title: Evaluation of PCDD/Fs and metals emission from a circulating fluidized bed incinerator co-combusting sewage sludge with coal.
abstract: The emission characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and heavy metals were evaluated during co-combustion of sewage sludge with coal from a circulating fluidized bed incinerator. The stack gas, slag and fly ash samples were sampled and analyzed. The gas-cleaning system consisted of electrostatic precipitators and a semi-dry scrubber. Results showed that the stack gas and fly ash exhibited mean dioxin levels of 9.4 pg I-TEQ/Nm3 and 11.65 pg I-TEQ/g, respectively, and showed great similarities in congener profiles. By contrast, the slag presented a mean dioxin level of 0.15 pg I-TEQ/g and a remarkable difference in congener profiles compared with those of the stack gas and fly ash. Co-combusting sewage sludge with coal was able to reduce PCDD/Fs emissions significantly in comparison with sewage sludge mono-combustion. The leaching levels of Hg, Pb, Cd, Ni, Cr, Cu, and As in the fly ash and slag were much lower than the limits of the environmental protection standard in China. These suggest that the co-combustion of sewage sludge and coal is an advisable treatment method from an environmental perspective.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China. z.gang02@mail.scut.edu.cn
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Hai
authors.forename: Jiang
authors.initials: J
authors.lastname: Cheng
authors.forename: Zhiqi
authors.initials: Z
authors.lastname: Cai
authors.forename: Mingzhong
authors.initials: M
authors.lastname: Ren
authors.forename: Sukun
authors.initials: S
authors.lastname: Zhang
authors.forename: Jieru
authors.initials: J
authors.lastname: Zhang
mesh_terms: D001572:Benzofurans / Q000032:analysis*; D002104:Cadmium / Q000032:analysis; D003300:Copper / Q000032:analysis; D000072338:Dibenzofurans, Polychlorinated; D007854:Lead / Q000032:analysis; D008628:Mercury / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D009532:Nickel / Q000032:analysis; D012722:Sewage
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D019216:Metals, Heavy; D012722:Sewage; D002104:Cadmium; D007854:Lead; D003300:Copper; D009532:Nickel; D008628:Mercury