Unintentional production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes

Abstract

Iron ore sintering (SNT) processes are major sources of unintentionally produced chlorinated persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). However, few studies of emissions of brominated POPs, such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), during SNT have been performed. Stack gas and fly ash samples from six typical SNT plants in China were collected and analyzed to determine the concentrations and profiles of PCDD/Fs, PCBs, PCNs, PBDD/Fs, and PBDEs, as well as any correlations among these compounds. The PCDD/F, PCB, PCN, PBDD/F, and PBDE emission factors were 2.47, 0.61, 552, 0.32, and 107μgt, respectively (109, 4.07, 10.4, 4.41 and 0.02ng toxic equivalents t, respectively). PCBs were the most abundant compounds by mass, while PCNs were the next most abundant, contributing 51% and 42% to the total POP concentration, respectively. However, PCDD/Fs were the dominant contributors to the chlorinated and brominated POP toxic equivalent concentrations, contributing 89% to the total toxic equivalent concentration. The PCDD/F and other chlorinated and brominated POP concentrations were positively correlated, indicating that chlorinated and brominated POP emissions could be synergistically decreased using the best available technologies/best environmental practices already developed for PCDD/Fs.

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

“…In the study of Drage et al (2014), the authors did not report their PBDE emission factors of sintering plants, but it seems that PBDE emission factors of sintering plants in the United Kingdom were much higher compared to those in other studies (Wang et al, 2010b, c;Li et al, 2017), because their PBDE concentrations in the stack flue gases (295 ng Nm -3 , BDE-209 not measured) were one order higher than others (22.2 ng Nm -3 , BDE-209 included) in Wang et al (2010b).…”

“…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).…”

“…On the other hand, Wang et al (2010b) applied the geometric mean (GM) of PBDEs:PCDD/Fs I-TEQ ratios to estimate PBDE emissions from combustion sources based on Taiwanese PCDD/F inventory, and found the emission (Li et al, 2017) 109 ng WHO-TEQ tonne Average from coal power plants (Wang et al, 2010b) Power plants (fuel) 0.348 mg tonne-fuel -1…”

Application of national pollutant inventories for monitoring trends on dioxin emissions from stationary industrial sources in Australia, Canada and European Union

“…Iron and steel industry was the prominent emitter of dioxins in Canada, followed by electricity generation. According to the Chinese National Implementation Plan for the Stockholm Convention (2007), iron ore sintering is the highest (30%) emitter of dioxins as compared to other chlorinated POPs [49].…”

Formation mechanism of unintentionally produced persistent organic pollutants in industrial thermal processes

“…在工业热过程中, 多种UP-POPs之间具有一定的 相关性 [1,58] , 这就预示着影响其生成的关键因素存在 着一些共性特征. 因此, 本部分重点讨论工业热过程 中影响UP-POPs生成的关键因素(表1).…”