Polychlorinated Dibenzo-p-dioxin and Dibenzofuran (PCDD/F) Emission Behavior during Incineration of Laboratory Wastes. Part 2: PCDD/F Profiles and Characteristics of Output Materials

Abstract

This study investigates the polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) profiles of output materials and the influence of Cl content of input materials during the incineration of laboratory waste. The specimens, namely bottom ash (BTA), first quenching tower ash (FQA), secondary quenching tower ash (SQA), baghouse ash (BHA), and stack flue gas (SFG), were sampled and analyzed using high-resolution gas chromatography/high-resolution mass spectrometry, fieldemission scanning electron microscopy (FE-SEM), ion chromatography, and X-ray diffraction (XRD). The Cl content was highest in FQA, followed by that in SQA, BHA, and BTA, and most of the Cl existed in soluble form, especially for FQA and SQA. The Cl mass was mainly distributed in FQA and BTA during incineration. The PCDD/F content of ash in each category was highly related to the Cl level in the input materials. The PCDD/Fs of all ashes and the particulate phase of SFG were mainly 7-Cl or 8-Cl PCDD/Fs, but those of the gas phase in SFG were mainly 4-6 Cl PCDD/Fs. In addition, an increase of Cl in the input materials increased the fractions of 7-Cl and 8-Cl PCDD/Fs. The XRD analysis results indicate that the main crystalline phase in fly ashes was NaCl. FE-SEM images show a porous granular morphology, which is consistent with the XRD analysis results.

Effects of Surfactants on the Removal of Carbonaceous Matter and Dioxins from Weathered Incineration Fly Ash

“…Since organic compounds such as polychlorinated biphenyls (PCBs), CBs and dioxins are hydrophobic (Wang et al, 2012;Liao et al, 2014;Chen et al, 2014), flotation technology has been also used to remove these organic compounds from municipal solid waste incinerator (MSWI) fly ash (Cheruiyot et al, 2015;Lee et al, 2016;Cheruiyot et al, 2016). Furthermore, organic pollutant removal and UC removal have good linear relationship during flotation of MSWI fly ash (Huang et al, 2007).…”

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans at Coastal and High Mountain Areas in Taiwan

“…Combustion processes (Correa et al, 2006;Shih et al, 2006;Chiu et al, 2011) involving chlorine containing organic matter ) such as municipal solid waste incineration (Lee et al, 2003), laboratory waste incinerators (Liao et al, 2014;Wu et al, 2014), hazardous waste incinerators , iron ore sintering plants (Fang et al, 2011), steel and cement kilns (Van Thuong et al, 2014), landfill fires (Moussiopoulos et al, 2006), vehicle tailpipe exhausts (Chuang et al, 2010), boilers , fast food restaurants , coal fire-power plants (Lin et al, 2010b), bio-mass open burning (Shih et al, 2008;Chang et al, 2013;Chang et al, 2014) and dust storms (Chi et al, 2014) have been pointed out to be among the leading primary sources of PCDD/Fs and other dioxin like compounds. The emission of PCDD/Fs from the mentioned processes can be attributed to either their presence the feedstock, or be formed from chlorine containing precursors compounds as well as be formed through the de novo mechanism at certain temperature window Fujimori et al, 2014).…”

Evaluation of Thermal Treatments for Elutriated Mixed Incinerator Ashes. Part 1: Co-Incineration with Laboratory Waste

“…Polychlorinated dibenzop-dioxins and polychlorinated dibenzofurans (PCDD/Fs), which are unintentional by-products in the incineration process, are generated through a series of complex reactions that involve Cl, especially in the incinerator start-up period . Therefore, the PCDD/F content in the ashes generated in an LW incinerator are five to ten times higher than those in municipal solid waste (MSW) incinerators (Wang et al, 2010;Liao et al, 2014). Similar levels have been found in hazardous waste incinerators due to the complicated composition of the input materials (Coutinho et al, 2006;Wang et al, 2014).…”

“…The results show that fly ashes cannot be buried in landfills as general industrial waste even after solidification with cementation. In addition, the PCDD/F levels in fly ashes that included the ELA in the incinerator were higher than those in the fly ashes without it, indicating that reincineration of ELW will increase the PCDD/F levels in fly ashes (Liao et al, 2014). Table 5 shows the PCDD/F distribution in the output materials, namely BTA, PQA, SQA, FFA, WSA, and flue gas.…”

“…The Cl content in the feed materials (11.0%) was nearly two orders of magnitude higher than that for MSW. Previous studies have reported that high Cl levels in the input materials enhance PCDD/F formation during the incineration process (Aurell et al, 2009;Liao et al, 2014). The Cl in the input materials has been shown to transform into chlorinated organic compounds or metal chlorides and to serve as a catalyst for PCDD/F formation (Hatanaka et al, 2005;Chin et al, 2012).…”