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John
Trotti
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Can you
please tell me what will happen in the future in MSW?
(1) Will the major types of waste produced change? (2)
What future trends in waste technology do you foresee?
(3) Will a new industry of waste management be built?
(4) What role will source reduction, recycling, composting,
waste combustion facilities, and landfills play?
Recently
I received the above questions from a student, and I'd
like to share some thoughts with the promise that we'll
iinvestigate each of these issues in greater depth throughout
the year.
Change
in Waste Feedstocks. Don't expect to see
these change in any substantive or dramatic way. After
all, waste is waste–materials for which there is
no longer sufficient economic value to rescue from disposal.
Technological
Change. There are a number of technologies in
the wings, especially the conversion of waste organics
directly into energy (incineration) or fuels and other
products (e.g., pyrolysis, acid hydrolysis, anaerobic
digestion). While incineration is the easiest, quickest,
most cost-effective solution, it carries a lot of baggage
from the days before emissions controls. Though typically
more expensive and generally somewhat less energy-efficient,
nonburn technologies permit the production of a wide
range of storable fuels and value-added materials that
do not carry with them the stigma of smoke and air pollution
and are thus more apt to gain public acceptance.
Emergence
of New Approaches. American manufacturers have
enjoyed cheap labor, increasingly productive extraction
machinery, generous tax credits, and a reasonably secure
supply chain of raw materials to hold costs in check.
The rise of a global economy, however, will change much
of this, increasing the demand for recycled materials.
Waste management assumptions and practices will have
to accommodate what amounts to a fundamental change
worldwide in the value and distribution of materials.
Role
of Specific Practices. Source reduction
is a social phenomenon that runs counter to the public's
present-day consumption ethic. Its impact is on the
industrial side of the ledger where any reduction in
the use of materials in achieving a particular product
or "good" is to the producer's advantage.
While reuse and recycling are able to
extend the life of some materials, by and large these
are delaying tactics. I believe that the recycling practices
for these materials have matured to the point that the
costs associated with increasing their yields are so
far beyond any benefits to be derived that if we were
to proceed on a purely environmental basis we would
reduce our recycling efforts for all but the metals.
Any gains in recycling will have to come from the development
of markets for materials that are presently thrown away,
and these are for the most part the nonrecyclable organics
that account for 67% of materials going to landfills.
While attractive
in theory, MSW composting is costly and fraught
with problems. Odor alone virtually guarantees successful
opposition to construction of an open-air facility anywhere
near the people and industries that generate the feedstocks.
Siting where no one will complain often means that hauling
costs to and from the facility will eat up whatever
slight value might have been leftover from the operation.
From time to time you hear of high-value compost commanding
a good price. True, but rarely do you find either MSW
or biosolids in these products.
Right now
we are on the brink of major changes not only in how
landfills are constructed but what role they
are to play in the future. We are just beginning to
explore engineered bioreactor landfills, and there are
still many questions to be answered. Were I a betting
man, however, I'd wager that in less than 20 years
we will place nonrecyclable organics in multicelled
vaults where they will undergo accelerated degradation
and stabilization by both aerobic and anaerobic means.
Moreover, once stabilization has been achieved, these
vaults will be mined for their treasure of soil. Though
advances in engineering techniques and materials will
play a large role, the real driver will likely lie in
the area of public policy, where municipal planners
will be able to incorporate the MSW disposal element
into their strategic plans.
Finally (for
the moment), if you look out 50 years into the future,
you might see some very interesting possibilities in
the nature of materials used in the production of many
of the goods now made from virgin materials. Until very
recently, nanotechnology has existed in some very way-out
habitats that have little or nothing to do with the
economic mainstream. But recent advances in developing
molecular building blocks for purpose-built materials
have pushed this past the wishful-thinking stage. While
no one expects overnight results, I would be surprised
if we don't see nanotechnology beginning to make
its presence felt as early as by the end of this decade.
Once a year
I get out my soapbox and rattle off some thoughts in
the hope of stirring up some conversation. If you find
my vision a little garbled, please accept in its stead
my wish for a very exciting and rewarding 2002.
-----
Correction
The article
"Is Piling It Higher and Deeper the Only Answer?"
(September/October 2001) erroneously referred to
NRC as National Recycling Council rather than its correct
name, the National Recycling Coalition. The article
went on to say, "NRC would have our society ban
landfills and recycle everything." The NRC's position
is that "no one has yet to demonstrate that they
can safely manage the organic fraction of the wastestream
in landfills for even a short period of time, much less
the centuries that lined landfills remain biologically
active." Interested readers can review the NRC's
documents on this subject at its Web site, www.nrc-recycle.org.
MSW Management
will pursue this and other subjects related to bioreactor
landfills in subsequent issues.
Send John an Email
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