Formation, Measurement, and Control of Dioxins from the Incineration of Municipal Solid Wastes: Recent Advances and Perspectives

Abstract

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) consist of 210 kinds of pollutants, 17 of which are highly toxic to humans. PCDD/F is mainly produced during combustion and incineration processes. This review focuses on the formation, measurement, and control of dioxins in municipal solid waste incineration. Typical PCDD/F emission concentrations and air pollutant control devices are introduced in the work. The formation mechanisms of PCDD/F are divided into homogeneous synthesis and heterogeneous synthesis, and some previous reviews and the latest work are introduced. Considering the complexity, high cost, and time lag of traditional offline detection methods based on high-resolution gas chromatography coupled with high-resolution mass spectrometry, fast and indirect measurement techniques have been recently developed, among which resonance-enhanced multiphoton ionization-time-of-flight mass spectrometry is a good option. The study of online/at-line in situ measurements and the correlation between PCDD/F and the indicator are reviewed in detail. Due to the strict policies regarding pollutants’ emissions, state-of-the-art remediation technologies are used to reduce dioxin formation and emission from incineration. A comprehensive discussion about the control of dioxin emission is also reviewed in this work. Finally, challenges, future directions, and perspectives are proposed.

Revealing the Mechanism of Dioxin Formation from Municipal Solid Waste Gasification in a Reducing Atmosphere

“…40 However, the incomplete combustion of MSW might produce residual carbon, which will serve as the carbon source and reaction sites to accelerate both de novo synthesis and heterogeneous formation of the precursor for dioxins. 41 By comparing three different types of gasification agents (O 2 / H 2 O/CO 2 ), introducing CO 2 would decrease the dioxin concentration by 80% compared to the incineration condition. It was assumed the addition of CO 2 promoted the reforming reaction of CO 2 (T3 and T4) and generated more reducing gases like H 2 and CO.…”

“…It was because the amount of residual carbon in fly ash was reduced substantially due to complete burning of MSW within an oxygen-rich atmosphere, leading to a dramatic decrease of solid-phase dioxin formation . However, the incomplete combustion of MSW might produce residual carbon, which will serve as the carbon source and reaction sites to accelerate both de novo synthesis and heterogeneous formation of the precursor for dioxins . By comparing three different types of gasification agents (O 2 /H 2 O/CO 2 ), introducing CO 2 would decrease the dioxin concentration by 80% compared to the incineration condition.…”

Contamination characteristics, coexistence relationships and health risk assessment of dioxins and metals in topsoil around municipal solid waste incinerator in Hainan, China

“…Furthermore, the findings indicate that the coexisting metals and dioxin homologs may have similar distribution characteristics and sources. Therefore, monitoring the specific metals (e.g., Sb, Cd, Zn and Pb) may help describe the distribution of dioxins in soils (Bo et al, 2022) and address the difficulties of traditional dioxin monitoring methods (e.g., high measurement costs and technical requirements) (Peng et al, 2020). However, this finding needs to be further confirmed by laboratory mechanism analysis, comprehensively considering the chemical and biological interactions of pollutants, and the effects of other factors (e.g., soil organic matter content and MSW type) (Zhang et al, 2020;Yuan et al, 2021).…”

Virtual Special Issue of Recent Research Advances in China: Thermochemical Processing of Biomass and Solid Wastes

“…Zhang et al 7 systematically summarize the causes and mechanisms of corrosion on heat transfer tubes during the combustion of low-grade solid fuels and present the status and prospectives of the application of coatings to alleviate fireside corrosion. Peng et al 8 provide a comprehensive review of the formation, measurement, and control of dioxins during the incineration of municipal solid wastes. Liu et al 9 systematically summarize the current status of the co-combustion technology of organic solid wastes (OSWs) and coal in China, providing the guidelines for further applications of OSWs in stationary power plants.…”