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Toolkit for Identification and Quantification of Releases of Dioxins, Furans and Other Unintentional POPs PART III Annexes |
Annex 26 Complementary information to source category 2k Shredders
Overview of recent revisions
For this source category, PCDD/PCDF emission factors for air were confirmed, while a new emission factor was proposed for residues. New emission factors are also proposed for PCBs.
Table III.26.1 PCB emission factors for source category 2k Shredders
2k Shredders Emission Factors (µg TEQ/t recovered steel) Classification Air Water Land Product Residue 1 Metal shredding plants 0.4 15 Emission factors for air emissions are provided with a high level of confidence, as these are derived from a broad geographical coverage and are based on a low data range and not on expert judgment. Emission factors for residues releases are provided with a low level of confidence, as these are based on extrapolations and expert judgment.
Derivation of emission factors
Release to Air
Emissions arise due to the presence of PCB and PCDD/PCDF contained in the feed to the shredder plants such as motor vehicles, household electrical equipment, or other electrical appliances, and are released to the air by the mechanical destruction. An emission factor of 0.2 μg TEQ/t (concentration of 0.04-0.4 ng TEQ/m³) is developed based on data provided by SCEP (1994). This emission factor is confirmed by two other European publications (Schleicher et al. 2009, François et al. 2005). Mean concentrations of 0.14 ng TEQ/Nm³ and 0.023 ng TEQ/Nm³ (10 samples) were measured respectively. Assuming a production of 80 t/h and a gas flow of 65,000 Nm³/h, such concentrations would correspond to emission factors ranging from 0.019 to 0.30 µg TEQ/t of recovered steel.
These two publications also give PCB measurement data. The Belgian one (10 samples from 3 plants) shows concentrations from 0.025 to 0.74 ng TEQ/Nm³ which would correspond to a mean emission factor of 0.32 µg TEQ/t. The Swedish one (10 samples) show concentrations ranging from 0.29 to 0.94 ng TEQ/Nm³, corresponding to a mean emission factor of 0.45 µg TEQ/t of recovered steel. Therefore, a PCB emission factor of 0.4 µg TEQ/t is proposed for the purpose of the Toolkit.
The fact that PCB emission factors are higher than PCDD/PCDF emission factors should be highlighted.
Release to Water
A release to water could occur where effluents are discharged. No data were available to estimate emission factors. Any liquid discharge should be reported and any treatment applied.
Release to Land
No release to land is expected.
Release in Products
It is likely that the products will have some level of contamination on them although it is not possible to estimate this.
Release in Residues
Residues may be materials from dust removal devices or unsellable products from the shredding operation (non-metallic materials). The Belgian study mentioned above also reported data on PCDD/PCDF releases through residues. A value of 0.023 ng TEQ / g of residue is reported. Assuming a release of 200 kg of residues / t of product, such a concentration would correspond to a PCDD/PCDF emission factor of 5 µg TEQ/t of recovered steel. A new emission factor is suggested for PCB from Danish data (Schleicher et al. 2009).
