Releases of PCDD/Fs, PCBs, PAHs and HCB Through Bottom Ashes from Brick Kilns Operating with Different Kind of Fuels - Results from a Pilot Study in Mexico - A Contribution to the Update and Review of the Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases

摘要

The Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases is aimed at supporting the parties to the Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) in setting up their national implementation plan, which includes the characterization of unintentional releases of POPs (in this case PCDD/Fs, PCBs and HCB) from all relevant sectors. To this end the toolkit combines sector specific activity data with related emission factors for releases to air, land, water, residues and products. In 2007 the Expert Group for updating and improving the Toolkit, chaired by the Secretariat of the SC (SSC) and UNEP, identified priority areas of reasearch. The group highlighted the need for screening POPs sources that so far are poorly characterized in the Toolkit. Among these, brick kilns in developing countries were given highest priority since so far, no data were available. The Expert Group recommended as a first step to measure soil or vegetation samples close to (small) brick kilns in developing countries to obtain preliminary orientation as to the impact from this source. In the fore field of the experimental planning the question in how far different kinds of fuels, in particular waste derived fuels, may impact the formation of POPs was approached through the analyses of bottom ashes from kilns co-incinerating waste in comparison with brick kilns operated with virgin wood.The results from bottom ash reveal a distinct impact on the presence of POPs in the brick making process when waste is co-incinerated, thus suggesting to include the brick kilns operated with waste fuels as a different category into the toolkit and to include the issue of co-incineration of waste into the experimental set up.The emission factors via the bottom ashes itself range