Solid Waste Management Notes

What is Waste?

Waste is any product or substance no longer suitable for its intended use.
Source:
- University of Tartu, MOOC: Auditing waste management (Accessed December 19, 2024).
- Food Waste Index Report 2024, UN Environment Programme.
Statistics:
- 1.05 billion tonnes of waste annually.
- 132 kg/person/year.
- 783 million people suffer from hunger.
- 400 million metric tons per year.

Types of Solid Waste

Solid wastes are wastes that aren't liquid or gaseous.
- Examples: durable goods, nondurable goods, containers, packaging, food scraps, yard trimmings, and miscellaneous inorganic wastes.
Solid waste is roughly synonymous with "refuse."
Municipal Solid Waste (MSW):
- Solid waste from residential, commercial, institutional, and industrial sources.
- Excludes construction waste, automobile bodies, municipal sludge, combustion ash, and industrial process wastes.
Industrial wastes:
- Wastes arising from industrial activities.
- Includes rubbish, ashes, demolition and construction wastes, and special wastes.
Hazardous Waste:
- Wastes that pose a substantial danger to human, plant, or animal life.
- Characteristics:
  - Ignitability
  - Corrosivity
  - Reactivity
  - Toxicity
- Principal sources of hazardous biological wastes are hospitals and biological research facilities.

Solid Waste Components

Food waste:
- Animal, fruit, or vegetable residues resulting from handling, preparation, cooking, and eating.
- Putrescible, decomposes rapidly, especially in warm weather.
Rubbish:
- Combustible and noncombustible solid wastes, excluding food wastes.
- Combustible: paper, cardboard, plastics, textiles, rubber, leather, wood, furniture, and garden trimmings.
- Noncombustible: glass, crockery, tin cans, aluminum cans, ferrous and nonferrous metals, dirt, and construction wastes.
Ashes and Residues:
- Materials remaining from burning wood, coal, coke, and other combustible wastes.
- Composed of fine, powdery materials, cinders, clinkers, and small amounts of burned/partially burned materials.
Demolition and Construction Waste:
- Wastes from razed buildings and other structures (demolition wastes).
- Wastes from construction, remodeling, and repairing buildings (construction wastes).
- Includes dirt, stones, concrete, bricks, plaster, lumber, shingles, and plumbing/heating/electrical parts.
Special Waste:
- Street sweepings, roadside litter, catch-basin debris, dead animals, and abandoned vehicles.
Treatment plant waste:
- Solid and semisolid wastes from water, wastewater, and industrial-waste treatment facilities.

Solid Waste Management Flow

Generation
Storage
Collection
Transfer and Transport
Processing/Treatment
Recovery and Recycling
Disposal

Waste Generation in India

Calculated and expected population growth and national waste generation rate.
Per capita generation of MSW in selected Indian cities in 2000 and 2011.
Area of land required for unsanitary disposal of MSW generated in India.

Physical Composition of Solid Waste in India

Biodegradable Waste:
- Food and kitchen waste, green waste (vegetables, flowers, leaves, fruits), and paper.
Recyclable Material:
- Paper, glass, bottles, cans, metals, certain plastics, etc.
Inert Waste Matter:
- Construction and Demolition waste, dirt, debris.
Composite waste:
- Waste clothing, Tetra packs, waste plastics such as toys.
Domestic Hazardous Waste:
- Waste medicine, e-waste, paints, chemicals, light bulbs, fluorescent tubes, spray cans, fertilizer and pesticide containers, batteries, and shoe polish.

Physical Composition Factors

Individual Components
Density
Particle Size
Moisture Content

Density

Density, i.e., mass per unit volume $(kg/m^3)$ , is critical in designing a Solid Waste Management system.
- Examples: sanitary landfills, storage, collection types, and transport vehicles.

Moisture Content

Defined as the $ratio of the weight of water (wet weight - dry weight) to the total weight of the wet waste$ .
Increases the weight of solid wastes, thereby increasing the cost of collection and transport.
Critical determinant in the economic feasibility of waste treatment by incineration.
- Wet waste consumes energy for water evaporation and raising water vapour temperature.

Particle Size

Measurement of particle size distribution is important in designing mechanical separators and shredders.
Results are expressed as a plot of particle size $(mm)$ against $percentage less than a given value$ .

