10 07 29 Master thesis Juliana Leon - e-Waste. This guide

possible intervention points. Therefore, this model could be used in the future as a
tool when developing strategic plans for the implementation of alternative systems.
However, the model relies on certain assumptions; some limiting factors are:
• By definition, the model is a simplification of the reality;
• The consumers’ disposal habits are partly estimated; and
• The model reflects only what is happening in large cities and, although it is
known that majority of computers are in these areas, it might not reflect the
nationwide reality.
Although the model was not implemented precisely aiming at economical analysis or
environmental assessment, such further applications are feasible. The model
proposed can serve as a basis for an Economically Extended MFA by introducing
economical values such as the market price for each flow and the added value for
each process. The model can also lead to further calculations of the environmental
impacts associated with each process by introducing data such as material recovery
(or loss), energy consumption, and emissions generated.
By adapting some entries, such as consumer habits, refurbishment rate and formal
disposal possibility, the model could be applied to other e-waste categories such as
TVs and printers, photocopiers, and video recorders. Nevertheless, other smaller
devices such as mobile phones, digital cameras, or music devices may not behave
similarly, especially considering the storage, which might be longer, and or collection
by MSW trucks.
Although the quantity of informally processed PWBs is always lower than the one
that is formally treated, the “worst scenario” features up to 295 tons of computer
PWBs that might undergo artisanal processes, making this practice perhaps not as
sporadic as initially thought. However, this practice is really clandestine and the field
survey did not allow knowing further details, which makes it really complicated the
discussion of numbers found. The only point of comparison existing is an estimation
of 5 tons per month given by CI Recycables after their own investigations following a
decrease in the amount of PWBs received in some cities (Jaramillo, 2010). This
estimation of 60 tons/year is close to the base scenario, where this represents 76
tons/year.
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