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

due to the non-availability of accurate data for the distribution of output flows
between these processes.
As already stated in the methodology, the material flow analysis requires a welldefined
boundary for the system to be analysed. The studied system is completely
located in Colombia, meaning that every process considered in this analysis is taking
place there. The boundary of the system can be seen in Figure 14.
Figure 14: Schematic representation of the MFA system and boundary as defined in this study.
3.4.2 Model scenarios
Three different scenarios have been studied in order to assess possible ranges for
the results given that most of the input data is not very precisely known. Only some
of the flows – most of the flows entering or coming from the “social refurbishment”
and “formal treatment” processes – were considered constant between the three
scenarios, since they were based on information from the registers these institutions
have to keep and they were willing to share. All the missing flows can be determined
by setting some parameters that were adjusted according to the three MFA scenarios
(the respective values can be found in Table 13) and are described hereafter.
The total generated computer waste varies according to the lower, middle, and
higher scenarios of waste generation presented in chapter 3.1.
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