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

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2 METHODS 2.1 Computer waste generation The existing data about computer waste (PC waste) generation in Colombia – needed as starting point for modelling the further processes after use by consumers – is neither abundant nor precise. We know from a previous study that for the year 2009, PC waste generation in Colombia ranged from 6,600 to 12,200 tons (Ott, 2008). These values correspond to the grand total for computers and peripherals without device distinction. 2.1.1 The Market supply method In the present study, a simple method for estimating the PC waste generation is employed, differentiating four categories of computer equipment: Central Processing Units (CPU), laptops, Cathode Ray Tube monitors (CRT-monitors) and Liquid Crystal Displays (LCD-monitors). Calculations are based on the “Market Supply Method” that approximates the number of WEEE of each category produced in the year t , using historical sales figures and the average lifespan ( ls) of the considered device (Rochat et al., 2009). € WEEE generation(t) = Sales(t € − ls) (1) The WEEE potential by weight is then calculated by multiplying the number of WEEE produced for € each device by its average weight. The average weights used for the calculations are those reported in Table 7 as total weights. 2.1.2 The Market Supply Method adapted to informal economies Three scenarios of PC waste generation were taken into consideration. Equation 1 is used to calculate the lower scenario. The middle and higher scenarios are calculated by including in the main Market Supply Method equation an “Informal Sector Coefficient” (ISC) and a “Re-circulated Waste Coefficient” (RWC) (Equation 2). 8
The ISC allows the boost of sales figures in an attempt to take into account the informal market in developing countries that involves activities such as illegal import, local assembly of non-branded products, and electronic equipments bought abroad by travellers (Equation 3). For a completely formal market, the ISC is equal to 1, and for a country where informal sales amount to the number of formal sales, the ISC is equal to 2. The RWC is integrated in an effort to take into account repair and refurbishment activities that feed a low-cost second-hand market by adding the additional waste generated by these activities (Equation 4). If the average lifespan for the second-hand devices is called ls 2 H , then, the RWC would be the percentage of the WEEE generated and re-entering the market in the year accounted for as waste in the year t . € ! WEEE generation DC (t) = ISC " Sales(t # ls) + RWC € " Sales(t # ls # ls 2 H ) € ISC = f (illegal import, non branded, travellers equipments...) ! The parameters used for the model calculations are shown in Table 3. t − ls 2 H that is again Table 3: Parameters for the market supply method adapted to developing countries used in this study for the three different computer waste generation scenarios. Parameter Description PC waste generation scenarios Lower Middle Upper ISC Increase of sales data due to informal sales 1 1.2 1.4 RWC ! RWC = f (Waste from 2nd hand PCs) Second-hand PCs sold at the year t − ls 2 H 0% 15% 30% ls 2 H Second-hand equipment lifespan - 4 4 (2) (3) (4) € 2.1.3 Data collection and assumptions € Historical market data for desktop and laptop PCs was obtained from publications citing IDC Colombia (Ott, 2008 and CCIT, 2009). As information for sales of CRTand LCD-monitors was not available, it was assumed that with every CPU there was one monitoƒr (CRT or LCD) sold, and that the fraction of LCD-/CRT-monitors sold each year was the same as in Chile (Steubing, 2007). According to this, Figure 3 shows the historical and projected sales for the “Middle” scenario. Projections of market evolution were made according to Table 4. 9
Page 3 and 4: Abstract In Colombia, as in other d
Page 5 and 6: Glossary Chatarrerías - A term use
Page 7 and 8: 3.3.2 Informal refurbishment and r
Page 9: List of Tables Table 1: General inf
Page 12 and 13: 1.2 Colombia as case study The Repu
Page 14 and 15: (both laptop and desktop) in Colomb
Page 16 and 17: collection, refurbishment, manual d
Page 20 and 21: Table 4: Parameters used for the co
Page 22 and 23: made. This means that from the tota
Page 24 and 25: 2.3.1 Definitions The following imp
Page 26 and 27: Table 7: Average composition and we
Page 28 and 29: M c ik = ˙ ik ˙ (9) F i The distr
Page 30 and 31: In 2009, waste of more recent techn
Page 32 and 33: 200 and 350 tons. Based on the latt
Page 34 and 35: iggest formal e-waste recycling com
Page 36 and 37: this study, the term “informal co
Page 38 and 39: A pilot project conducted in Bogot
Page 40 and 41: Figure 12: Manual dismantling of co
Page 42 and 43: city. Scrap metal dealers are then
Page 44 and 45: The direct MSW collection rate is t
Page 46 and 47: In the three scenarios, informally
Page 48 and 49: are mixed with common glass, or are
Page 50 and 51: entering the market are almost excl
Page 52 and 53: Non treated (low-grade PWBs) Formal
Page 54 and 55: Refurbish Formal treatment Worst ca
Page 56 and 57: introduction of an Advanced Recycli
Page 58 and 59: Table 15: Theoretical benefit from
Page 60 and 61: 3.5.1.3 Social benefits Allowing th
Page 62 and 63: 3.5.2.2 Environmental benefits Evid
Page 64 and 65: 4 FINAL REMARKS 4.1 Computer waste
Page 66 and 67: possible intervention points. There
Page 68 and 69:
small metal parts that can be sold,
Page 70 and 71:
6 ACKNOWLEDGEMENTS I would like to
Page 72 and 73:
Gmünder S. (2007). Recycling - Fro
Page 74 and 75:
Uribe L.M., Wolfensberger M. y Ott,
Page 76 and 77:
Appendix A.2: List of expert interv
Page 78 and 79:
Appendix B.1: Flow scheme for the
Page 80 and 81:
Appendix C.2: Flow Matrix for the
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