Moisture Content Calculation Example

Based on a $100 kg$ sample of waste.
Components, Percent by mass, Moisture Content (%)
- Food wastes: 15, 70
- Paper: 45, 6
- Cardboard: 10, 5
- Plastics: 10, 2
- Garden trimmings: 10, 60
- Wood: 5, 20
- Tin Cans: 5, 3
Dry mass (kg):
- Food wastes: $4.5$
- Paper: $42.3$
- Cardboard: $9.5$
- Plastics: $9.8$
- Garden trimmings: $4.0$
- Wood: $4.0$
- Tin Cans: $4.9$
Total dry mass: $79.0 kg$
$Moisture Content = { (100 - 79) / 100 } * 100 = 21\%$

Density Calculation Example

Based on a $1000 kg$ sample of waste.
Components, Percent by mass, Typical density $(kg/m^3)$
- Food wastes: 15, 290
- Paper: 45, 85
- Cardboard: 10, 50
- Plastics: 10, 65
- Garden trimmings: 10, 105
- Wood: 5, 240
- Tin Cans: 5, 90
Volume $(m^3)$
- Food wastes: $0.52$
- Paper: $5.29$
- Cardboard: $2.00$
- Plastics: $1.54$
- Garden trimmings: $0.95$
- Wood: $0.21$
- Tin Cans: $0.56$
Total Volume: $11.07 m^3$
$Density = 1000 / 11.07 = 90.33 kg/m^3$

Chemical Composition of Solid Waste

Important in evaluating alternative processing and energy recovery options.
Proximate Analysis:
- Moisture (Loss at $105^oC$ for $24 h$ ).
- Volatile matter (additional loss on ignition at $550^oC$ for $1-2 h$ ).
- Ash: Residue after burning.
- Fixed Carbon $= VS \%/1.8$
Ultimate Analysis: Percent of Carbon $(C)$ , Hydrogen $(H)$ , Nitrogen $(N)$ , Sulfur $(S)$ , Oxygen $(O)$
Heating value (Calorific Value)

Volatile Solid Determination

Weigh the empty crucible.
Weigh the dried and/or sieved sample.
Heat the sample in a furnace at $550^oC$ for $2 h$ .
Note the final weight of the sample and calculate the VS.

Assignment Questions

Describe the principle and functioning of Bomb Calorimeter.
What is the waste composition and waste generation rate of your city?

What is Waste?

Waste is any product or substance no longer suitable for its intended use.
Source:- University of Tartu, MOOC: Auditing waste management (Accessed December 19, 2024).
- Food Waste Index Report 2024, UN Environment Programme.

Types of Solid Waste

Solid wastes are wastes that aren't liquid or gaseous.- Examples: durable goods, nondurable goods, containers, packaging, food scraps, yard trimmings, and miscellaneous inorganic wastes.
Solid waste is roughly synonymous with "refuse."
Municipal Solid Waste (MSW):- Solid waste from residential, commercial, institutional, and industrial sources.
- Excludes construction waste, automobile bodies, municipal sludge, combustion ash, and industrial process wastes.
Industrial wastes:- Wastes arising from industrial activities.
- Includes rubbish, ashes, demolition and construction wastes, and special wastes.
Hazardous Waste:- Wastes that pose a substantial danger to human, plant, or animal life.
- Characteristics:- Ignitability
  - Corrosivity
  - Reactivity
  - Toxicity
- Principal sources of hazardous biological wastes are hospitals and biological research facilities.

Solid Waste Components

Food waste:- Animal, fruit, or vegetable residues resulting from handling, preparation, cooking, and eating.
- Putrescible, decomposes rapidly, especially in warm weather.
Rubbish:- Combustible and noncombustible solid wastes, excluding food wastes.
- Combustible: paper, cardboard, plastics, textiles, rubber, leather, wood, furniture, and garden trimmings.
- Noncombustible: glass, crockery, tin cans, aluminum cans, ferrous and nonferrous metals, dirt, and construction wastes.
Ashes and Residues:- Materials remaining from burning wood, coal, coke, and other combustible wastes.
- Composed of fine, powdery materials, cinders, clinkers, and small amounts of burned/partially burned materials.
Demolition and Construction Waste:- Wastes from razed buildings and other structures (demolition wastes).
- Wastes from construction, remodeling, and repairing buildings (construction wastes).
- Includes dirt, stones, concrete, bricks, plaster, lumber, shingles, and plumbing/heating/electrical parts.
Special Waste:- Street sweepings, roadside litter, catch-basin debris, dead animals, and abandoned vehicles.
Treatment plant waste:- Solid and semisolid wastes from water, wastewater, and industrial-waste treatment facilities.

