title: Application of microwave energy in the destruction of dioxins in the froth product after flotation of hospital solid waste incinerator fly ash.
abstract: Most of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and powder-activated carbon (PAC) in hospital solid waste incinerator fly ash are enriched in the froths produced through flotation. Because PAC is an excellent microwave absorber, microwave treatment was performed on the froths in this study to decompose PCDD/Fs. The results showed that the destruction efficiency of PCDD/Fs increased with increasing microwave incident power and processing time, particularly for highly chlorinated PCDD/Fs. With a microwave incident power of 2100W at 7min, the total mass destruction efficiency of the PCDD/Fs in the froths reached 99.6wt.% and the total toxic equivalent (TEQ) of PCDD/F was substantially reduced from 29.0 to 0.08 ng-I-TEQ/g. PCDD/Fs in the froths were mostly decomposed and evaporated very little into exhaust gas under microwave treatment, especially at 2100W. The treated froths displayed good porous structures, enabling the potential recovery of PAC for reuse. Microwave treatment of the froths could promote the rapid decomposition of PCDD/Fs and the recovery of a typical waste resource; also it could present a viable alternative to combustion treatment for the froths.
authors.affiliation: School of Science, Tianjin Chengjian University, 300384 Tianjin, China.
authors.forename: Guo-Xia
authors.initials: GX
authors.lastname: Wei
authors.affiliation: School of Energy and Safety Engineering, Tianjin Chengjian University, 300384 Tianjin, China; Tianjin Key Laboratory of Soft Soil Characteristics and Engineering Environment, 300384 Tianjin, China. Electronic address: lhqlkx@126.com.
authors.forename: Han-Qiao
authors.initials: HQ
authors.lastname: Liu
authors.affiliation: School of Energy and Safety Engineering, Tianjin Chengjian University, 300384 Tianjin, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of Energy and Safety Engineering, Tianjin Chengjian University, 300384 Tianjin, China.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Zhu
authors.affiliation: School of Energy and Safety Engineering, Tianjin Chengjian University, 300384 Tianjin, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Energy and Safety Engineering, Tianjin Chengjian University, 300384 Tianjin, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Zang
keywords: Dioxins; Fly ash; Froths; Microwave treatment; Powder activated carbon