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.
Aries
Eric
E
Corus Research, Development and Technology, Swinden Technology Centre, Moorgate, Rotherham S60 3AR, South Yorkshire, UK. eric.aries@corusgroup.com
Anderson
David R
DR
Fisher
Raymond
R
Fray
Trevor A T
TA
Hemfrey
Derek
D
D000393:Air Pollutants / Q000032:analysis*; D001572:Benzofurans / Q000032:analysis*; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D007501:Iron; D008669:Metallurgy; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D006113:United Kingdom
D000393:Air Pollutants; D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls; D007501:Iron