Chapter 10: Waste Management

Question 1

What is the current emphasis in Waste Management?

Answer 1

Avoiding landfilling and using incinerators to generate steam and electricity.

Question 2

What is MSW and how much is used in Combustion?

Answer 2

Municipal Solid Waste.
About 15% is used in combustion.

Question 3

What is WTE?

Answer 3

Waste To Energy.
Refers to any waste treament that creates energy

Question 4

What is HHV?

Answer 4

Higher Heat Value.

• Complete combustion
• measures rise in temperature in bath of water
• Includes energy used to vapourize moisture

Question 5

What is LHV?

Answer 5

Lower Heat Value.

• Recoverable energy from combustion

Question 6

What heat is usually lost to atmosphere?

Answer 6

Latent Heat

Question 7

What are the 2 sources of water vapour in waste?

Answer 7

• Moisture
• Hydrogen reacting with oxygen to form water

Question 8

What materials are examples of HHV’s?

Answer 8

• paper
• plastic
• food waste
• yard waste

Question 9

What are some Emissions from incineration?

Answer 9

• Chlorinated Compounds
• Heavy Metals

Question 10

What is Collected Ash?

Answer 10

Toxic materials from incineration that often cannot be disposed of in a landfill.

Question 11

What are favourable attributes of WTE Incineration?

Answer 11

• Volume reduction
• immediate disposal
• less land requirement
• energy recovery

Question 12

What are unfavourable attributes of WTE Incineration?

Answer 12

• potential release of toxic substances
• potential hazardous ash recovery
• public perception

Question 13

What are 3 components of a Landfill?

Answer 13

• Cells: each day’s waste received and compacted
• Daily Cover: cover of cells with thin layer of soil
• Lifts: active area consisting of multiple cells

Question 14

What 2 things does the sizing of landfill depend on?

Answer 14

• Rates of disposal
• Density of wastes when compacted

Question 15

What are 4 processes that occur during degredation?

Answer 15

1. Organic matter is stabilized
2. Leachate Production
3. Landfill gas generation
4. Settlement

Question 16

What are the 4 phases of Decomposition?

Answer 16

1. Aerobic
2. Acid
3. Methanogenesis
4. Methanogenesis Steady

Question 17

What is Leachate?

Answer 17

Water flowing through the solid waste. Contains dissolved contaminants.

Question 18

What are 2 gases collected in landfills?

Answer 18

Methane and CO2

Question 19

Does Methane or CO2 have a higher greenouse gas potential?

Answer 19

Methane

Question 20

What mechanisms cause large settlements in a landfill?

Answer 20

• Mechanical/Primary Compression
• Biodegredation
• Physical creep compression

Question 21

What mechanisms cause small settlements in a landfill?

Answer 21

• Physical-chemical/corrosion
• Interaction (combustion)
• Consolidation (squeezing water from pore spaces)

Question 22

What are some accepted materials at a landfill?

Answer 22

• Wood
• soft materials
• Roofing materials
• yard trimmings

Question 23

What are non-accepted materials at a landfill?

Answer 23

• treated wood
• recyclable material
• hazardous waste
• household garbage

Question 24

Are you feeling tired yet?