Classy Solutions to Classical Problems
Madagascar: From lorry to ship and
back to Europe - return to sender is the most common method of disposal. (1)
Madagascar: From lorry to ship and
back to Europe - return to sender is the most common method of disposal. (2)
Madagascar: From lorry to ship and
back to Europe - return to sender is the most common method of disposal. (3)
Few waste disposal techniques actually satisfy the goals of -
and stringent legal requirements for - the environmentally sound disposal of
hazardous waste. Suitable waste disposal facilities are few and far between,
particularly in developing countries, many of which have none at all. Among
experts, the incineration of pesticides at temperatures above 1,000°C in
special high-temperature incinerators is viewed as the presently most economical
and environmentally sound form of waste management.
While diverse research institutions in industrialized countries
are investigating new methods of disposal, each of them tends to be focused on
certain specific problems, usually on a small scale. Such methods are only of
conditional value for developing countries, where large quantities of obsolete
pesticides and baseline pollution are in need of disposal. Often, the waste in
question does not consist of pure substances but of mixtures made up of several
substances that are no longer individually identifiable. In almost all cases,
there are also contaminated containers, canisters, pallets and soil to be dealt
with.
For these reasons, no single technique can be recommended. Each
new case requires new reflections and new decisions.
In earlier times, for lack of suitable facilities, proper
disposal in developing countries was a rare occurrence. In fact, that is
basically the case even now. Frequently, the only solution is to take the
pesticides to an OECD country for destruction in a dedicated high-temperature
incinerator. Such consignments could well carry the stamp “Return to
Sender”, because it was the industrialized world that sent the pesticides
to the developing countries in the first place. This is seen as the
“classical” or traditional disposal route.
|
Bad Disposal Options
The following options are unsuitable for the disposal of
obsolete pesticides:
- landfilling
- land burial
- deep-well
injection
- solar evaporation
- land application
-
controlled burning |
On the other hand, it also amounts to a risky, expensive
business. It involves huge inputs, beginning with the tendering procedure, for
there are very few disposal enterprises that are really focused on the special
situation of developing countries.
Time and again, the administrative scope is direly
underestimated. The Basel Convention and the EU directives pertaining to the
transboundary movement of waste have, in principle, created effective
instruments with which to prevent “waste tourism”. This, in turn,
presents other problems: The original intent was to put a stop to the cheap
disposal of hazardous waste from industrialized countries in the Third World.
That has met with only partial success. Indeed, these same rules often
effectively hamper the reverse route, too: No matter how they originally
acquired the hazardous waste, developing countries and those charged with their
waste disposal encounter substantial bureaucratic obstacles in trying to get
toxic waste out of the country.
Figure
|
Disposal parameters
The cost of toxic waste disposal, and the procedures to be
employed, depend on a number of parameters.
Liquid waste is the easiest to handle. It can be delivered to
the disposal facility in drums or large tanks. The analysis and interim storage
of waste in large tanks are less complicated and, hence, less expensive. In such
tanks, the waste can be mixed with other liquids and adjusted to a certain
energy level, as required for continuous operation of the combustion plant
(incinerator). Moreover, the incineration of liquid waste produces little, if
any, residue.
Solid and pasty products, though, require pre-incineration
conditioning. Many such products consist of inhomogeneous substances that are
difficult to analyze. Solid waste requires homogenization or shredding, plus
transfer to a suitable container, prior to its introduction into the combustion
chamber. Solid and pasty forms of waste produce more ashes. That, in turn,
incurs landfilling fees and, hence, makes the overall disposal operation more
expensive.
The combustion gases produced by waste containing substantial
amounts of halogens, phosphorus and sulfur require scrubbing to avoid the
emission of acetic gases and to preclude formation of dioxins and dioxylfuranes.
Such measures are also very expensive and must be accounted for in the final
price.
One crucial factor is how the waste is packaged. If it comes in
large tanks, a brief analysis will suffice to confirm the tank’s contents.
If, however, it arrives in small, unlabeled drums, extensive analysis will be
required to avoid unnecessary risks during subsequent treatment of the waste.
That, of course, is a considerable expense factor. Drums, too, have to be
individually examined and treated as solid waste when they are empty, because
the residual deposits are very difficult to remove. |
Mauritania: The crushed drums were
also sent back for disposal.
Nevertheless, as long as the country in question has no
reasonable domestic alternatives, this remains the only possibility. Moreover,
the industrialized countries carry a special measure of responsibility in
connection with pesticides, for it was they who in one way or another were
involved in the supply of most pesticides in the first place. The special
incinerators are located there, as are the producers of the subject substances,
i.e., the keepers of the product-specific know-how.
For that reason alone, the producers should be involved in
disposal planning from the very start. Indeed, the producers’ commitment
has waxed significantly in recent years (cf. section 6). If industry were made
to systematically share in the expenses of disposal, this would mean a tangible
disburdenment of public-sector development assistance. After all, it costs
between US $ 2,500 and US $ 4,500 per ton to return pesticide waste to an
industrialized country. This covers the cost of everything from stocktaking to
the actual incineration.
It would, of course, be disastrous to adopt unsuitable methods
in order to save money. Hasty activism can cause serious damage that would cost
even more to fix afterwards. Certainly, the problem cannot be solved by simply
burying or burning the pesticides.
Nor is there any reason to act prematurely if the potential
risks are systematically assessed. Immediate hazards to human health or the
environment can be warded off by initial remedial measures, perhaps even the
mere refilling of chemicals into new containers. This will always buy enough
time for subsequent well-planned forms of disposal.
This could include returning the waste to its country of origin,
if that is the only possibility.
Pakistan has accumulated one of the
world’s largest stockpiles of obsolete pesticides.
Figure
Step by step: From identification to
evaluation.
