1060 RECYCLING WASTE MATERIALS
the U.S. Japan recycles about 50% of its paper and expects
to reach 55% by 1995.
The US EPA estimates that as much as 40% of the munic-
ipal solid waste stream is composed of paper and related
fiber products. Fluctuations in supply and demand are seri-
ous obstacles to paper recycling. This is particularly true in
areas which are near pulp producing regions. Once news-
print brought $20 per ton. Now many municipalities must
pay for disposal and frequently it is hauled to landfills.
Proposed legislation will mandate that recycled paper
make up a portion of the product mix. If enacted, demand
will more closely correspond to supply. The U.S., at the
beginning of the 90’s, is the world’s largest exporter of
wastepaper.
There is a growing demand for better grades of recycled
paper. Washing techniques for ink removal from paper are
quite water use intensive and remove only ink particles larger
than 30 micrometers. Flotation, on the other hand, removes
about 85% of particles smaller than 30 micrometers and
uses only half the water. Surfactants added to the bath aid in
producing a cleaner pulp. Flotation produces a cleaner end
product and reduces the amount of resulting waste sludge
for disposal. There is a move towards surfactant producers to
formulate products for a recycler’s specific needs.
Magazines, in the past, were difficult to recycle. Coated
paper in magazines had much more calcium carbonate or
clay filler and less wood pulp than did newsprint or other
paper grades. It has been found that filler makes it easier to
separate ink from fiber in a flotation process. Some recyclers
find it advantageous to add “old mixed grade” (OMG) to thenew material entering a pulping system. It is estimated that,
on the basis of 30% OMG and 70% newsprint, the recover-
able supply of OMG could be exceeded by the end of the
90’s. One new process shows promise of elimination of the
deinking step by application of 400 psi steam at 400°F to
newsprint.
Metals have been reclaimed on a regular basis from
industrial sources. Now a significant source of scrap metal
is municipal solid waste. The recovery rate for aluminum
is about 60%. Typically, recycled metal is remelted, along
with virgin ore, in furnaces similar to those used in metal
production. The focus in metal recycling is on separation
techniques and not on new smelting technology.
The Resource Conservation and Recovery Act (RCRA)
will be reauthorized in 1991 and the final form of this Act
will determine which wastes will be acceptable for repro-
cessing. One difficult question to be addressed is, “what is
true recycling and what is disposal disguised as recycling?”
There is no doubt that recycling reduces both the indus-
trial and municipal solid waste streams. However, many
Superfund sites were formerly recycling facilities. Of these,
some were “sham” recyclers and some were legitimate. The
knowledge of future effects of the wastes handled was not
adequate when these facilities were put into operation. Some
operators did not care.
The reader is directed to Recycling, Fuel and Resource
Recovery; Economic and Environmental Factors for specific
information on various industries.
The future of recycling is bright. Public acceptance of
the need for recycling is probably the most important single
development of the past two decades. This acceptance has
given rise to legislative recognition of the importance of the
subject.REFERENCES- Coakley, B.C., Recycling waste materials. The Encyclopedia of Envi-
ronmental Science and Engineering, Vol. 3, Second Edition. Gordon
and Breach Science Publishers, New York, 1983. - Decision-makers guide to solid waste management. US EPA, EPA/530-
SW-89-072 Washington, D.C. 1989. - Documented data from deposit States. Environmental Action. 1986.
- Lees, B., Can we afford to waste municipal waste? National Society for
Clean Waste. Brighton. 1990. - Metals recyclers warily eye sources. Chemical Engineering. pp. 29–35.
Dec. 1990. - Paper recyclings new look. Chemical Engineering. pp. 45–48F. March
1991. - Plastics recycling gains momentum. Chemical Engineering. pp. 37–43.
Now. 1990. - Recycling, Fuel and Resource Recovery; Economic and Environmental
Factors. Encyclopedia Reprint Series. Wiley Interscience. New York,
1984. - Smith, S.J. and L.C. Shera, Material selection; Avoiding the pitfalls.
- Solid Wastes and Power. pp. 36–42. Feb. 1991.
- U.S. industrial outlook. Department of Commerce. Washington D.C.
1990. Report. Task force on solid waste management. National Gover-
nors, Association. 1990.
MARK A. TOMPECK
Hatch Mott MacDonaldTABLE 1
1-PET Polyethylene Terephthalate.
Beverage bottles, frozen food boil-in-the-bag pouches,
microwave food trays. About 7% of the plastic waste
stream.
2-HDPE High Density Polyethylene.
Milk jugs, trash bags, detergent bottles, bleach bottles,
aspirin bottles. About 31% of the waste stream.
3-V Vinyl.
Cooking oil bottles, meat packaging. About 5% of the
stream.
4-LDPE Low Density Polyethylene.
Grocery store produce bags, bread bags, food wraps,
squeeze bottles. About 33% of the total stream.
5-PP Polypropylene.
Yoghurt containers, shampoo bottles, straws, syrup
bottles, margarine tubs. About 9% of the total stream.
6-PS Polystyrene (StyrofoamTM).
Hot beverage cups, fast food clamshell containers, egg
cartons, meat trays. About 11% of the total stream.
7-Other All other plastic resins or mixes of 1–6 in the same
product. About 4% of the stream.Source: Council for Solid Waste Solutions.C018_003_r03.indd 1060C018_003_r03.indd 1060 11/18/2005 11:05:16 AM11/18/2005 11:05:16 AM