Effect of different air pollution control devices on the gas/solid-phase distribution of PCDD/F in a full-scale municipal solid waste incinerator. (October 2020)

• Record Type: Journal Article
• Authors: Lin, Xiaoqing; Ma, Yunfeng; Chen, Zhiliang; Li, Xiaodong; Lu, Shengyong; Yan, Jianhua
• Is Part Of: Environmental pollution. Volume 265(2020)Part B
• Publication Date: 2020-10
• Subjects: PCDD/F emission and migration -- Removal efficiency -- Congener distribution -- Memory effect; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114888
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The emission of polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) from full-scale municipal solid waste incinerators (MSWI) is harmful to human and environmental health. This study analyzes the effect of different units of an air pollution control devices (APCDs), i.e. the semi-dry scrubber, fabric filter (FF), selective catalytic reduction (SCR), and wet scrubber (WS), on the removal characteristics and gas- and solid-phase distributions of PCDD/F in MSWI flue gas. APCDs reduce PCDD/F concentrations from 24.9 ng Nm −3 to 0.979 ng Nm −3 (2.16 ng I-TEQ Nm −3 to 0.0607 ng I-TEQ Nm −3 ), with a total removal efficiency (RE) of 96.1% (97.2% I-TEQ). Specifically, APCDs remove more than 95% of both gas- and solid-phase PCDD/F. The FF coupled with active carbon injection (FF + ACI) substantially reduces both gas- and solid-phase PCDD/F concentrations with an RE of 97.2% (98.7% I-TEQ). Additionally, FF + ACI exhibits a better RE of PCDF (98.9%) than PCDD (94.6%) and leads to PCDD congeners dominating the gas-phase. Both desorption and destruction of PCDD/F occur in the SCR, which favors removal of gas-phase PCDD/F but increases solid-phase PCDD/F. Therefore, SCR only decreases PCDD/F with a low RE of 27.6% (16.9% I-TEQ). However, SCR reduces NOx with a high RE of 82.3%, which could inhibit the RE of PCDD/F because of their different reaction mechanisms. WS increases PCDD/F in both the gas and solid-phase by 1.95 times (2.57 times for I-TEQ) due to the memory effect, which typically increases the total mass concentration of PCDD/F and the proportions of lower-chlorinated gas-phase PCDD/F. Migration of gas- and solid-phase PCDD/F are also analyzed according to temperature. The results of this study can contribute to the optimized design of industrial APCDs for controlling PCDD/F emissions from MSWI. Graphical abstract: Image 1 Highlights: Air Pollution Control Devices remove over 95% PCDD/F in both gas- and solid-phase. Fabric filter coupled with active carbon injection better removes PCDF than PCDD. SCR further decreases gas-phase PCDD/F but increases solid-phase PCDD/F. Wet scrubber increases PCDD/F in both gas- and solid-phase due to memory effect.