Annex 27 Complementary information to source category 2l Thermal Wire Reclamation and E-waste Recycling
Overview of recent revisions
Category 2l was revised to specifically include e-waste recycling. A new class was added to cover open burning of circuit boards (new class 2). Some new emission factors for PCBs are also proposed with a medium level of confidence.
Table III.27.1 PCB emission factors for source category 2l Thermal Wire Reclamation and E-waste Recycling
2l Thermal Wire Reclamation and E-waste Recycling Emission Factors (µg TEQ/t material) Classification Air Water Land Product Residue 1 Open burning of cable 400 2 Open burning of circuit boards 3 3 Basic furnace with afterburner and wet scrubber 4 Burning electric motors and brake shoes, etc. – afterburner fitted
Derivation of emission factors
Release to Air
To our knowledge, there are no measured data for emissions from open cable burning and only very few from legal cable burners. Highest concentrations reported for thermal wire reclamation were 254 ng TEQ/m³ (Dutch data) and emission factors up to 500 μg TEQ/t were used in the Dutch and Austrian inventories (LUA 2000); lowest were 3.3 μg TEQ/t. The Swiss inventory applied an emission factor of 2,340 μg TEQ/t (LUA 2000). A literature review and additional experiments carried out in the USA gave very different emission factors for cables on the one hand and circuit boards on the other hand: 28-155 µg TEQ/t for the former and 5,400-18,100 for the latter (Gullett et al. 2007). Experiments achieved in Japan on cable burning showed similar emission factors (Shibata et al. 2003). Therefore, a new class 2 assigned to open burning of circuit boards is proposed. New emission factors for class 1 (open burning of cables) and class 2 (open burning of circuit boards) are proposed to be 12,000 µg TEQ/t and 100 µg TEQ/t respectively.
Class 2 emission factors should be used for cable burning in furnaces fitted with afterburners and wet scrubbers. The concentration of 40 μg TEQ/t for emissions to air was given by Bremmer et al. (1994).
For furnaces burning electric motors, brake shoes and the like and fitted with an afterburner an emission factor of 3.3 μg TEQ/t is used (Bremmer et al. 1994). Any similar recovery operations should be looked at and a note made of the controls applied and any gas cleaning in use.
Dioxin-related compounds in house dust from Vietnamese e-waste recycling sites were characterized and it was shown that PCBs accounted for 3% of the PCDD/PCDF TEQ (Tue et al. 2010). Based on that results and on the proposed emission factors for PCDD/PCDF, the following emission factors for PCBs are proposed for classes 1 and 2: 400 and 3 µg TEQ/t respectively.
Release to Water
Where a furnace is used and a wet scrubber is present a release to water is expected. The presence of wet scrubber systems at such plants should be noted, the fate of effluent and any treatment applied to the effluent noted. No data has been found to derive emission factors.
Release to Land
Releases to land are expected to occur where open processing takes place, the residues in this case will be on the ground. At illegal burning sites, soil concentrations up to 98,000 ng TEQ/kg have been measured. In other cases where residues are removed these will be considered in the Section on residues. In the case of open cable burning contamination of the land can be significant and sites should be identified as potential hot spots.
Release in Products
No release into the copper product is expected.
Release in Residues
Residues from the process are expected to contain PCDD/PCDF and levels may be high. No data were available to estimate releases.