Characteristics of PCDD/Fs in Flue Gas from MSWIs and HWIs: Emission Levels, Profiles and Environmental Influence

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the flue gas from two types of waste incinerators (municipal solid waste incinerators and hazardous waste incinerators) the most commonly used in China were investigated in this study. The PCDD/F emissions from the stack gas of the waste incinerators showed a large variation from 0.016 to 0.29 ng I-TEQ m(-3) with an average value of 0.103 ng I-TEQ m(-3). The emission factors of PCDD/Fs were in the range of 0.056-0.607 mu g I-TEQ t(-1) (average 0.235 mu g I-TEQ t(-1)) for municipal solid waste incinerators (MSWIs) and 0.07-3.27 mu g I- TEQ t(-1) (average 1.03 mu g I-TEQ t(-1)) for hazardous waste incinerators (HWIs), respectively. It was estimated that 10.2-88.0 mg I-TEQ (average 35.0 mg I-TEQ) and 1.13-53.0 mg I-TEQ (average 17.1 mg I-TEQ) of PCDD/Fs were annually released to the atmosphere, respectively from MSWIs and HWIs. The level and congener patterns of 17 species of PCDD/Fs in the ambient air and in soil samples around the MSWIs and HWIs were investigated to evaluate the influence of PCDD/F emission on the environment. The PCDD/F concentrations in the ambient air from the 5 MSWIs and 4 HWIs ranged from 0.088 to 13.9 pg I-TEQ m(-3) with an average value of 0.185 pg I-TEQ m(-3). The soil samples in the vicinity of MSWIs and HWIs presented concentrations between 0.68 and 16.0 ng I-TEQ kg(-1) with an average value of 3.98 ng I-TEQ kg(-1). This study showed that PCDD/F emission from the incineration plants had an obvious impact on the surrounding ambient air.