PH 335 Unit 2| QUESTIONS WITH VERIFIED ANSWERS 100% SOLVED| LATEST UPDATE
GUARANTEED PASS
EPA's Hierarchy for Management of MSW From more favored to less favored
1.) Source Reduction (Reduce !)
2.) Reuse
3.) Recycling/composting
4.) Energy recovery
5.) Treatment and disposal / landfill
Source Reduction - "Reducing waste at the source"
- Environmentally preferred strategy
** most preferred strategy for waste reduction **
Components of source reduction
- Waste reduction
- Aims to reduce the amount of waste produced at the source
- Waste recycling
- Refers to reuse of materials in the waste
Recycling - EPA definition: process of "collecting and reprocessing a resource so it can be
used again (recycling of aluminum cans, paper, and bottles, etc.)"
Advantages of recycling:
- Reduces emissions of greenhouse gases
,- Prevents pollution generated by use of new materials
- Decreases amount of materials shipped to landfills
- Preserves natural resources
- Opens up new manufacturing employment opportunities
- Saves energy
Composting - The aerobic biological decomposition of organic materials [e.g., leaves, grass,
and food scraps] to produce a stable humus-like product
-Biodegradation is a natural, ongoing biological process that is a common occurrence in both
human-made and natural environments
- Produces a useful material that resembles soil and that can be used in gardening
Composting success
- The state of California has one of the most successful composting programs in the US
- required by law to separate their food waste from other waste (plan to reduce organic waste
to landfills by 75%)
Landfill design Least desirable option for waste
- A landfill is composed of four major parts
- Bottom liner
- System for collecting Leachates (contaminated liquid from solid waste disposal site)
- Cover
- Appropriate location that minimizes the contamination of groundwater by materials released
from the site
How a landfill works
,- The bottom is lined with a dense layer of clay and sealed with thick plastic sheeting to contain
leaks of hazardous materials.
- A flexible membrane liner holds in toxic chemicals that might contaminate groundwater.
- A leachate sump collects leachates, which then can be subjected to further treatment.
- Garbage is piled up in rows; bulldozers and rollers compact the garbage; at the end of the day,
the newly added garbage is covered with soil and other materials.
- After the garbage is covered, anaerobic bacteria aid in the decomposition of organic materials
and produce methane gas
Dangers associated with landfills
- Air pollution and groundwater contamination
- Leachates may include: Toxic heavy metals, Solvents, and cleaning agents
- Gases such as methane
Gaseous Emissions from Landfills
1. Methane, volatile organic compounds (VOCs), and other gases
- Methane vented from landfills poses a fire hazard and is a greenhouse gas.
2. VOC emissions
- Potentially carcinogenic
- May cause complaints about odors and symptoms of respiratory irritation
Megafills - Take in 5,000-10,000 tons of trash per day and serve regional needs for waste
disposal
- Tend to be more cost effective than incinerators for disposal of solid waste
federal landfill standards - Location restrictions
- Composite liners requirements
, - Leachate collection and removal systems
- Groundwater monitoring requirements
- Closure and postclosure care requirements
- Operating practices
- Corrective action provisions
- Financial assurance
incineration waste to energy
- La Cross county uses incineration of waste to generate energy
- Can be used to generate energy while reducing the volume and weight of waste
- No attempt is made to separate trash into components.
- At the high temperatures, glass and aluminum in the trash melt.
- Metals from the residues of combustion can be recycled into scrap metal.
- Remaining ash deposited in landfills
Disadvantages of incineration
- Emissions may be potentially hazardous to human health and the environment.
- Toxic materials emitted may cause air pollution or be deposited on the land or in water runoff
Disposal of Hazardous Materials and Wastes - Hazardous wastes are disposed of legally in
the US by:
- Discarding them on the surface of the land
- Storing them in slurry ponds
- Dumping them into landfills or into the ocean
- Incineration
GUARANTEED PASS
EPA's Hierarchy for Management of MSW From more favored to less favored
1.) Source Reduction (Reduce !)
2.) Reuse
3.) Recycling/composting
4.) Energy recovery
5.) Treatment and disposal / landfill
Source Reduction - "Reducing waste at the source"
- Environmentally preferred strategy
** most preferred strategy for waste reduction **
Components of source reduction
- Waste reduction
- Aims to reduce the amount of waste produced at the source
- Waste recycling
- Refers to reuse of materials in the waste
Recycling - EPA definition: process of "collecting and reprocessing a resource so it can be
used again (recycling of aluminum cans, paper, and bottles, etc.)"
Advantages of recycling:
- Reduces emissions of greenhouse gases
,- Prevents pollution generated by use of new materials
- Decreases amount of materials shipped to landfills
- Preserves natural resources
- Opens up new manufacturing employment opportunities
- Saves energy
Composting - The aerobic biological decomposition of organic materials [e.g., leaves, grass,
and food scraps] to produce a stable humus-like product
-Biodegradation is a natural, ongoing biological process that is a common occurrence in both
human-made and natural environments
- Produces a useful material that resembles soil and that can be used in gardening
Composting success
- The state of California has one of the most successful composting programs in the US
- required by law to separate their food waste from other waste (plan to reduce organic waste
to landfills by 75%)
Landfill design Least desirable option for waste
- A landfill is composed of four major parts
- Bottom liner
- System for collecting Leachates (contaminated liquid from solid waste disposal site)
- Cover
- Appropriate location that minimizes the contamination of groundwater by materials released
from the site
How a landfill works
,- The bottom is lined with a dense layer of clay and sealed with thick plastic sheeting to contain
leaks of hazardous materials.
- A flexible membrane liner holds in toxic chemicals that might contaminate groundwater.
- A leachate sump collects leachates, which then can be subjected to further treatment.
- Garbage is piled up in rows; bulldozers and rollers compact the garbage; at the end of the day,
the newly added garbage is covered with soil and other materials.
- After the garbage is covered, anaerobic bacteria aid in the decomposition of organic materials
and produce methane gas
Dangers associated with landfills
- Air pollution and groundwater contamination
- Leachates may include: Toxic heavy metals, Solvents, and cleaning agents
- Gases such as methane
Gaseous Emissions from Landfills
1. Methane, volatile organic compounds (VOCs), and other gases
- Methane vented from landfills poses a fire hazard and is a greenhouse gas.
2. VOC emissions
- Potentially carcinogenic
- May cause complaints about odors and symptoms of respiratory irritation
Megafills - Take in 5,000-10,000 tons of trash per day and serve regional needs for waste
disposal
- Tend to be more cost effective than incinerators for disposal of solid waste
federal landfill standards - Location restrictions
- Composite liners requirements
, - Leachate collection and removal systems
- Groundwater monitoring requirements
- Closure and postclosure care requirements
- Operating practices
- Corrective action provisions
- Financial assurance
incineration waste to energy
- La Cross county uses incineration of waste to generate energy
- Can be used to generate energy while reducing the volume and weight of waste
- No attempt is made to separate trash into components.
- At the high temperatures, glass and aluminum in the trash melt.
- Metals from the residues of combustion can be recycled into scrap metal.
- Remaining ash deposited in landfills
Disadvantages of incineration
- Emissions may be potentially hazardous to human health and the environment.
- Toxic materials emitted may cause air pollution or be deposited on the land or in water runoff
Disposal of Hazardous Materials and Wastes - Hazardous wastes are disposed of legally in
the US by:
- Discarding them on the surface of the land
- Storing them in slurry ponds
- Dumping them into landfills or into the ocean
- Incineration
