE-LIQUID$_treatment_path_untreated_with_sewerage	all		0	1.0	1.0	1.0	0	untreated_with_sewerage

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Wastewater Treatment (TRWW)

Wastewater can be treated using a variety of pathways. Note that aerobic and septic pathways produce sludge, which can disposed of in a variety of ways; the SISEPUEDE model does not currently integrate sludge removal and disposal from aerobic and septic treatment pathways.

Note

IPCC accounting (IPCC GNGHGI V5, C6 2019R) calls for emissions from secondary sludge extracted from aerobic WWTPs to be divided between decentralized treatment (uncollected) and centralized treatment, where centralized aerobic treatment includes sludge treatment on-site, accounting for emissions of sludge due to treatment–e.g., from anaerobic decomposition–in the Wastewater Treatment sector. Instead, SISEPUEDE accounts for all emissions from sludge treatment in the Solid Waste sector.

Categories

Categories associated with Wastewater Treatment are identified by the $CAT-WASTEWATER-TREATMENT$ variable schema element and shown in the category attribute table shown below.

Wastewater Treatment categories ($CAT-WASTEWATER-TREATMENT$ attribute table)

Category Name	$CAT-WASTEWATER-TREATMENT$	Description	Data Source	Hyperlink	Notes	Default TOW Removal Fraction	Default TOW Removal Fraction Lower Bound	Default TOW Removal Fraction Upper Bound
Aerobic Treatment - Advanced	treated_advanced_aerobic	Wastewater that is treated in centralized or decentralized aerobic plants. The \(\text{CH}_4\) emissions accounted for the process itself. Sludge removal and treatment is then sent to the Solid Waste treatment sector. Includes primary, secondary, and tertiary aerobic biological treatment. Primary only should be treated in the primary category, while primary+secondary should be treated in the secondary_aerobic treatment category.			In aerobic treatment facilities, waste is removed as sludge.	0.9	0.8	0.95
Aerobic Treatment - Secondary	treated_secondary_aerobic	Primary and secondary treatment (mechanical + biological) aerobic wastewater treatment facilities.				0.85	0.8	0.9
Anaerobic Treatment - Advanced	treated_advanced_anaerobic	Wastewater that is treated in anaerobic plants, deep lagoons, and other treatment facilities where biological decomposition creates anaerobic \(\text{CH}_4\) emissions. Excludes shallow lagoons. Includes primary, secondary, and tertiary anaerobic biological treatment. Primary only should be treated in the primary category, while primary+secondary should be treated in the secondary_anaerobic treatment category.			In anaerobic treatment facilities, waste is decomposed anaerobically, creating \(\text{CH}_4\) emissions.	0.9	0.8	0.95
Anaerobic Treatment - Secondary	treated_secondary_anaerobic	Primary and secondary treatment (mechanical + biological) anaerobic wastewater treatment facilities.				0.85	0.8	0.9
Latrines - Improved	treated_latrine_improved	Improvemed latrines are assumed to be associated with higher anaerobic decomposition activity, releasing more methane.				0.6	0.4	1
Latrines - Unimproved	treated_latrine_unimproved	Unimproved latrines				0.1	0.05	0.15
Primary Treatment	treated_primary	Primary treatment only (mechanical) wastewater treatment facilities.				0.4	0.25	0.5
Septic	treated_septic	Septic tanks, which are a common treatment option in rural areas.			In properly managed septic tanks, a fraction of waste is removed as sludge, which is then disposed of in the solid waste stream.	0.625	0.5	0.6
Untreated No Sewerage	untreated_no_sewerage	Wastewater that is untreated without sewerage. Sewerage reduces methane emissions from anaerobic decomposition. Incudes sea, river, and lake disharge as well as open, stagnant sewers.				0	0	0.1
Untreated With Sewerage	untreated_with_sewerage	Wastewater that is sent to sewers (clean, closed, moving), but is not treated afterwards. While there are no \(\text{CH}_4\) emissions from these sewers, effluent contains significant emissions.				0	0	0.1

Variables

Variables associated with the Wastewater Treatment subsector are shown below.

Trajectories of the following variables are needed for the Wastewater Treatment subsector. The categories that variables apply to are described in the category column.

