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

4 FINAL REMARKS
4.1 Computer waste generation
The market supply method used for the calculation of the computer waste generation
was already employed in another study (Streicher-Porte et al., 2005) and used as
validation for a more complex e-waste generation model in Chile (Steubing, 2007).
The generation data was needed as input for the calculations done in the MFA. An
adaptation of the market supply method to take into account informal activities (e.g.
illegal imports) and the recirculation of components, as it occurs in the refurbishment
process, was made. However, this included the addition of two coefficients and no
objective data was available to correctly quantify them. The different computer waste
generation scenarios considered (lower, middle and higher) were, thus, based on
relatively large variations of these parameters in order to consider a wide range of
possible values. Another hypothesis made for the waste generation was the constant
lifespan over the time. Normally, the lifespan of electronic equipments is rather
decreasing, as the ever-accelerated development of newer technologies reduces the
time before equipments are considered obsolete.
The only available study that calculates PC waste in Colombia before is Ott’s study in
2008. Ott’s calculations were based on five scenarios using import and sales data as
input and assuming different lifespan or obsolescence rates, the results range until
2013. The waste generation results computed are in accordance with those by Ott,
except for the inferior limit, which is lower in this study. This is due to mainly two
reasons: the consideration of differentiated weights between CRT- and LCD-monitors
that were not considered in Ott’s study and the inclusion of peripherals in addition to
computers for some of Ott’s models. The novelty of the present model is the
differentiation into the type of devices and the resulted computer waste predictions
until 2020, based on market predictions assumed from literature. The observed
changes in the waste flow compositions constitute important information for the
adaptation of the recycling facilities to the differences in treatment between CRT- and
LCD-monitors or laptops and desktop computers.
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