What Happens to Recycled Materials?
For more than 30 years, the U.S. Environmental Protection Agency (EPA) has collected data on waste generation and disposal in the United States. The available data (current through 2008) shows that Americans recycled and composted 83 million out of 250 million tons of trash.-
Considerations
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In an affluent society, there is a tendency to throw away used materials because of the availability and abundance of cheap raw materials. Recycling becomes economically feasible when the cost of recycling is less than the cost of processing raw materials.
Types
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There are two types of recycling operations: external and internal. External recycling is a process where materials are reclaimed from a product that has been used or rendered obsolete. For example, beverage cans, old newspapers and magazines, and glass bottles are materials that are externally recycled. These materials are collected through buy-back centers, drop-off centers and curbside collection. Internal recycling is the reuse of the waste product of a manufacturing process. This type of recycling is common in the metals industry. Metal cuttings and imperfect products are remelted, recast and redrawn within the steel mill.
What Happens to Recycled Materials?
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Bark wood, pulp mills, paper mills: returned to the earth as fertilizers and soil conditioners.
Battery plates: melted to produce an alloy for use in manufacturing new batteries or pure lead products
Beverage cans: remelted for recycled aluminum.
Carburetors and electrical components: rebuilt and resold
Domestic wastewater: goes to a sewage treatment plant where it is purified and recycled to the household
Glass: cullet (broken or refuse glass) is currently used in new-glass production
Industrial wastewater: funneled back to streams, rivers and oceans for recycling by nature or processed in a treatment plant
Newsprint and cardboard: repulped to make the same materials
Organic waste: decomposed and turned into humus, soil fertilizer
Polyurethane: shredded for use as fillers or insulating materials
Scrap Metal: smelted and recast. A by-product produced by smelting called coke produces ammonia
Scrap paper: repulped for low-quality paper such as boxboard, tissues and towels.
Sludges: from pulp and paper manufacture and phosphate slime from fertilizer manufacture, are made into gypsum wallboard
Thermoplastics: remelted and reformed into new products
Significance
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Overall, the benefits gained from recycling are cleaner land, air, and water, better health and a more sustainable economy. Recycling reduces the solid waste deposited in landfills, which have become expensive. And finally, recycled materials replace the use of increasingly scarce natural resources such as petroleum, natural gas, coal, mineral ores and trees.
Facts
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Paper accounts for more than one-third of the weight of all the material deposited in landfills in the United States. Glass makes up about 6 percent by weight of the material in municipal waste streams.
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