UP-POPs Emissions From Sintering Plants Synergistically Controlled By The Desulfurization Process

The influences of desulfurization systems in sintering plants on polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations, profiles, and emission factors were studied. The respective concentrations of dl-PCB, PCNs, MoCDD/Fs to TrCDD/Fs and tetra-to octa-CDD/F were 290-1906 pg m-3,290-1906 pg m-3,2.1-9.2 ng m-3 and 2.2-28.7 ng m-3 at the inlets. The respective concentrations of dl-PCB, PCNs, MoCDD/Fs to TrCDD/Fs and TeCDD/Fs to OcCDD/Fs were 43.3-500 pg m-3,11988-42245 pg m-3, 0.38-1.67 ng m-3 and 0.29-0.87 ng m-3 after desulfurization. The UP-POPs removal efficiencies achieved by the desulfurization systems were excellent, and the UP-POPs removal efficiencies achieved by desulfurization increased as the chlorination level increased. The total emissions of PCBs and PCNs released to flue gas from the sintering plants were about 30.7 g WHO-TEQ and 394 kg, to gypsum were about 8.07 g WHO-TEQ and 191kg. The total amounts of MoCDD/Fs to TrCDD/Fs emitted in flue gas and gypsum duiring 2003-2012 were 10.7 and 10.2 kg, respectively. The total TEQs emitted in flue gas and gypsum duiring 2003-2012 were estimated to be 15486 and 1878 g I-TEQ, respectively. UP-POPs adsorbed to gypsum are not effectively eliminated. The UP-POPs concentrations increased as the fly ash surface area increased moving through the electrostatic precipitator stages.