Emission levels and phase distributions of PCDD/Fs in a full-scale municipal solid waste incinerator: The impact of wet scrubber system. (20th February 2022)

• Record Type: Journal Article
• Authors: Wang, Pengju; Yan, Feng; Cai, Jianjun; Xie, Feng; Shen, Xuehua; Wei, Xuankun; Yang, Guodong; Zhong, Rigang; Huang, Junbing; Li, Zhongzheng; Zhang, Zuotai
• Is Part Of: Journal of cleaner production. Volume 337(2022)
• Publication Date: 2022-02-20
• Subjects: Municipal solid waste incineration -- Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) -- Wet scrubber -- Phase distribution -- Memory effect; APCDs Air pollutant control devices -- Cmass Mass concentration -- CI-TEQ I-TEQ concentration -- HpCDD Heptachlorodibenzo-p-dioxin -- HpCDF Heptachlorodibenzo-p-furan -- HxCDD Hexachlorodibenzo-p-dioxin -- HxCDF Hexachlorodibenzo-p-furan -- I-TEF International toxic equivalent factors -- I-TEQ International toxic equivalent quantity -- MSW Municipal solid waste -- OCDD Octachlorodibenzodioxin -- OCDF Octachlorodibenzofuran -- PCDD(s) Polychlorinated dibenzo-p-dioxins -- PCDF(s) Polychlorinated dibenzo-p-furans -- PCDD/Fs Polychlorinated dibenzo-p-dioxins and dibenzofurans -- PeCDD Pentachlorodibenzo-p-dioxin -- PeCDF Pentachlorodibenzo-p-furan -- SCR Selective catalytic reduction -- SNCR Selective non-catalytic reduction -- SOx Sulfur oxides -- TCDD Tetrachlorodibenzo-p-dioxin -- TCDF Tetrachlorodibenzo-p-furan -- WSS Wet scrubber system; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.130468
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: The emission of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) from municipal solid waste (MSW) incinerations will pose serious risk to ecological environment and human health. To further understand the memory effect of wet scrubber system (WSS) on PCDD/Fs emission and phase distribution characteristics, a field study was conducted in a full-scale (850 t d −1 ) MSW incinerator where a WSS was newly adopted. The four exhaust flue gas samples and the two scrubbing solution samples inside WSS were separately collected for PCDD/Fs analyzing. The results indicated that the memory effect of WSS obviously enhanced the I-TEQ concentration of PCDD/Fs from 0.007 to 0.033 ng I-TEQ Nm −3 after flue gas passed through WSS, owing to increasing the total mass concentration of PCDD/Fs and the proportion of low-chlorinated congeners. The gas-phase PCDD/Fs was dominant (62.5%–88.9%) in flue gas, among which the PCDD/Fs enriched in condensed water notably contributed to nonnegligible proportions of 25.0%–67.6%. The adsorption/desorption process of PCDD/Fs was considered as one of the reasonable mechanisms of memory effect, based on the PCDD/Fs phase distribution and the congeners profile inside the WSS. Besides, the I-TEQ concentration of PCDD/Fs determined in scrubbing solution was up to 50.2 pg I-TEQ L −1, which might be a potential source to cause the enhancement of PCDD/Fs emission. This study verified the enhancement impact of WSS on PCDD/Fs emission and inspired the optimal design of WSS, i.e., choosing more suitable filling materials and timely replacing them to reduce the negative impact of memory effect, keeping WSS operated in relatively stable and consistent conditions, and safely disposing the scrubbing solution to mitigate the secondary pollution of PCDD/Fs. Graphical abstract: Image 1 Highlights: A field study was conducted on a full-scale MSW incinerator for PCDD/Fs control. Wet scrubber system (WSS) highly enhances the I-TEQ concentration of PCDD/Fs. WSS changes the phase distribution of PCDD/Fs in flue gas owing to memory effect. The shifting rule of PCDD/Fs between flue gas and scrubbing solution is revealed. The migration and transportation pathway of PCDD/Fs congener in WSS is illustrated.