Variable Type	Variable	Information	Variable Schema	Categories	Reference	Default Value	Default LHS Scalar Minimum at Final Time Period	Default LHS Scalar Maximum at Final Time Period	Simplex Group	Emissions Total by Gas Component	IPCC Emissions Sector Codes	IPCC Equation Reference	Notes
Input	\(\text{K}_{REM}\) Sludge Factor	Fraction of raw sludge removed from aerboic treatmeant plants	physparam_krem_sludge_factor_$CAT-WASTEWATER-TREATMENT$	treated_advanced_aerobic``|``treated_secondary_aerobic		0	0.46	1.39		0			See V5, C6, Equation 6.3B and Table 6.6A in 2019R IPCC GNGHGI. Increasing this factor can represent investments in upgrades to aerobic treatment (or new facilities).
Input	\(\text{N}_2\text{O}\) Wastewater Treatment Emission Factor	Nitrus oxide emission factor for wastewater treatment as a function of total nitrogen.	ef_trww_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_n ($UNIT-MASS$ = g, $EMISSION-GAS$ = n2o)	all		0	0.8	1.2		0			See V5, C6, Equation 6.10 and Equation 6.13 for industrial wastewater and Table 6.8A (2019R) for emission factors for industrial and domestic wastwater For primary treatment category, use default emission factor (see 6A.4)
Input	Biogas Recovery Factor at Wastewater Treatment Plants	Fraction of biogas recovered from treatment	gasrf_trww_biogas_$CAT-WASTEWATER-TREATMENT$	treated_advanced_aerobic``|``treated_advanced_anaerobic``|``treated_secondary_aerobic``|``treated_secondary_anaerobic		0	1.0	1.0		0
Input	Fraction of Nitrogen Removed in Treatment	Wastewater treatment removes some fraction of nitrogen, similar to the methane correction factor. See V5, C6, Equation 6.8 and Tables 6.10B and 6.10C.	frac_trww_n_removed_$CAT-WASTEWATER-TREATMENT$	all		0	1.0	1.0		0			See V5, C6, Table 6.10C (2019R) for default removal fractions by type
Input	Fraction of Phosphorous Removed in Treatment		frac_trww_p_removed_$CAT-WASTEWATER-TREATMENT$	all		0	1.0	1.0		0			See Table 7 in IADB Report on Urban Wastewater Treatment in Brazil for more information on phosphorous removal by different plant types. NOTE: default factors of 0.35 are used for most water treatment plants (<0.35 is specified in Table 7). Advanced plants are treated as the conceptual mean of “Anaerobic pond + facult. pond + maturation pond”, “UASB + dissolved-air flotation”, and “UASB + maturation ponds”, which have values of >0.5, 75-88, and >0.5. Using nominal values of 0.5, 0.5, and 81.5, this gives a mean 0.605.
Input	Fraction of Total Organic Waste Removed in Treatment		frac_trww_tow_removed_$CAT-WASTEWATER-TREATMENT$	all		0	0.8	1.2		0			See V5, C6, Equation 6.3D (2019R) for total oranics in domestic wastewater effluent See Table 6.6B for removal fractions by treatment type
Input	Septic Sludge Compliance Fraction	Fraction the population managing their septic tank in compliance with the sludge removal instruction of their septic system	frac_sludge_compliant_$CAT-WASTEWATER-TREATMENT$	treated_septic		0	0.5	1.5		0			See V5, C6, Equation 6.3C
Input	Wastewater Treatment Methane Correction Factor		mcf_trww_$CAT-WASTEWATER-TREATMENT$	all		0	0.8	1.2		0			See Table 6.3 in IPCC Guidelines for NGHG Inventories
Output	\(\text{CH}_4\) Emissions from Wastewater Treatment	Methane emissions from wastewater treatment	emission_co2e_$EMISSION-GAS$_trww_$CAT-WASTEWATER-TREATMENT$_treatment ($EMISSION-GAS$ = ch4)	all		0	1.0	1.0		1
Output	\(\text{N}_2\text{O}\) Emissions from Wastewater Effluent	Nitrus oxide emissions from protein content in wastewater.	emission_co2e_$EMISSION-GAS$_trww_$CAT-WASTEWATER-TREATMENT$_effluent ($EMISSION-GAS$ = n2o)	all		0	1.0	1.0		1
Output	\(\text{N}_2\text{O}\) Emissions from Wastewater Treatment	Nitrus oxide emissions from treatment processes.	emission_co2e_$EMISSION-GAS$_trww_$CAT-WASTEWATER-TREATMENT$_treatment ($EMISSION-GAS$ = n2o)	all		0	1.0	1.0		1
Output	Biogas Recovered from Wastewater Treatment Plants		gasrecovered_trww_biogas_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Mass of Sludge Produced	Total mass of sludge produced from wastewater treatment (aerobic and septic treatment pathways) in tonnes	qty_trww_sludge_produced_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	treated_advanced_aerobic``|``treated_secondary_aerobic``|``treated_septic		0	1.0	1.0		0			Total mass of sludge produced, which then is sent to the solid waste model.
Output	Total BOD Organic Waste in Effluent	Total organic waste in effluent released from different pathways from BOD	qty_trww_tow_in_effluent_bod_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total BOD Removed in Treatment	Total BOD treated by wastewater treatment type	qty_trww_bod_removed_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total COD Organic Waste in Effluent	Total organic waste in effluent released from different pathways from BOD	qty_trww_tow_in_effluent_cod_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total COD Removed in Treatment	Total COD treated by wastewater treatment type	qty_trww_cod_removed_$CAT-WASTEWATER-TREATMENT$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total Nitrogen Removed in Treatment		qty_trww_n_removed_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total Nitrogen in Effluent		qty_trww_n_in_effluent_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total Phosphorous Removed in Treatment		qty_trww_p_removed_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total Phosphorous in Effluent		qty_trww_p_in_effluent_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Volume of Wastewater Treated		vol_trww_ww_$CAT-WASTEWATER-TREATMENT$_$UNIT-VOLUME$ ($UNIT-VOLUME$ = m3)	all		0	1.0	1.0		0

