41 Solid Waste Management
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Transcript of 41 Solid Waste Management
SOLID WASTE SOLID WASTE MANAGEMENTMANAGEMENT
CE 102CE 102
DEFINITIONDEFINITION
•Solid wastes comprise all the wastes arising from human and animal activities that are normally solidand that are discarded as useless or unwanted. •Solid waste management may be defined as thediscipline associated with the control of generation, storage, collection ,transfer and transport ,processing, and disposal of wastes in amanner that is in accord with the best principles of public health, economics, engineering,conservations.
Functional elements of solid waste Functional elements of solid waste Management systemManagement system
Waste generation
Waste handling,separationStorage and processing at the source
Collection
Disposal
Transfer and transportSegregation & Processing &
Transformation of solidwaste
Small townsSmall towns 100g/p/day100g/p/day Medium townsMedium towns 300-400g/p/day300-400g/p/day Large townsLarge towns 500g/p/day500g/p/day
In general varies between 0.3-0.6 kg/p/dayIn general varies between 0.3-0.6 kg/p/day
Characteristics of Municipal Solid Waste Characteristics of Municipal Solid Waste Generated by Metro CitiesGenerated by Metro Cities
Sl. No.
Metro city Paper Textile Leather Plastic Metal Glass Ash, Fine
earth & others
Compostable matter
1 Mumbai 10.0 3.6 0.2 2.0 - 0.2 44.0 40.0
2 Delhi 6.6 4.0 0.6 1.5 2.5 1.2 51.5 31.78
3 Hyderabad 7.0 1.7 - 1.3 - - 50.0 40.0
4 Jaipur 6.0 2.0 - 1.0 - 2.0 47.0 42.0
5 Kanpur 5.0 1.0 5.0 1.5 - - 52.5 40.0
6 Chennai 10.0 5.0 5.0 3.0 - - 33.0 44.0
7 Visakhapatnam
3.0 2.0 - 5.0 - 5.0 50.0 35.0
Characteristics ( Percent by wt. )
Characteristics of the wasteCharacteristics of the waste PhysicalPhysicalCompositionCompositionDensityDensityMoisture contentMoisture content
Composition of WasteComposition of Waste
Chemical
CarbonVOCAsh contentNitrogenPhosphate•Calorific value
TYPES OF SOLID WASTESTYPES OF SOLID WASTES
Based on the source of generationBased on the source of generation Residential wastesResidential wastes
• Commercial wastesCommercial wastes• Institutional wastesInstitutional wastes• Construction and demolition wastesConstruction and demolition wastes• Municipal services Municipal services • Treatment plant wastesTreatment plant wastes• Industrial wastesIndustrial wastes• Agricultural wastesAgricultural wastes
Based on decomposabilityBased on decomposability
• Non-decomposible Non-decomposible • Decomposible wasteDecomposible waste
Based on combustibilityBased on combustibility
• Combustible wasteCombustible waste• Non-combustible wasteNon-combustible waste
Based on the contents of the wasteBased on the contents of the waste RubbishRubbish Food wasteFood waste AshesAshes Dead animalsDead animals Treatment plant wasteTreatment plant waste Industrial wasteIndustrial waste Mining wasteMining waste
Collection systemCollection system Low rise buildingsLow rise buildings
CurbCurb AlleyAlley Setout-setbackSetout-setback SetoutSetout Backyard carryBackyard carry
High rise buildings—High rise buildings— Crew can collect wasteCrew can collect waste Waste taken to service area by tenantsWaste taken to service area by tenants Tenants putting the waste in chuteTenants putting the waste in chute
Types of Collection systemTypes of Collection system
Haul container system (HCS)Haul container system (HCS) Stationary container system (SCS)Stationary container system (SCS)
Transportation systemTransportation system
Motor vehicleMotor vehicle RailwaysRailways HydraulicHydraulic PneumaticPneumatic Compressed air/vacuumCompressed air/vacuum
Need of TSNeed of TS
Illegal dumpsIllegal dumpsdisposal site too fardisposal site too farSmall capacity collection truckSmall capacity collection truckLow density areaLow density areaMore waste to large distanceMore waste to large distance
PROCESSING OF WASTESPROCESSING OF WASTES
SegregationSegregation
CompactionCompaction
ShreddingShredding
To reduce the volume and quantity
Bioconversion
BiomethanationBiomethanation
CompostingComposting ConventionalConventional vermicompostingvermicomposting
CompostingComposting
Biological transformation of the waste.Biological transformation of the waste. Transformation of biodegradable waste into Transformation of biodegradable waste into
biologically stable matter using micro organisms.biologically stable matter using micro organisms. Reduces the volume of waste.Reduces the volume of waste. Destroy pathogens/insects.Destroy pathogens/insects. End product is a humus like material called compost End product is a humus like material called compost
that is rich in nutrients.that is rich in nutrients. Compost can be used to support plant growth and as a Compost can be used to support plant growth and as a
soil amendmentsoil amendment..
