title: Dioxins from medical waste incineration: Normal operation and transient conditions.
abstract: Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are key pollutants in waste incineration. At present, incinerator managers and official supervisors focus only on emissions evolving during steady-state operation. Yet, these emissions may considerably be raised during periods of poor combustion, plant shutdown, and especially when starting-up from cold. Until now there were no data on transient emissions from medical (or hospital) waste incineration (MWI). However, MWI is reputed to engender higher emissions than those from municipal solid waste incineration (MSWI). The emission levels in this study recorded for shutdown and start-up, however, were significantly higher: 483 ± 184 ng Nm(-3) (1.47 ± 0.17 ng I-TEQ Nm(-3)) for shutdown and 735 ng Nm(-3) (7.73 ng I-TEQ Nm(-3)) for start-up conditions, respectively. Thus, the average (I-TEQ) concentration during shutdown is 2.6 (3.8) times higher than the average concentration during normal operation, and the average (I-TEQ) concentration during start-up is 4.0 (almost 20) times higher. So monitoring should cover the entire incineration cycle, including start-up, operation and shutdown, rather than optimised operation only. This suggestion is important for medical waste incinerators, as these facilities frequently start up and shut down, because of their small size, or of lacking waste supply. Forthcoming operation should shift towards much longer operating cycles, i.e., a single weekly start-up and shutdown.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Ming-xiu
authors.initials: MX
authors.lastname: Zhan
authors.affiliation: Institute of energy and power engineering, Zhejiang University of Technology, Hangzhou, P.R. China yanmi1985@zjut.edu.cn.
authors.forename: Mi
authors.initials: M
authors.lastname: Yan
authors.affiliation: China United Engineering Corporation, Hangzhou, P.R. China.
authors.forename: Jian-ying
authors.initials: JY
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Sheng-yong
authors.initials: SY
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P.R. China.
authors.forename: Alfons
authors.initials: A
authors.lastname: Buekens
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002681:China; D004147:Dioxins / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring; D017745:Incineration; D008506:Medical Waste / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D004147:Dioxins; D008506:Medical Waste
keywords: Medical waste incineration; dioxins (PCDD/Fs); memory effects; poor combustion; shutdown; start-up