Pre-cycling
• Not allowing something to be wasted
• Could involve reuse or simply using something wisely as to not allow it to become trash
Composting
• Sweet-smelling, dark brown humus-like material that is rich in organic matter and soil nutrients
Composting
• Advantages• Could reduce up to 35%
of waste• Can be used as fertilizer
or landfill cover• Helps rebuild eroded soil
• Disadvantages• Excludes toxic materials• Odor (enclosed facility;
near landfill; or be careful to get only biodegradable waste and put in closed container with air circulation
• Can be expensive to set up
Primary Recycling
• Also called closed-loop recycling
• Recycles the same product
• Aluminum cans form new aluminum cans
• Newspaper becomes newspaper
Secondary Recycling
• Also called Open Loop Recycling
• Waste is converted to new products
• Jeans into carpet
• Plastic into lumber
Plastics Recycled
• What % of plastics do you think get recycled?
• About 5% of plastics are recycled
• Why?
• Low cost resin except for the drinking bottle which is most likely type of plastic to be recycled
Post-consumer recycling
• Waste that could have been put into a landfill because it had been already used for its original purpose but was instead recycled into either the same product or a different product that its original use
Pre-consumer Recycling
• Material was not used for its original purpose. In the manufacturing process this material was excess and did not make it into the original product; therefore, the manufacturer recycled it back into its own manufacturing process
• Can you think of an example of this?
How is recycling done?
• Centralized recovery areas are where mixed urban waste is transported to this type of facility
• Recovery implies recycling
• Rest of the waste is burned
• There are roughly 250 of these facilities in the US
What factors limit recycling?
• The environmental cost is not included in the purchase price
• Tax breaks for manufacturers but not for individual recyclers
• Lack of market for recycled materials
Traditional waste management
• Trash is presorted into recyclables and trash
• Recyclables go one route
• Trash is taken to sanitary landfill
Land Disposal
• 57% of waste goes to a landfill
• Sanitary Landfill: garbage graveyard where solid waste is spread out in thin layers and compacted daily with fresh layers of clay or plastic foam
Landfill Liners
• Landfills need to have thick layer of concrete separating them from the nearby material
• The concrete layer is covered over with a thick liner which is thicker than the shingles on your roof
Incineration
• 7-15% of US waste is incinerated
• Process by which combustible waste is burned and ash is buried
Incineration
• Advantages• Reduces waste• Most things are
combustible• Cheap once set up
• Disadvantages• Fire and associated
threat of explosive substances getting into incinerator
• Separation of items• Expense of incinerator• Air pollution• Smoke
Detoxification
• Some waste can be disposed of in other ways if it was detoxified.
• This can be done by toxic-degrading bacteria • Also substances can be watered down • Finally, some substances like heavy metals
cannot be dealt with in this way • Heavy metal poisoning is very difficult to manage
b/c body’s tissues pick up the metal and is not easily removed