生活垃圾焚烧残灰中有毒成分的排放特性

Abstract

Abstract:In this study, eight fly ash samples and three bottom ash samples from different areas are collected for analysis of their physicochemical properties and emission content of dioxin precursors and metals. Their surface characteristics, their effects on dioxin precursors, and important aspects of the compositions of residual ash (fly ash and bottom ash) are investigated. Poly-chlorobenzenes (PCBzs) in the fly ash of a fluidized bed incinerator (FBI) are 7.35 to 357.94 µg/kg, and in that of a fire grate incinerator (FGI) are 6.74 to 96.52 µg/kg. The concentrations in bottom ash are the same (i.e., 2.23 to 2.99 µg/kg) regardless of the furnace type. The concentrations of polycyclic aromatic hydrocarbons (PAHs) in FGI fly ash samples (0.293 to 1.783 mg/kg) are less than these in samples from FBIs (1.820 to 38.012 mg/kg). Low boiling point PAHs (mainly 2-and 3-ringed PAHs) and high boiling point PCBzs (mainly H x CB and P e CBz) are the major constituents of residual ash. Different distributions of PCBzs and PAHs are mainly dictated by the incineration characteristics of FBI and FGI. Al and Fe, as non-toxic "light metals" are the major constituents of the residual ash, and Ni and Zn as non-toxic heavy metals play important roles in the total heavy metal. Cu, Pb, and Cr are the three major toxic heavy metals. The correlation of the metals and the dioxin precursors is discussed and distinguished.

Concentrations, profiles, emission inventory, and risk assessment of chlorinated benzenes in bottom ash and fly ash of municipal and medical waste incinerators in northern Vietnam

“…For fly ash, concentrations of CBzs in Vietnamese samples (2.70-405 ng g −1 for Σ7CBzs) were comparable to the range found in several Chinese incinerators (6.74-358 ng g −1 for Σ12CBzs; Li et al 2015) but still lower than those measured in fly ash from two grate-type municipal waste incinerators in Japan (870-1900 ng g −1 for Σ12CBzs; Takaoka et al 2003). Concentrations of HCBz and PeCBz in the Vietnamese fly ash samples fall in the low to moderate range when compared to levels recorded in the Japanese and Chinese samples (Takaoka et al 2003;Yan et al 2011;Li et al 2015;Zhang et al 2018). Nevertheless, numbers of investigated facilities and analyzed samples of these studies (including the present study) were relatively small, and lists of target compounds were different among studies, which may lead to incomprehensive evaluation and inadequate comparison.…”

“…The data in Table S2 do not show clear relationship between the extent of CBzs formation in bottom ash and different types of waste and furnace. Although our results on Vietnamese bottom ash exhibit higher concentrations of CBzs in samples from fluidized bed incinerators than grate ones (Hue et al 2016(Hue et al , 2019a, levels of CBzs were not significantly different in bottom ash of these two incinerator types from China (Li et al 2015). For fly ash, concentrations of CBzs in Vietnamese samples (2.70-405 ng g −1 for Σ7CBzs) were comparable to the range found in several Chinese incinerators (6.74-358 ng g −1 for Σ12CBzs; Li et al 2015) but still lower than those measured in fly ash from two grate-type municipal waste incinerators in Japan (870-1900 ng g −1 for Σ12CBzs; Takaoka et al 2003).…”

“…Although our results on Vietnamese bottom ash exhibit higher concentrations of CBzs in samples from fluidized bed incinerators than grate ones (Hue et al 2016(Hue et al , 2019a, levels of CBzs were not significantly different in bottom ash of these two incinerator types from China (Li et al 2015). For fly ash, concentrations of CBzs in Vietnamese samples (2.70-405 ng g −1 for Σ7CBzs) were comparable to the range found in several Chinese incinerators (6.74-358 ng g −1 for Σ12CBzs; Li et al 2015) but still lower than those measured in fly ash from two grate-type municipal waste incinerators in Japan (870-1900 ng g −1 for Σ12CBzs; Takaoka et al 2003). Concentrations of HCBz and PeCBz in the Vietnamese fly ash samples fall in the low to moderate range when compared to levels recorded in the Japanese and Chinese samples (Takaoka et al 2003;Yan et al 2011;Li et al 2015;Zhang et al 2018).…”

“…Available information on the presence of CBzs in the bottom ash is relatively limited, especially for multiple congeners other than HCBz and PeCBz. Concentrations of CBzs and HCBz in the bottom ash from several Vietnamese municipal, medical, and industrial waste incinerators were generally higher than those measured in some medical and municipal waste incinerators in China (Yan et al 2011;Li et al 2015). The data in Table S2 do not show clear relationship between the extent of CBzs formation in bottom ash and different types of waste and furnace.…”

“…Residual ash (i.e., bottom ash and fly ash) from waste incinerators has been characterized as potential sources of CBzs, and previous studies mainly focused on HCBz and/or PeCBz rather than the lower chlorinated congeners (Yan et al 2011;Hue et al 2015Hue et al , 2016Hue et al , 2019bLi et al 2016;Balampanis et al 2017;Liu et al 2018;Zhang et al 2018). Studies on detailed compositional profiles of CBzs with different chlorination degrees in waste incinerator ash samples are still relatively scarce (Takaoka et al 2003;Yan et al 2010;Khumsaeng et al 2013;Li et al 2015;Hue et al 2019a). In our previous study, elevated proportions of some di-to tetrachlorinated CBzs were found in several bottom ash and fly ash samples collected from two municipal and four industrial waste incinerators in northern Vietnam (Hue et al 2019a).…”