Estimation and characterization of unintentionally produced persistent organic pollutant emission from converter steelmaking processes

Abstract

Unintentionally produced persistent organic pollutants (UP-POPs) including polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) were characterized and quantified in stack gas and fly ash from the second ventilation systems in five typical converters in five different steelmaking plants. POPs in the present study were generally lower than those in other metallurgical processes, such as electric arc furnaces, iron ore sintering, and secondary metallurgical processes. Adding scrap metal might increase UP-POP emissions, indicating that raw material composition was a key influence on emissions. HxCDF, HpCDF, OCDF, HpCDD, and OCDD were the dominant PCDD/Fs in the stack gas and fly ash. TeCB and PeCB were dominant in the stack gas, but HxCB provided more to the total PCB concentrations in the fly ash. The lower chlorinated PCNs were dominant in all of the samples. The 2378-PCDD/F, dl-PCB, and PCN emission factors in stack gases from the steelmaking converter processes (per ton of steel produced) were 1.88-2.89, 0.14-0.76 , and 229-759 μg t −1, respectively.

Comparison of the contributions of polychlorinated dibenzo-p-dioxins and dibenzofurans and other unintentionally produced persistent organic pollutants to the total toxic equivalents in air of steel plant areas

“…The less chlorinated PCN congeners CN-1, CN-2, CN-4, and CN-5/7 were the dominant PCNs in the air samples, contributing 60-96% of the total PCN mass concentrations. The PCDD, PCDF, dl-PCB, and PCN congener profiles in the air were similar to the profiles found in stack gases emitted during the converter steelmaking and iron ore sintering processes (Aries et al, 2006;Li et al, 2014).…”

Variations and factors that influence the formation of polychlorinated naphthalenes in cement kilns co-processing solid waste

“…One reason for this could be the effect of the feeding materials under the flowing gas. Feeding materials make important contributions to PCN concentration and formation during thermal processes [34]. PCNs present in feeding materials could be important sources of PCNs emitted during thermal processes.…”

Removal of polychlorinated biphenyls by desulfurization and emissions of polychlorinated biphenyls from sintering plants

“…The concentrations of PCBs in fly ash from sintering processes have seldom reported, and no other published data on PCB levels from sintering processes are available for comparison. However, the PCBs from some other thermal industries have been reported, including converter steelmaking processes (0.036-0.75 ng g −1 for dl-PCB, 0.03-2.85 pg WHO-TEQ g − 1 ), iron foundries (0.028-9.34 pg WHO-TEQ g −1 ), secondary aluminum production (0.018-10.2 ng TEQ g −1 ), and secondary copper production (0.003-103.1 ng TEQ g −1 ) (Li et al 2014) (Ba et al 2010;Lv et al 2011). The levels of PCBs in fly ash samples from sintering processes were far higher than those of converter steelmaking processes, iron foundries, secondary copper production, and secondary copper production.…”

“…Consequently, unintentional emissions of PCBs during industrial thermal processes have been becoming, and will continue to become, more important sources of PCBs in the environment. These thermal emission sources of PCBs include iron sintering, secondary nonferrousmetal smelting, iron casting, coking, and converter steelmaking; iron-ore sintering is an important industrial source of PCBs (Ba et al 2010;Ba et al 2009;Li et al 2014;Liu et al 2009a;Liu et al 2009b;Luthardt et al 2002;Lv et al 2011;Tian et al 2012). The environmental presence and behaviors of PCBs have been studied for more than 30 years (Li et al 2010).…”