title: Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations.
abstract: Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na2S and Na2SO4) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na2SO4 and Na2S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO4(s) at low temperatures (<1000 K). The equilibrium calculation prediction also suggested that SiO2, CaO, TiO2, and Al2O3 containing materials function as condensed phase solids in the temperature range of 800-1100 K as sorbents to stabilize Pb. However, in the presence of sulfur or chlorine or the co-existence of sulfur and chlorine, these sorbents were inactive. The effect of sulfur on Pb partitioning in the sludge incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the concentration of Si, Ca and Al-containing compounds in the sludge. These findings provide useful information for understanding the partitioning behavior of Pb, facilitating the development of strategies to control the volatilization of Pb during sludge incineration.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: www053991@126.com.
authors.forename: Jing-yong
authors.initials: JY
authors.lastname: Liu
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Shu-jie
authors.initials: SJ
authors.lastname: Huang
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Shui-yu
authors.initials: SY
authors.lastname: Sun
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Xun-an
authors.initials: XA
authors.lastname: Ning
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Rui-zhe
authors.initials: RZ
authors.lastname: He
authors.affiliation: Guangdong Testing Institute of Product Quality Supervision, Guangzhou 510330, China.
authors.forename: Xiao-ming
authors.initials: XM
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Guang-qian
authors.initials: GQ
authors.lastname: Luo
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Wu-ming
authors.initials: WM
authors.lastname: Xie
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Zhong-xu
authors.initials: ZX
authors.lastname: Zhuo
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
authors.forename: Jie-wen
authors.initials: JW
authors.lastname: Fu
mesh_terms: D002681:China; D002947:Cities; D060729:Coal Ash / Q000032:analysis; D017745:Incineration; D007854:Lead / Q000737:chemistry*; D008962:Models, Theoretical; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D013457:Sulfur Compounds / Q000737:chemistry; D013816:Thermodynamics; D014835:Volatilization; D018505:Waste Management
chemical_list: D060729:Coal Ash; D012722:Sewage; D013457:Sulfur Compounds; D007854:Lead; D013455:Sulfur
keywords: Lead (Pb); Sludge incineration; Sulfur; Thermodynamic equilibrium calculation; Volatilization