Process tracing of PCDD/Fs from economizer to APCDs during solid waste incineration: Re-formation and transformation mechanisms. (1st February 2021)

• Record Type: Journal Article
• Authors: Huang, Yuanqing; Lu, Jia-Wei; Xie, Yingshi; Hong, Chengyang; Shi, Lizheng; Hai, Jing
• Is Part Of: Waste management. Volume 120(2021)
• Page Start: 839
• Page End: 847
• Publication Date: 2021-02-01
• Subjects: Economizer -- PCDD/Fs -- QSAR model -- Interphase transformation -- Removal rate; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2020.11.007
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: PCDD/Fs concentrations decreased by half in the economizer under two conditions. Increasing air supply aggravated formation and emission of PCDD/Fs. Orbital energy factors dE and EH affected PCDD/Fs re-formation. Removal of PCDD/Fs was correlated with vapor pressure and isomer proportion. Stable operation could help to better control dioxin emission. Abstract: The emission of PCDD/Fs is a crucial factor for the aggravation of the Not-In-My-Back-Yard (NIMBY) syndrome, especially for the incineration plants that fail to meet the emission standard. It is well known that physicochemical processes in the boiler can notably affect the discharge of dioxins, especially under transient, non-steady conditions. However, few studies paid attention to the important operational parameters that influence PCDD/Fs formation and transformation in the boiler when an incinerator is in its daily steady operation. In this study, 36 samples were analyzed to achieve process tracing of PCDD/Fs. The concentration, congener profile and vapor/solid partitions of PCDD/Fs from the economizer to air pollution control devices (APCDs) under two typical steady conditions were investigated. Results indicated that increasing air supply aggravated the formation of PCDD/Fs, disturbed the vapor/solid partitions, and triggered a substandard emission. Quantitative structure–activity relationship (QSAR) modeling was firstly performed for the formation mechanism and orbital energy factors were identified as dominating factors. Besides, the removal rates of PCDD/Fs significantly correlated with the saturated vapor pressure and proportions of different isomers. This study is beneficial for operators to optimize relevant operational parameters of the incineration plants so as to get rid of substandard problems.