Influences of suppression technology on the 2,3,7,8-substituted and non-2,3,7,8-substituted PCDD/Fs from municipal solid waste incinerators

Among all the pollutants emitted from municipal solid waste incinerator (MSWI), dioxins have attracted much attention due to their high toxicity. Meanwhile, MSWI is the second largest dioxin emitter globally. The synergic effects by applying different suppression technologies on both 17 typical 2,3,7,8-dioxins and other non-2,3,7,8-dioxins dioxins from MSWI are quite limited. This study is carried out in two full-scale MSWIs to investigate the coordinate effect of air pollution control devices (APCDs) and calcium-based inhibitor on dioxin. The total suppressing efficiencies of APCDs and inhibitor were 99 %, 74 % for 2,3,7,8-PCDD/Fs and, 96 %, 42 % for non-2,3,7,8-PCDD/Fs, respectively. The mass balance calculation results indicated that waste dominants the input dioxin as 6625 μg I-TEQ/d and fly ash dominants the output dioxin as 97 %, showing a positive mass balance at 7404.5 μg I-TEQ/d. In summary, the APCD and inhibitor can abate the dioxin emitted to the atmosphere but the entire MSWI is a facility that increase the mass of dioxin emitted into the environment especially through fly ash. Different non-2,3,7,8-PCDD/Fs and 2,3,7,8-PCDD/Fs congeners convert between each other through chlorination or dichlorination reactions, is a vital formation route of dioxin that can not to be neglected.