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.

Comprehensive diagnosis of PCDD/F emission from three hazardous waste incinerators

“…2,3,4,7,8-PeCDF remains steadily at 40 ± 10% of the total I-TEQ in numerous thermal processes, including iron ore sintering and incineration [ 71 ]. In line with previous investigations on various matrices (flue gas, fly ash, ambient air or soil) in our research group [ 73 – 75 ] and elsewhere [ 13 , 16 ], 2,3,4,7,8-PeCDF was still the most abundant congener in TEQ concentration both during start-up (49.4%) and normal operation (31.4%) at the outlet of the wet scrubber.…”

Suggested guidelines for emergency treatment of medical waste during COVID-19: Chinese experience

“…Zhejiang University has innovatively developed new rotary multi-stage pyrolysis self-melting incineration technology [5][6][7], breaking through the technical bottleneck that has seriously affected continuous and stable operation due to the slagging of the rotary kiln, achieving efficient control and reduction of pollutants emission (especially dioxins) [8,9]. This technology has been applied to 49 hazardous waste pyrolysis incineration treatment projects in 38 cities in 21 provinces of China, with an annual disposal of more than 800,000 tons of hazardous waste, winning the second prize of Chinese National Science and Technology Progress Award in 2017.…”

Emission of unintentionally produced persistent organic pollutants (UPOPs) from municipal waste incinerators in China

“…Recently, a few studies have focused on the emissions of PCBs in other sources, including iron ore sintering plant (Tian et al, 2012), metallurgical process (Nie et al, 2011(Nie et al, , 2012, and medical waste incineration (Chen et al, 2015) in China. Unfortunately, studies on PCB emissions from MWIs in China are extremely limited (Yan et al, 2010).…”