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Solid Waste (WASO)

Solid waste is generated by consumption. Growth in domestic consumption in is driven by GDP per capita, while growth in industrial consumption is driven by production (represented by value added). Solid waste can reach one of four final states: incineration (or open-burning), landfilled, recycling (or composting/anaerobic biogas production for food and yard waste).

Note

Process emissions for recycling of recyclable materials that affect virgin production–glass, metals, paper, plastic, rubber and leather, textiles, wood–are treated in Industrial Processes and Product Use.

Categories

Categories associated with Solid Waste are identified by the $CAT-WASTE-SOLID$ variable schema element and shown in the category attribute table shown below.

Note

The solid waste attribute table requires the specification of parameters used to characterize different types of waste. These parameters–with the exception of industrial and chemical waste–are derived from default values provided by the IPCC in Volume 5, Chapter 2, Table 2.4 of the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (which contains the table) for the source of parameters. Industrial parameters come from Volume 5, Chapter 2, Table 2.5.

Solid waste categories ($CAT-WASTE-SOLID$ attribute table)

Category Name	$CAT-WASTE-SOLID$	Description	Data Source	Hyperlink	Notes	Dry Matter Content as Fraction Wet Weight	DOC Content as Fraction Wet Waste	DOC Content as Fraction Dry Waste	DOCf Degradable	Total Carbon Content as Fraction Dry Weight	Fossil Carbon Fraction as Fraction Total Carbon	Food Category	Sewage Sludge Category	$CAT-INDUSTRY$
Chemical and Industrial	chemical_industrial	Industrial and chemical solid waste - includes mercury containing devices, computers and electronics, batteries, silica gel, and other chemical solid waste.			See Princeton Environmental Health and Safety for the delineation of these industrial subcategories. See Volume 5, Chapter 2, Table 2.5 in the IPCC National Greenhouse Gas Inventories for the source of Industrial waste default paramters (other). Note that dry matter content is assumed to be 1 - water content and DOC for dry waste is assumed to be the same as DOC for wet waste.	0.9	0.01	0.01	0	0.5	0.9	0	0	none
Food	food	Food and organic waste, excluding yard and garden waste				0.4	0.15	0.38	0.7	0.38	0	1	0	none
Glass	glass	Glass				1	0	0	0	0	0	0	0	recycled_glass
Metals	metal	Metals				1	0	0	0	0	0	0	0	recycled_metals
Other	other	Other waste not mentioned in any other category, including sanitary napkins and diapers.				0.9	0	0	0	0.03	1	0	0	none
Paper	paper	Paper products, including cardboard				0.9	0.4	0.44	0.5	0.46	0.01	0	0	recycled_paper
Plastic	plastic	Plastic				1	0	0	0	0.75	1	0	0	recycled_plastic
Rubber and Leather	rubber_leather	Rubber and leather			Assigned DOCf to less decompostable waste in IPCC FOD model.	0.84	0.39	0.47	0.1	0.67	0.2	0	0	recycled_rubber_and_leather
Sanitary Napkins	nappies	Sanitary napkins, nappies, diapers				0.4	0.24	0.6	0.5	0.7	0.1	0	0	none
Sludge	sludge	Sludge from wastewater			Note that, in sewage sludge, fossil carbon can usually be neglected (IPCC Guidelines for NGHG Inventories, 5.19). See Table 5.2 for defaults. The Total Carbon Sewage sludge is estimated as a product of wastewater treatment from aerobic treatment facilities and septic tanks. Assigned DOCf to less decompostable waste in IPCC FOD model.	0	0.05	0.3	0.1	0.3	0	0	1	none
Textiles	textiles	Clothing and textiles				0.8	0.24	0.3	0.5	0.5	0.2	0	0	recycled_textiles
Wood	wood	Wood and wood products				0.85	0.43	0.5	0.1	0.5	0	0	0	recycled_wood
Yard	yard	Garden and yard waste				0.4	0.2	0.49	0.4	0.49	0	0	0	none

