MUNICIPAL SOLID WASTE MANAGEMENT AND DISPOSAL - Environmentally Conscious Materials Handling - page 143

4 RECYCLING MUNICIPAL SOLID WASTE

Recycling is widely regarded to be environmentally beneficial and conducive
to sustainable economic development. It saves our valuable resources, decreases
demand for landfill space and generally saves energy in avoiding raw material
extractions. Nevertheless, the collection, sorting and processing of recyclable
materials for the manufacture of new products have their own environmental
impacts. In addition, reduction in the amount of combustible substances such as
paper and cloth, as a consequence of waste classification and recycling, results
in a substantial decrease in the amount of heat generated during the course of
waste incineration, and thus increases the incineration operating cost. Although
incineration can lengthen the lifetime of landfills, the expenses are high for the
construction, operation, and maintenance of incinerators. The typical solid waste
for recycling is listed in this section.

4.1 Aluminum Cans

Because of the high price of aluminum and the aluminum industry's infrastructure
support, the aluminum beer and soft drink can is the most recycled consumer
beverage container in the United States (The Aluminum Association 2008). In
2006, 1.44 million tons of aluminum beverage cans were generated in MSW.
Out of these, 0.65 million tons, or 45 percent, were recovered and 0.79 million
tons were discarded. Used aluminum beverage can scrap is the major component
of processed old scrap, which accounts for approximately one-half of the old
aluminum scrap consumed in the United States. Due to improved production
efficiency, the weight of an individual aluminum can has been decreased, and
therefore, the number of aluminum cans produced by a pound of aluminum has
increased. Aluminum beverage cans continue to make up the largest portion
of the scrap aluminum purchased domestically. However, discarded aluminum
products (old scrap) other than used beverage containers are also a significant
source.

4.2 Paper and Paperboard

Paper and paperboard products constitute about 34 percent of the MSW stream.
This is the largest portion of MSW. In 2006, Americans generated about 85
million tons of paper products, which are nearly a threefold increase from 1960.
About 52 percent of all paper and paperboard products were recovered in 2006,
nearly two and a half times the percentage in 1960 (U.S. EPA 2007).

4.3 Corrugated Boxes

Approximately 37 percent of paper and paperboard products in MSW are
corrugated boxes. In 2006, 31.4 million tons of corrugated boxes were generated