india city archetype: steady roller · india city archetype: steady roller 1 analysis is based on...
TRANSCRIPT
Disclaimer: This decision tree is based on market information collected for India, as well as cost-modeling for common types of systems that may be constructed there. It is designed to provide high-level, directional guidance for decision makers. It is not intended to take the place of a detailed feasibility assessment for a specific project. Actual life cycle costs for any system are driven by many localized factors. It is therefore recommended that cities conduct a life cycle analysis that is location-specific when making cost-based decisions on system alternatives. For more information on assumptions used to create this tool, see "STeP Market Insights for the Omni Processor" and "STeP Techno-Economic Analysis (TEA) of Model Fecal-Sludge Management and Sewer-Based Systems in India”. We would like to thank professor Srinivas Chary of the Administrative Staff College of India for his inputs to this work (www.asci.org).
0.1–1 million people, 20–40% sewage coverage, high number of septic tanks1
India City Archetype: Steady Roller
1 Analysis is based on cost comparison at a ~200K-240K fecal sludge management (FSM) reliant population equivalent. Depending on specific population needs, multiple/distributed SCWO-OP or P-OP systems may be required. Note that STeP’s “Market Insights for the Omni Processor” report indicates that decision makers may consider ease-of-operation when selecting a FSM system for this city archetype. However, this factor is not considered in the decision tree, because ease-of-operation issues are assumed to be easily addressed via training or hiring. See second page for FSM system descriptions. STP stands for sewage treatment plant, and FS stands for fecal sludge. Other acronyms are explained on the second page.
2 For example, is <2 hectares of land available for a fecal sludge treatment plant (FSTP)?
3 For example, does the land available for the FSTP cost Rs 39,400/m2 or more? Note that all remaining questions in the decision tree assume low land prices (e.g., ~Rs 3,150/m2).
4 FS-1 and FS-4 represent the lowest-cost solutions for this scenario when compost prices are less than Rs 1.5/kg.
Assumptions
Yes
Consider co-treatment: improvement of existing or planned STPs to treat
FS. Also consider G-OP for biosolids treatment.
Consider adopting FSM
Consider G-OP
Are you considering co-treatment of MSW?
Yes
Consider P-OP, SCWO-OP, or FS-4
Is water reclamation a primary driver?
Yes
Consider P-OP, SCWO-OP, or FS-4
Is land availability a constraint?2 Yes
Are land prices high?3 Consider FS-4Yes
Consider FS-2 or FS-3
Do you value the production of compost?
Yes
Do existing or planned STPs have extra
capacity to treat FS?
No
YesConsider P-OP or
SCWO-OP
Do you value complete pathogen destruction in solids produced by
your FSTP?
ConsiderFS-1 or FS-44
No
No
No
No
No
No
Model system: SCWO-OP, or Supercritical Water Oxidation Omni-Processor*
Fecalsludge
Vacuum tanker
Mechanical gritremoval
FecalsludgeVacuum tanker
Grit removal &screening
Mechanicaldewatering
Vacuum tankerManual Screen
Holding/mixing tank
Activated Sludge(Packaged)
Wash-water SCWO
Dewateredsludge
High-qualityeffluent discharge
OP Technology
Storage
Mixing Tank(Polymer)
Polymer mixingwater
Returned sludge
Salts/minerals
Distilled & hot water
Electricity
Low-grade thermal heat
LEGEND
Fecal sludgeLiquidsSolids (sludge)
Additional system inputHeat / energy
LEGEND
Fecal sludgeLiquidsSolids (sludge)Additional input
LEGEND
Fecal sludgeLiquidsSolids (sludge)Reusable co-product
Model system: P-OP, or Pyrolysis-Based Small Omni-Processor
Mechanizeddewatering
Wastewater treatment
Activated Sludge(Packaged)
Dewatered sludge
Treated liquideffluent
Biochar/Ash(reuse/landfill)
FSTP Technology
Storage
Biomass
Thermal drier
Pasteurization
Heat
Heat
Heat
Heat
LEGEND
Fecal sludgeLiquidsSolids (sludge)Additional input
Model system: G-OP, or Large Omni-Processor with Gasifier
Heat
Pyrolysis
Start-up fuel
Mechanizeddewatering
Model system: FS-3
DischargeDischarge
Landfill
Sludge Drying Bed(unplanted with roof)
Compost
Maturation Pond
Co-composting(Windrow)
Co-composting (Windrow)
Anaerobic digestion
Biogas
Aerated Pond(incl. settling pond)
Vacuum tanker Manual Screen Holding/mixing tank
LEGEND
Fecal sludgeLiquidsSolids (sludge)Reusable co-product
Model system: FS-4
LEGEND
Fecal sludgeLiquidsSolids (sludge)Reusable co-product
LEGEND
Fecal sludgeLiquidsSolids (sludge)Reusable co-product
Model system: FS-2
Vacuum tanker Manual Screen Sludge Drying Bed(unplanted with roof) Vacuum tanker Manual Screen Sludge Drying Bed
(unplanted with roof)
Discharge Discharge
Discharge
LandApply
Pond system(Anaerobic, Facultative, Maturation)
Pond system(Anaerobic, Facultative, Maturation)
Model system: FS-1
Chlorination
CleanWater
Receiving &Screening
Dewatering(Screw Press)
Sludgedrier Power
Boiler +Turbine +
Air emissionsprocess
Separationof MSW
Supernatant Treatment Process
Electricity
Driedsolids
Dewatered Solids
Liquid
Vacuum tankerFecal
sludge
OP Technology
MSW
Landfill Site
Gasifier & Process Boiler
Fuel source(start-up & Supplement)
Ash;Air emissions
Treated liquideffluent(reuse/discharge)
* Note that SCWO-OP is a future technology that is still under development.