Variables

Variables associated with the Solid Waste subsector are shown below.

Trajectories of the following variables are needed for the Solid Waste subsector. The categories that variables apply to are described in the category column.

Variable Type	Variable	Information	Variable Schema	Categories	Reference	Default Value	Default LHS Scalar Minimum at Final Time Period	Default LHS Scalar Maximum at Final Time Period	Simplex Group	Emissions Total by Gas Component	IPCC Emissions Sector Codes	IPCC Equation Reference	Notes
Input	\(\text{CH}_4\) Anaerobic Biogas Emission Factor	Emission factor representing fugitive emissions of methane from anaerobic decomposition in biogas facilities.	ef_waso_biogas_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4, $UNIT-MASS$ = kg)	food``|``sludge``|``yard		0	0.57	1.43		0			Default set as mean between wet and dry weight factors from Volume 5, Table 4.1 in IPCC Guidelines for NGHG Inventories.
Input	\(\text{CH}_4\) Composting Emission Factor	Emission factor representing emissions of methane from composting of organic materials	ef_waso_compost_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4, $UNIT-MASS$ = kg)	food``|``sludge``|``yard		0	0.57	1.43		0			Default set as mean between wet and dry weight factors from Volume 5, Table 4.1 in IPCC Guidelines for NGHG Inventories.
Input	\(\text{CH}_4\) ISW Incineration Emission Factor	Based on IPCC Tier 1 approach–\(\text{CH}_4\) emissions from incineration or open burning of ISW.	ef_waso_incineration_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_isw ($EMISSION-GAS$ = ch4, $UNIT-MASS$ = kg)	none		0	0.2	2.0		0			Nominal value is mean across all types of incineration technology and open burning (6500g/t waste) (Volume 5, Table 5.3), or 998.7 g/tonne. This is rounded up to 1 kg/tonne, or 0.001 kg/kg.
Input	\(\text{CH}_4\) MSW Incineration Emission Factor	Based on IPCC Tier 1 approach–\(\text{CH}_4\) emissions from incineration or open burning of MSW.	ef_waso_incineration_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_msw ($EMISSION-GAS$ = ch4, $UNIT-MASS$ = kg)	none		0	0.2	2.0		0			Nominal value is mean across all types of incineration technology and open burning (6500g/t waste) (Volume 5, Table 5.3), or 998.7 g/tonne. This is rounded up to 1 kg/tonne, or 0.001 kg/kg.
Input	\(\text{CH}_4\) Recovery Factor Landfill Gas	Factor representing how much methane is extracted from landfill gas that is recovered.	gasrf_waso_landfill_to_$EMISSION-GAS$ ($EMISSION-GAS$ = ch4)	none		0	1.0	1.0		0
Input	\(\text{N}_2\text{O}\) Composting Emission Factor	Emission factor representing emissions of nitrus oxide from composting of organic materials	ef_waso_compost_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = n2o, $UNIT-MASS$ = kg)	food``|``sludge``|``yard		0	0.57	1.43		0			Default is set as mean between wet and dry weight factors from Volume 5, Table 4.1 in IPCC Guidelines for NGHG Inventories.
Input	\(\text{N}_2\text{O}\) Incineration Emission Factor	Based on IPCC Tier 2 approach (default emission factors with waste composition)	ef_waso_incineration_$UNIT-MASS$_$EMISSION-GAS$_per_$UNIT-MASS$_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = n2o, $UNIT-MASS$ = tonne)	all		0	1.0	1.0		0			Default values taken from IPCC GNGHGI V5, C5, Tables 5.4 (MSW defaults, excluding plastic, wood, paper, and sludge) and 5.5 (industrial, sludge, wood, paper, and plastic). Note that the emission factors are unitless and are converted to tonne/tonne.
Input	Average Annual Waste Transported Per Waste Collection Vehicle	Average annual total waste collected per waste collection vehicle. Used to calculate a marginal increase in heavy transport transportation demand resulting from an increase in waste collection, which is passed to the transportation model.	qty_waso_annual_waste_collected_$UNIT-MASS$_per_vehicle ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Input	Average Methane Correction Factor at Landfills	The Methane Correction Factor represents different management approaches for solid waste disposal at landfills. See Volume 5, Chapter 3, Table 3.1 of IPCC Guidelines for National Greenhouse Gas Inventories for default MCFs.	mcf_waso_average_landfilled	none		0	1.0	1.0		0
