Page 198 - Materials Chemistry, Second Edition

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Municipal Solid Waste

7 Processing; Materials Recovery

Facilities

Sooty, swarthy smiths, smattered with smoke,
Drive me to death with the din of their dents.
Such noise at night no man heard, never;
With knavish cries and clattering of knocks!
… They spit and sprawl and spill many spells;
They gnaw and gnash, they groan together
And hold their heat with their hard hammers
Heavy hammers they have that are hard-handled,
Stark strokes they strike on a steely stump

Anonymous, ca. 1400
The Blacksmiths

7.1 INTRODUCTION

The ideal resource recovery scenario in any community would include thorough segregation of indi-
vidual waste components by each homeowner, commercial establishment, industry or municipal
institution (i.e., at the source). Subsequently, the individual products (e.g., aluminum cans, paper,
glass, and plastics) are collected on a regular basis, stored in separate bins within the collection
vehicle, and transported to a facility for further processing (densifying, shredding). These slightly
processed, clean materials would then be sold to and removed by buyers for eventual reprocessing.
The above scenario would result in a clean and highly marketable resource, thus decreasing the cap-
ital expenses for purchase of large separation equipment, energy costs, and labor. Since the above
approach for materials separation from MSW is often not feasible due to lack of information, lack
of participation, and insufficient support from local and state governments, another approach is
often be needed.

7.2 THE MATERIALS RECOVERY FACILITY

The materials recovery facility (MRF) is a relatively recent approach to MSW management, but its
utility has become obvious and its popularity is increasing. In 1898 the first MRF was built in New
York City. The facility processed the waste of over 116,000 residents and recovered up to 37% (by
wt) of the wastes. More recently, the first modern MRF was established in the 1980s in Groton,
Connecticut. Despite facing a volatile market for materials, the number of MRFs has grown
markedly over the past decade. In 1991, a total of 40 projects were planned or operated. Two years
later, this number had quadrupled to 166. In 1995, another doubling occurred to 307 projects. By
1997 the trend had slowed; about 40 new or expanded projects came on line between 1995 and 1997
(Berenyi, 2001). Since 1995, when the implementation of curbside recycling collection programs
had spread across the country, MRFs began to be found in nearly equal proportion by region.

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