Distribution of Polybrominated Diphenyl Ethers (PBDEs) in a Fly Ash Treatment Plant

Abstract

PBDES are used as the flame retardants and have adverse effects on human health. Electric arc furnaces (EAF) are one of major emission source of PBDEs. The PBDE contents in the fly ashes of an EAF (29.3 ng/g) examined in this study were one to three orders higher than those in environmental soils. EAF fly ash treatment plants are established to resolve the disposal of this material, and also to recover the remaining iron or zinc from it. However, very little is known about the fate of PBDEs in EAF fly ash treatment plants. The EAF fly ash treatment plant investigated in this work can be divided into three sub-systems, including a pelletizer, reducing furnace and submerged arc furnace (SAF). The fly ash generated from the pelletizer process exhibited the highest PBDE content (7.69 ng/g), and contributed about 91% of the total PBDE inputs (4.40 g/day). The total PBDE concentrations in the stack flue gases of the pelletizer, reducing furnace and SAF were 24.5, 2.88 and 4.71 ng/Nm 3 , respectively. The high PBDE concentrations of the pelletizer resulted from not only the thermal desorption of lighter brominated congeners, but also fugitive particles of EAF fly ashes. Together, the three stacks accounted for 40.8% of the total PBDE outputs, revealing that the air pollution control devices deployed in the current study were not very effective with regard to removing PBDEs from the flue gas. The PBDE output/input ratio of the EAF fly ash treatment plant was 0.0378, and thus most PBDEs introduced into the system were decomposed. The EAF fly ash treatment plant examined in this work is thus a reliable facility with regard to the disposal of this material.

Overview and Perspectives on Emissions of Polybrominated Diphenyl Ethers on a Global Basis: Evaporative and Fugitive Releases from Commercial PBDE Mixtures and Emissions from Combustion Sources

“…When high PBDEs are inputted into combustion system, the destruction of PBDEs is dominant (Wang et al, 2010a;Liao et al, 2012;Chang et al, 2013a;Drage et al, 2014), whereas when the input of PBDEs is fewer, the formation of PBDEs is more apparent (Wang et al, 2010b;Chang et al, 2014a, b, c;Chen et al, 2017). Similar phenomena are observed with PAHs (Cheruiyot et al, 2015).…”

“…It should be noted that PBDE emissions from stationary and mobile combustion sources to the atmosphere were not included in the PBDE inventory of Schenker et al (2008). (Odabasi et al, 2009;Wang et al, 2010a, b, c;WyrzykowskaCeradini et al, 2011;Liao et al, 2012;Chang et al, 2013bChang et al, , 2014bDrage et al, 2014;Li et al, 2015;Tsai et al, 2016;Chen et al, 2017;Li et al, 2017). Combustion sources possess high PBDE concentrations in the flue gases/exhaust (one to three orders higher than those in indoor and workplace air), huge flue gas flow rates and numerous amounts (e.g., vehicles), revealing their importance on contributing significant PBDEs to the atmosphere (Wang et al, 2010b).…”

“…Drage et al (2014) carried out PBDE mass balances study at a full scale sinter plant, and found PBDEs in the raw materials were mostly destroyed during the sintering process (79-96%). Likewise, most of the PBDEs in the feedstock of fly ash were depleted in a fly ash thermal treatment plants (Liao et al, 2012). Although high PBDE destruction efficiencies in the combustion system can be obtained, the residues of PBDEs could still cause some environmental issues.…”

Atmospheric Occurrence and Gas-Particle Partitioning of PBDEs in an Industrialised and Urban Area of Florence, Italy

“…The afore-mentioned products constitute the main sources of PBDEs in the atmosphere, together with the other "secondary" sources, as for example are the emissions from vehicular exhausts (e.g., Hsieh et al, 2011), or waste incinarators, or fly ash treatment palnts (e.g., Wang et al, 2010b;Liao et al, 2012). Three major industrial formulations have been commonly used: penta-, octa-and deca-bromodiphenyl ethers mixtures.…”

PBDE Emissions during the Start-up Procedure of an Industrial Waste Incinerator by the Co-Combustion of Waste Cooking Oil and Diesel Fuel

“…The second and third highest congeners were BDE-206 (6.01-6.36%) and BDE-207 (5.93-5.02%), respectively, among all PBDEs. A comparable trend was also found where the most dominant congeners were in the stack flue gases of the reducing furnace and submerged arc furnace (SAF), suggesting the related combustion processes favored the formation of highly brominated congeners (Liao et al, 2012).…”