Input	Average Methane Correction Factor for Open Dumping	The Methane Correction Factor represents different management approaches for solid waste disposal at landfills. See Volume 5, Chapter 3, Table 3.1 of IPCC Guidelines for National Greenhouse Gas Inventories for default MCFs.	mcf_waso_average_open_dump	none		0	1.0	1.0		0
Input	Average Oxidization Factor at Landfills	Oxidization factor (see V5, C3, Table 3.2) for landfills. The oxidization factor represents a practice at well-managed landfills of covering landfills with with \(\text{CH}_4\) oxidising material–e.g., soild or compost. Should not exceed 0.1.	oxf_waso_average_landfilled	none		0	1.0	1.0		0
Input	Average VKMT Per Waste Collection Vehicle	Average annual Vehicle Kilometers Traveled (VKMT) per waste collection vehicle. Used to calculate a marginal increase in heavy transport transportation demand resulting from an increase in waste collection, which is passed to the transportation model.	vkmt_per_vehicle_waso	none		0	1.0	1.0		0
Input	Biogas Recovery Factor	Factor representing faction of biogas recovered for energy production. Recovery of biogass prevents emissions.	gasrf_waso_biogas	none		0	1.0	1.0		0
Input	Elasticity of Municipal Solid Waste Produced to GDP per Capita	The elasticity of waste per capita to GDP per capita, which is used to estimate increases in waste as population and GDP/capita rise.	elasticity_waso_msw_to_gdppc_$CAT-WASTE-SOLID$	all		0	1.0	1.0		0
Input	Fraction of ISW Incineration Recovered for Energy	Incineration can be open burning or for energy. This fraction \(a\) represents the how much ISW is incinerated for energy production. \(1 - a\) is then assumed to be some mix of open burning and icineration. Incinerable waste can be passed to the Energy model as a Fuel.	frac_waso_isw_incinerated_recovered_for_energy	none		0	1.0	1.0		0
Input	Fraction of Landfill Gas Recovered at Landfills	Represents the proportion of methane emitted at landfills that is captured. This represents an average over the country across all landfills, as SISEPUEDE does not distinguish between sanitary landfills, controlled landfills, or other landfills.	frac_waso_landfill_gas_recovered	none		0	1.0	1.0		0
Input	Fraction of Landfill Gas Recovered for Energy	Landfil gas can be captured and converted to energy. This fraction \(a\) represents the how much landfil gas that is captured is converted to energy. \(1 - a\) is then assumed to be recovered and not converted to energy (or flared). Landfill gas can be passed to the Energy model as a Fuel.	frac_waso_lgc_recovered_for_energy	none		0	1.0	1.0		0
Input	Fraction of MSW Incineration Recovered for Energy	Incineration can be open burning or for energy. This fraction \(a\) represents the how much MSW is incinerated for energy production. \(1 - a\) is then assumed to be some mix of open burning and icineration. Incinerable waste can be passed to the Energy model as a Fuel.	frac_waso_msw_incinerated_recovered_for_energy	none		0	1.0	1.0		0
Input	Fraction of Methane Flared at Composting Facilities		frac_waso_compost_methane_flared	none		0	1.0	1.0		0
Input	Fraction of Non-Recycled Solid Waste Incinerated	Proportion of non-recycled municipal waste that is burned in incineration facilities and in open burn sites.	frac_waso_non_recycled_incinerated	none		0	1.0	1.0	1.0	0
Input	Fraction of Non-Recycled Solid Waste Landfilled	Proportion of non-recycled municipal waste that is landfilled. Landfills include different levels of management	frac_waso_non_recycled_landfilled	none		0	1.0	1.0	1.0	0
Input	Fraction of Non-Recycled Solid Waste Open Dumps	Proportion of non-recycled municipal waste that is ends up in open dumpsites	frac_waso_non_recycled_open_dump	none		0	1.0	1.0	1.0	0