Solid Waste Management Flow

Generation
Storage
Collection
Transfer and Transport
Processing/Treatment
Recovery and Recycling
Disposal

Waste Generation in India

Calculated and expected population growth and national waste generation rate.
Per capita generation of MSW in selected Indian cities in 2000 and 2011.
Area of land required for unsanitary disposal of MSW generated in India.

Physical Composition of Solid Waste in India

Biodegradable Waste:- Food and kitchen waste, green waste (vegetables, flowers, leaves, fruits), and paper.
Recyclable Material:- Paper, glass, bottles, cans, metals, certain plastics, etc.
Inert Waste Matter:- Construction and Demolition waste, dirt, debris.
Composite waste:- Waste clothing, Tetra packs, waste plastics such as toys.
Domestic Hazardous Waste:- Waste medicine, e-waste, paints, chemicals, light bulbs, fluorescent tubes, spray cans, fertilizer and pesticide containers, batteries, and shoe polish.

Physical Composition Factors

Individual Components
Density
Particle Size
Moisture Content

Density

Density, i.e., mass per unit volume $(kg/m^3)$ , is critical in designing a Solid Waste Management system.- Examples: sanitary landfills, storage, collection types, and transport vehicles.

Moisture Content

Defined as the $ratio of the weight of water (wet weight - dry weight) to the total weight of the wet waste$ .
Increases the weight of solid wastes, thereby increasing the cost of collection and transport.
Critical determinant in the economic feasibility of waste treatment by incineration.- Wet waste consumes energy for water evaporation and raising water vapour temperature.

Particle Size

Measurement of particle size distribution is important in designing mechanical separators and shredders.
Results are expressed as a plot of particle size $(mm)$ against $percentage less than a given value$ .

Moisture Content Calculation Example

Based on a $100 kg$ sample of waste.
Components, Percent by mass, Moisture Content (%)- Food wastes: 15, 70
- Paper: 45, 6
- Cardboard: 10, 5
- Plastics: 10, 2
- Garden trimmings: 10, 60
- Wood: 5, 20
- Tin Cans: 5, 3
Dry mass (kg):- Food wastes: $4.5$
- Paper: $42.3$
- Cardboard: $9.5$
- Plastics: $9.8$
- Garden trimmings: $4.0$
- Wood: $4.0$
- Tin Cans: $4.9$
Total dry mass: $79.0 kg$
$Moisture Content = { (100 - 79) / 100 } * 100 = 21\%$

Density Calculation Example

Based on a $1000 kg$ sample of waste.
Components, Percent by mass, Typical density $(kg/m^3)$ - Food wastes: 15, 290
- Paper: 45, 85
- Cardboard: 10, 50
- Plastics: 10, 65
- Garden trimmings: 10, 105
- Wood: 5, 240
- Tin Cans: 5, 90
Volume $(m^3)$ - Food wastes: $0.52$
- Paper: $5.29$
- Cardboard: $2.00$
- Plastics: $1.54$
- Garden trimmings: $0.95$
- Wood: $0.21$
- Tin Cans: $0.56$
Total Volume: $11.07 m^3$
$Density = 1000 / 11.07 = 90.33 kg/m^3$

Chemical Composition of Solid Waste

Important in evaluating alternative processing and energy recovery options.
Proximate Analysis:- Moisture (Loss at $105^oC$ for $24 h$ ).
- Volatile matter (additional loss on ignition at $550^oC$ for $1-2 h$ ).
- Ash: Residue after burning.
- Fixed Carbon $= VS \%/1.8$
Ultimate Analysis: Percent of Carbon $(C)$ , Hydrogen $(H)$ , Nitrogen $(N)$ , Sulfur $(S)$ , Oxygen $(O)$
Heating value (Calorific Value)

Volatile Solid Determination

Weigh the empty crucible.
Weigh the dried and/or sieved sample.
Heat the sample in a furnace at $550^oC$ for $2 h$ .
Note the final weight of the sample and calculate the VS.