| 1. |
- Gong, Wenwen, et al.
(författare)
-
Emission factors of unintentional HCB and PeCBz and their correlation with PCDD/PCDF
- 2017
-
Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 230, s. 516-522
-
Tidskriftsartikel (refereegranskat)abstract
- Hexachlorobenzene (HCB) and pentachlorobenzene (PeCBz) have been listed as unintentional POPs in the annex of the Stockholm Convention and thus, attracted attention by government and researchers. Since the intentional production and use has ceased in most countries, the unintentional releases to the environment have increased. This study gathered 206 and 78 emission factors (EFs) of unintentional HCB and PeCBz from scientific publications and governmental reports, respectively. Most of the EFs referred to the release vector "air" (EFAir) and to a less extent to "product" (EFProduct). EFs were proposed for different source categories/classes used in the Toolkit according to the technologies that released the HCB or PeCBz. Overall, lowest and highest EFAir for HCB were found in the metallurgical industry range from 1 μg/t in well controlled plants (coke, iron and steel) up to 40,000 μg/t (secondary zinc). EFs for PeCBz were in similar order of magnitude. Due to lack of data, EFs to water, land or residue cannot be proposed. Using linear regression and statistical analysis such as Pearson correlation, we found strongest correlation of EFAir between HCB and PeCBz (R(2) = 0.79, P < 0.01) and weaker, but still significant, correlations for EFAir between PCDD/PCDFTEQ and HCB (R(2) = 0.56; P < 0.01) or PeCBz (R(2) = 0.31 P < 0.01) for various thermal processes.
|
|
| 2. |
- Gong, Wenwen, et al.
(författare)
-
Reassessment and update of emission factors for unintentional dioxin-like polychlorinated biphenyls
- 2017
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 605, s. 498-506
-
Tidskriftsartikel (refereegranskat)abstract
- One of the major goals of the Stockholm Convention on Persistent Organic Pollutants is to continuously reduce the releases of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-paradioxins and dibenzofurans (PCDD/PCDF) or polychlorinated biphenyls (PCB) from anthropogenic sources. Until now, most efforts have focused on the releases of PCDD/PCDF and to a lesser extent on unintentionally generated PCB, and therefore, release inventories reported as toxic equivalents (TEQ) do not include the twelve dioxin-like PCB (dl-PCB). In order to facilitate the development of national release inventories for the total TEQ - consisting of PCDD, PCDF and PCB - this study collected and summarized published emission factors (EFs) of unintentional dl-PCB or calculated them from measured data for the sources listed in the UNEP Toolkit. In total, 286 EFs for dl-PCB were found (or could be calculated) whereby 233 described release to air, 23 EFs addressed to residue, 25 EFs to product; and only 5 EFs addressed releases to land. Taking into account performance criteria such as the facility type and scale or abatement technologies, the EFs were grouped and assigned to the source categories and/or classes used in the UNEP Toolkit. With these newly added data and EFs of dl-PCB, the already existing EFs in the Toolkit can be improved and amended. In addition, a statistically significant correlation between the EFAir of dl-PCB proposed in this study and EFAir of PCDD/PCDF recommended in the Toolkit was observed.
|
|
