Emissions behavior and distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) from cement kilns in China

Abstract

The production of cement in China is accompanied by various emissions, such as fine particulate matter, heavy metals, nitrogen oxides, sulfur oxides, carbon dioxide…. Moreover, cement kiln presents a potential health risk to its surroundings, linking to emissions of persistent organic pollutants (POPs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), in brief dioxins. Flue gas samples were collected from five typical cement kilns during twelve runs and were used to evaluate the levels and distribution of PCDD/Fs in the emissions from cement kilns. The PCDD/Fs concentrations (136 congeners) and I-TEQ values ranged from 2.3 to >40 ng/m(3) and 9.3~90.8 × 10(-3) ng I-TEQ/m(3), respectively, which were lower than the emission standard in China (0.1 ng I-TEQ/m(3)). In weight units, the dominant congeners were OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF; 2,3,4,7,8-PeCDF is the largest contributor (36-66 %) to the total I-TEQ value of twelve runs. HxCDF and TCDF were the first two most abundant homologue groups (12-85 and 4-52 %), and the homologue concentration decreased with rising chlorine number for PCDDs. In addition, there was no marked difference in homologue profiles when solid wastes (refuse-derived fuel and municipal solid waste) and hazardous wastes (DDT and POPs) were combusted as supplemental fuels. The use of various supplemental fuels had no obvious effect on the fingerprint of PCDD/F homologues. Moreover, there was no significant difference in levels of PCDD/Fs emission due to the diversity of production capacity, which were consistent with reported previously. Air pollution control device had effect on the homologue profiles, and cement system with electrostatic precipitators (ESP) had more fractions of octachloro congeners to the total.

Emissions of PCDD/Fs, PBDD/Fs, dioxin like-PCBs and PAHs from a cement plant using a long-term monitoring system

“…The fact that the use of alternative feedstocks is not related with an increase in dioxin emissions has also been observed by others Conesa et al, 2008;Conesa et al, 2011;Fabrellas et al, 2005;Karstensen, 2008). were the two most abundant homologue groups, and that the homologue concentration decreased with rising chlorine number for dioxin (Chen et al, 2014). Regarding dl-PCBs, Table 2 shows that the predominant congeners were PCB-118, PCB-105, PCB-123 and PCB-77, precisely the same congeners shown in previous studies of clinker kiln emissions (Rivera-Austrui et al, 2014).…”

Field pilot study on emissions, formations and distributions of PCDD/Fs from cement kiln co-processing fly ash from municipal solid waste incinerations

“…Formation and emission of PCDD/Fs from a cement kiln processing a solid fuel recovered from municipal solid waste has been studied [18,19]. Dioxins form in cement kilns, and their release and impact on surrounding environment has been demonstrated [20][21][22][23][24]. However, to date, incineration of MSWI fly ash in a cement kiln has not been performed on an industrial scale or in any pilot studies.…”

Characteristics of particle-bound polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in atmosphere used in carbon black feeding process at a tire manufacturing plant

“…Recent empirical studies have characterized atmospheric particulate matter (PM) and PCDD/Fs from various emission sources (Chen et al 2014;Huang and Liang 2011;Umlauf et al 2010). The PCDD/Fs are lipophilic and stable and have been identified in the fatty tissues of animals and humans (Kimbrough and Jensen 1989).…”