Page 101 - Materials Chemistry, Second Edition

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72 Waste Management Practices: Municipal, Hazardous, and Industrial

TABLE 4.8
Metal Products in MSW, 1999

Product Category Generation
(thousands of tons)
Durable Goods
Ferrous metals 10,390
Aluminum 960
Lead 970
Other nonferrous metals 420
Total metals in durable goods 12,740
Nondurable Goods
Aluminum 200
Containers and Packaging
Steel
Food and other cans 2,690
Other steel packaging 240
Total steel packaging 2,930
Aluminum
Beer and soft drink cans 1,540
Food and other cans 50
Foil 380
Total aluminum packaging 1,970
Total metals in containers and packaging 4,900
Total Metals 17,840
Ferrous 13,320
Aluminum 3,130
Other nonferrous 1,390
Source: U.S. EPA, 2001.

Plastic food service items are generally made of clear or foamed polystyrene while trash bags are
made of high- or low-density polyethylene. A wide variety of other resins are used in other nondurable
goods. Plastic resins are used in container and packaging products such as polyethylene terephthalate
(PET) soft drink bottles, high-density polyethylene (HDPE) bottles for milk and water, and a wide
variety of other resin types are used in containers, bags, sacks, wraps, and lids (U.S. EPA, 2001).
Plastics are a rapidly growing segment of MSW. In 1960, plastics comprised an estimated 390,000
tons (< 1%) of MSW generation. The quantity has increased to 24.2 million tons (10.5%) in 1999.

4.4.7 RUBBER AND LEATHER
Automobile and truck tires are the predominant sources of rubber in MSW (Table 4.10). Other sources
include clothing and footwear and other durable and nondurable products. The generation of rubber and
leather in MSW has increased from 1.8 million tons in 1960 to 6.2 million tons in 1999. One reason for
the relatively slow rate of growth is that tires have been made smaller and longer-wearing than previ-
ously. As a percentage of total MSW generation, rubber and leather have remained steady at 3.0%.

4.4.8 TEXTILES
Textiles in MSW occur in discarded clothing, although other sources include furniture, carpets,
tires, footwear, and other nondurable goods such as towels. A total of 9.1 million tons of textiles
were generated in 1999, comprising 3.9% of total MSW generation.