PCDD/F AND PCB EMISSION FROM STEEL PRODUCING, PROCESSING AND RECLAMATION PLANTS WITH VARYING INPUT

Flue dust samples from the steel reclamation plants contained PCDD/F ranging from 3.5 to 6.7 ng TE (BGA)/g [3.5 - 6.0ng I-TEQ/g]. PCDD/F in flue gas ranged from 0.9 to 2.5 ng TE (BGA)/Nm(3) [0.9 - 2.7 ng I-TEQ/Nm(3)] resp. 0.1 to 3.3 ng TE CBGA)/Nm(3) [0.1 -2.3 ng I-TEQ/Nm(3)]. PCDD/F in clean gas ranged from 0.03 to 0.1 ng TE (BGA)/Nm(3) [0.02 - 0.1 ng I-TEQ/Nm(3)] resp. 0.4 ng TE (BGA)/Nm(3) [0.2 ng I-TEQ/Nm(3)]. Highest contamination (in TE) always occurred after addition of scrap with a high content of nonmetals resp. of MWI scrap. Although these PCDD/F concentrations in clean gas lie 5-to 400-fold under present emissions of MWIs (1 to 10 ng I-TEQ/Nm(3)), these results are no argument for neglecting this source as potential environmental input of PCDD/F. Here, a look at the freights is necessary.