In the Principle of Microbial Infallibility, it is assumed that all organic materials can be biodegraded, given proper biological, chemical and physical conditions. The provision of these conditions requires that bio-systems be engineered to create an environment conducive to a substrate's biological utilization.
1. Oxygen and Aeration2. Organisms3. C:N Ratio4. Moisture5. Particle Size6. Temperature7. Time
Factors Affecting the Composting Process
Worms
Eudrilus eugineae
Eisena foetida
Vermicomposting
• Combustion processCombustion process
Thermal processing of solid waste by chemical oxidation Thermal processing of solid waste by chemical oxidation with stoichiometric or excess amounts of air.with stoichiometric or excess amounts of air.
End products-hot gases, water vapour (flue gas), and non-End products-hot gases, water vapour (flue gas), and non-combustible residue (ash).combustible residue (ash).
Energy can be recovered by heat exchange from the hot Energy can be recovered by heat exchange from the hot combustion gases. combustion gases.
Incineration
PyrolysisPyrolysis
Thermal processing of waste in the complete absence Thermal processing of waste in the complete absence of air.of air.
End products-solids (char), liquids (tar/oil) and gases End products-solids (char), liquids (tar/oil) and gases (hydrogen. methane, carbon monoxide, carbon (hydrogen. methane, carbon monoxide, carbon dioxide etc.)dioxide etc.)
Endothermic process, external source of heat is Endothermic process, external source of heat is required.required.
GasificationGasification
Process of partial combustion of solid waste in which Process of partial combustion of solid waste in which air is supplied less than stoichiometric air.air is supplied less than stoichiometric air.
End products-Flue gases( carbon monoxide, End products-Flue gases( carbon monoxide, hydrogen, carbon dioxide, hydrocarbons (methane)), hydrogen, carbon dioxide, hydrocarbons (methane)), condensible liquids, solid residue (char).condensible liquids, solid residue (char).
Energy efficient technique for reducing the volume of Energy efficient technique for reducing the volume of solid waste and the recovery of energy.solid waste and the recovery of energy.
The gas generated can be used to generate electricity The gas generated can be used to generate electricity using gas turbines or can be used in boilers as fuel.using gas turbines or can be used in boilers as fuel.
DISPOSALDISPOSAL Open dumpingOpen dumping
Land fillingLand filling
Disposal of residual solid wastes in the surface soils Disposal of residual solid wastes in the surface soils of the earth.of the earth.
Barging in to seaBarging in to sea
Feeding to hogsFeeding to hogs
LANDFILLLANDFILL
Primary means of MSW disposalPrimary means of MSW disposal
Disposal of residual solid wastes in the surface Disposal of residual solid wastes in the surface soils of the earth.soils of the earth.
CLASSIFICATIONCLASSIFICATION
1.1. Secure landfills /Class 1 landfillsSecure landfills /Class 1 landfills Designed to handle hazardous wastesDesigned to handle hazardous wastes..
2.2. Monofills /Class 2 landfillsMonofills /Class 2 landfills Designed to handle particular types of wastes Designed to handle particular types of wastes
such as incinerator ash or sewage sludge that such as incinerator ash or sewage sludge that are relatively uniform in characteristics and are relatively uniform in characteristics and require special handling.require special handling.