Input	Fraction of Waste Composted	Fraction of waste in category CAT-WASTE-SOLID composted. This value should be \(\in [0, 1]\).	frac_waso_compost_$CAT-WASTE-SOLID$	food``|``sludge``|``yard		0	1.0	1.0		0
Input	Fraction of Waste Recycled	Fraction of waste in category CAT-WASTE-SOLID that is recycled. This value should be \(\in [0, 1]\).	frac_waso_recycled_$CAT-WASTE-SOLID$	glass``|``metal``|``paper``|``plastic``|``rubber_leather``|``textiles``|``wood		0	1.0	1.0		0
Input	Fraction of Waste Treated Anaerobically	Fraction of waste in category CAT-WASTE-SOLID treated anaerobically. This value should be \(\in [0, 1]\).	frac_waso_biogas_$CAT-WASTE-SOLID$	food``|``sludge``|``yard		0	1.0	1.0		0
Input	Historical Back Projection Growth Rate in Solid Waste Generation	Primary a calibration parameter if using the back-projection method for solid waste. The growth rate at time \(t = 0\) is applied backwards to estimate waste landfilled in previous years. The back projection method should only be used in the absence of historical data.	historical_back_projection_growth_rate	none		0	1.0	1.0		0
Input	Initial Composition Fraction Industrial Solid Waste	Represents the fraction of all industrial solid waste represented by this type	frac_waso_initial_composition_ind_$CAT-WASTE-SOLID$	all		0	1.0	1.0	2.0	0			Defaults taken as average between Central and South American from V5, C2
Input	Initial Composition Fraction Municipal Solid Waste	Represents the initial fraction of all domestic solid waste represented by this type. Per capita growth rates in waste generated by category are projected by applying elasticities to changes in gdp/capita.	frac_waso_initial_composition_mun_$CAT-WASTE-SOLID$	all		0	1.0	1.0	3.0	0
Input	Initial Per Capita Municipal Solid Waste Generated	Represents the estimated quantity, in kg/person, of solid waste generated per person at time \(t = 0\). The total waste generated per person is then estimated for each waste composition category using the elasticity of waste production to income (GDP/Capita).	qty_waso_initial_municipal_waste_$UNIT-MASS$_per_capita ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0			Country level data are available from the World Bank Waste Database. Additional regional defaults are available in V5, C2, Table 2.1 of IPCC GNGHGI for default rates by region.
Input	K	Methane Generation Rate \(k\), a physical parameter characterizing the mass decay half-life of each type of waste that is landfilled. Default values of k are taken from Volume 5, Chapter 3, Table 3.3 of the IPCC Guidelines for National Greenhouse Gas Inventories.	physparam_waso_k_$CAT-WASTE-SOLID$	all		0	1.0	1.0		0			Note that, for a half life t, the factor k is found as \(k = \ln(2)/t\).
Input	Per GDP Industrial Solid Waste Generated	Industrial waste generated per GDP	qty_waso_industrial_waste_$UNIT-MASS$_per_mmm_gdp ($UNIT-MASS$ = kt)	none		0	1.0	1.0		0
Input	Waste Per Capita Scale Factor	Use the scale factor to represent reduction measures in waste production within a category; for example, waste reduction campaigns might affect all categories, but a tax on plastic might only reduce the generation of plastic waste. IMPORTANT NOTE: For the sludge cateogry, this factor will only affect sludge that is specified exogenously. It will not affect sludge produced from aerobic and septic wastewater treatement in the Wastewater Treatment subsector. Any interventions to reduce sludge produced in wastewater treatment should be addressed in the wastewater treatment sector.	factor_waso_waste_per_capita_scalar_$CAT-WASTE-SOLID$	all		0	1.0	1.0		0
Output	\(\text{CH}_4\) Emissions from Anaerobic Biogas	Emissions from anaerobic decomposition organic waste in biogas plants. This waste stream flow is used to generate energy. Note that methane leakage from these plants is assumed to be 5% with a range of 0 - 10 % (see 2006 IPCC GHG guidance Volume 5, Chapter 4, page 4.4)	emission_co2e_$EMISSION-GAS$_waso_biogas_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4)	food``|``sludge``|``yard		0	1.0	1.0		1
