PCDD/F and "Dioxin-like" PCB emissions from iron ore sintering plants in the UK.

Investigations have been carried out at the three Corus UK sinter plants over the period 2002-2004 to characterise the emissions of both 2,3,7,8-PCDD/Fs and WHO-12 PCBs, to estimate annual mass releases of these organic micro-pollutants using the I-TEF and WHO-TEF schemes, and to investigate the formation of PCBs in the iron ore sintering process. Results showed that the sintering of iron ore produces a characteristic WHO-12 PCB and PCDD/F congener pattern that is substantially the same for all UK sinter plants. With regard to WHO-12 PCBs, the most abundant congeners were typically PCBs 118 (6-9 ngNm(-3)), 105 (2-4 ngNm(-3)) and 77 (2-3 ngNm(-3)). All other WHO-12 PCBs were also detected at concentrations around 1 ngNm(-3). All sinter plants investigated exhibited very similar TEQ concentrations. WHO-12 PCB emissions were in the range 0.042-0.111 ngWHO-TEQNm(-3), whereas PCDD/F emissions ranged from 0.39 to 1.62 ngWHO-TEQNm(-3). PCDF congeners were the main contributors to the overall TEQ in sintering emissions (ca. 85%). Amongst WHO-12 PCBs, PCB 126 was the only noteworthy contributor to total TEQ (ca. 5-7%), a similar contribution to that from PCDDs. Based on the measurements that Corus UK has undertaken at these three sinter plants, annual mass releases of WHO-12 PCBs and PCDD/Fs have been calculated. For UK sinter plants, a total mass release of 29.5 g WHO-TEQ per annum [WHO-12 PCBs+PCDD/Fs] has been estimated, representing 9% of the total PCDD/F emissions to the UK atmosphere. Measurements were also carried out at a UK sinter plant to determine the windleg emission profile of WHO-12 PCBs. Results showed that WHO-12 PCBs were formed in the same regions of the sinter strand as 2,3,7,8-PCDD/Fs, indicating that there was a strong correlation between the formation of WHO-12 PCBs and PCDD/Fs in the iron ore sintering process.

[1]  F. N. Fett,et al.  Thermisches Betriebsverhalten einer Bandsinteranlage , 1987 .

[2]  D. Ball,et al.  Agglomeration of iron ores , 1973 .

[3]  Safe,et al.  Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. , 1998, Environmental health perspectives.

[4]  David R Anderson,et al.  Sources of dioxins in the United Kingdom: the steel industry and other sources. , 2002, Chemosphere.

[5]  Helmut Greim,et al.  The international toxicity equivalency factor (I-TEF) method of risk assessment for complex mixtures of dioxins and related compounds , 1990 .

[6]  P. Dyke,et al.  Changes to the TEF schemes can have significant impacts on regulation and management of PCDD/F and PCB. , 2002, Chemosphere.

[7]  H. Vogg,et al.  Thermal behavior of PCDD/PCDF in fly ash from municipal incinerators , 1986 .

[8]  S. Marklund,et al.  Secondary Formation of Chlorinated Dibenzo-p-dioxins, Dibenzofurans, Biphenyls, Benzenes, and Phenols during MSW Combustion , 2000 .

[9]  Ulrich Quass,et al.  The European dioxin air emission inventory project--final results. , 2004, Chemosphere.

[10]  H. Yamazaki,et al.  De novo formation characteristics of dioxins in the dry zone of an iron ore sintering bed. , 2004, Chemosphere.

[11]  K. Ballschmiter,et al.  Reaction pathways for the formation of polychloro-dibenzodioxins (PCDD) and —dibenzofurans (PCDF) in combustion processes: II. Chlorobenzenes and chlorophenols as precursors in the formation of polychloro-dibenzodioxins and —dibenzofurans in flame chemistry , 1988 .

[12]  D. R. Anderson,et al.  Studies into the formation of dioxins in the sintering process used in the iron and steel industry. 1. Characterisation of isomer profiles in particulate and gaseous emissions. , 2003, Chemosphere.

[13]  J. Fuchs,et al.  Total TEQ emissions (PCDD/F and PCB) from industrial sources. , 2002, Chemosphere.

[14]  Jones,et al.  Improvements to the UK PCDD/F and PCB atmospheric emission inventory following an emissions measurement programme , 1999, Chemosphere.

[15]  C. Young,et al.  Pic formation mechanisms in the thermal decomposition of 1 2 dichlorobenzene , 1991 .

[16]  Perng-Jy Tsai,et al.  Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack flue gases of sinter plants. , 2003, Chemosphere.

[17]  David R Anderson,et al.  Development and validation of a method for analysis of "dioxin-like" PCBs in environmental samples from the steel industry. , 2004, Chemosphere.