3.3. Sanitary landfills /Class 3 landfillsSanitary landfills /Class 3 landfills Engineered facilities designed to handle Engineered facilities designed to handle
MSWMSW..
TemporaryHolding area
Environmentalmonitoring facilities
Equipmentworkshop
Inspection/Screening facility
Weighingscale
Accessroad
Leachatetreatmentfacility
Gasflaringfacility
Surfacewatercollectionfacility
Typical Layout of a Landfill
Completed fill
Active filling area
Future fill area
Stock piled cover material
Office
Landfill Cell
Cell liner
Postclosure carePostclosure care Activities associated with the long-term monitoring Activities associated with the long-term monitoring
and maintenance of the landfill (typically 30-50 and maintenance of the landfill (typically 30-50 years).years).
Dump truck
Landfill operation
Facility on restored landfill
Example Estimating Landfill Example Estimating Landfill RequirementsRequirements
Estimate the landfill area needed to handle one year’s MSW for Estimate the landfill area needed to handle one year’s MSW for a town of 100,000 people. Assume national average discards, no a town of 100,000 people. Assume national average discards, no combustion, a landfill density of 600 kg/m³, and a single 3m lift. combustion, a landfill density of 600 kg/m³, and a single 3m lift. Assume that 20 percent of the cell volume is soil used for cover.Assume that 20 percent of the cell volume is soil used for cover.
Solution:Solution: United States discards 146.6 million tonnes of MSW per year. If United States discards 146.6 million tonnes of MSW per year. If
we assume a population of roughly 260 million, the landfill we assume a population of roughly 260 million, the landfill volume of refuse for 100,000 people would be volume of refuse for 100,000 people would be
Vmsw = (146.6×10^6 tonne ×10³ kg/tonne × Vmsw = (146.6×10^6 tonne ×10³ kg/tonne × 100000people)100000people)
260 × 10^6 people × 600 kg/m³
= 93,975 m³Since only 80 percent of a cell is landfill, the volume of cell needed is
Vcell = 93,975 m³ / 0.8 = 117,468 m³
The area of lift, at 3m cell depth isThe area of lift, at 3m cell depth is A = 117,468/3 = 39,155 m²A = 117,468/3 = 39,155 m² The actual sizing of a landfill would include a number The actual sizing of a landfill would include a number
of additional factors, such as additional area of additional factors, such as additional area requirements for access roads and auxiliary facilities, requirements for access roads and auxiliary facilities, reduction in landfill volume as biological reduction in landfill volume as biological decomposition takes place and increases in decomposition takes place and increases in compaction as additional lifts are added.compaction as additional lifts are added.
Biological Reactions in LandfillsBiological Reactions in Landfills
Four stage processFour stage process
1.1. Aerobic PhaseAerobic Phase
2.2. Acid PhaseAcid Phase
3.3. Methanogenesis, unsteadyMethanogenesis, unsteady
4.4. Methanogenesis, steadyMethanogenesis, steady
Another way of studying the solid waste management is the 3R principle
INTEGRATED SOLID WASTE MANAGEMENTINTEGRATED SOLID WASTE MANAGEMENT
Selection and application of suitable techniques, Selection and application of suitable techniques, technologies and management programs to achieve technologies and management programs to achieve specific waste management objectives and goals.specific waste management objectives and goals.
3 R’s in waste management3 R’s in waste management ReduceReduce RecycleRecycle ReuseReuse
Why reduction and recycling?Why reduction and recycling? To reduce the waste to burryTo reduce the waste to burry To reduce the pollution by reusing the resources.To reduce the pollution by reusing the resources. To reduce the rate of consumption of resourcesTo reduce the rate of consumption of resources
The waste has three valuesThe waste has three values* The bulk value* The bulk value*The food value or nutrition value*The food value or nutrition value*The energy value*The energy value
RecycleRecycle Biodegradable wasteBiodegradable waste
Bio-methanationBio-methanation Composting Composting