Output	\(\text{CH}_4\) Emissions from Composting		emission_co2e_$EMISSION-GAS$_waso_compost_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4)	food``|``sludge``|``yard		0	1.0	1.0		1
Output	\(\text{CH}_4\) Emissions from Incineration	Total \(\text{CH}_4\) emissions from incineration (combined MSW and ISW)	emission_co2e_$EMISSION-GAS$_waso_incineration ($EMISSION-GAS$ = ch4)	none		0	1.0	1.0		1
Output	\(\text{CH}_4\) Emissions from Landfills	Captures \(\text{CH}_4\) emissions from landfills (\(\text{CH}_4\) is assumed to be 50% of landfill gas.	emission_co2e_$EMISSION-GAS$_waso_landfilled_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4)	all		0	1.0	1.0		1
Output	\(\text{CH}_4\) Emissions from Open Dumping	Captures \(\text{CH}_4\) emissions from open dumping. Aerobic decomposition can occur at lower levels with open dumping, but there is no collection of gas.	emission_co2e_$EMISSION-GAS$_waso_open_dump_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = ch4)	all		0	1.0	1.0		1
Output	\(\text{CO}_2\) Emissions from Incineration	Total \(\text{CO}_2\) emissions from incineration (combined MSW and ISW)	emission_co2e_$EMISSION-GAS$_waso_incineration ($EMISSION-GAS$ = co2)	none		0	1.0	1.0		1
Output	\(\text{N}_2\text{O}\) Emissions from Composting		emission_co2e_$EMISSION-GAS$_waso_compost_$CAT-WASTE-SOLID$ ($EMISSION-GAS$ = n2o)	food``|``sludge``|``yard		0	1.0	1.0		1
Output	\(\text{N}_2\text{O}\) Emissions from Incineration	Total \(\text{N}_2\text{O}\) emissions from incineration (combined MSW and ISW)	emission_co2e_$EMISSION-GAS$_waso_incineration ($EMISSION-GAS$ = n2o)	none		0	1.0	1.0		1
Output	Biogas Recovered from Anaerobic Facilities	Biogas is a mixture of methane, carbon dioxide, water vapor, hydrogen suflide, and other gases. See The EPA for an overview of anaerobic digestion and biogas.	gasrecovered_waso_biogas_anaerobic_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Biogas Recovered from Landfills	Mass of methane recovered from landfill gas that is colleted.	gasrecovered_waso_biogas_landfills_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total ISW Recovered for Energy	Total quantity of industrial solid waste that is recovered for energy use.	qty_waso_isw_recovered_for_energy_incineration_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total MSW Recovered for Energy	Total quantity of municipal solid waste that is recovered for energy use.	qty_waso_msw_recovered_for_energy_incineration_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	none		0	1.0	1.0		0
Output	Total Solid Waste Produced	Total waste produced from industry and municipal sources.	qty_waso_total_$CAT-WASTE-SOLID$_produced_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total Waste Anaerobic Biogas	Total quantity of waste sent to anaerobic biogas facilities.	qty_waso_biogas_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	food``|``sludge``|``yard		0	1.0	1.0		0
Output	Total Waste Composted	Total quantity of waste composted in tonnes.	qty_waso_compost_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	food``|``sludge``|``yard		0	1.0	1.0		0
Output	Total Waste Incinerated	Total quantity of waste incinterated in tonnes.	qty_waso_incinerated_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total Waste Landfilled	Total quantity of waste landfilled in tonnes.	qty_waso_landfilled_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total Waste Open Dumped	Total quantity of waste open dumped in tonnes.	qty_waso_open_dump_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	all		0	1.0	1.0		0
Output	Total Waste Recycled	Total quantity of waste recycled in tonnes.	qty_waso_recycled_$CAT-WASTE-SOLID$_$UNIT-MASS$ ($UNIT-MASS$ = tonne)	glass``|``metal``|``paper``|``plastic``|``rubber_leather``|``textiles``|``wood		0	1.0	1.0		0