title: Evolution of heavy metals in municipal solid waste during bio-drying and implications of their subsequent transfer during combustion.
abstract: Bio-drying has been applied to improve the heating value of municipal solid waste (MSW) prior to combustion. In the present study, evolution of heavy metals in MSW during bio-drying and subsequent combustion was studied using one aerobic and two combined hydrolytic-aerobic scenarios. Heavy metals were concentrated during bio-drying and transformed between different metal fractions, namely the exchangeable, carbonate-bound, iron- and manganese-oxides-bound, organic-matter-bound and residual fractions. The amounts of heavy metals per kg of bio-dried MSW transferred into combustion flue gas increased with bio-drying time, primarily due to metals enrichment from organics degradation. Because of their volatility, the partitioning ratios of As and Hg in flue gas remained stable so that bio-drying and heavy metal speciation had little effect on their transfer and partitioning during combustion. In contrast, the partitioning ratios of Pb, Zn and Cu tended to increase after bio-drying, which likely enhanced their release potential during combustion.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Chang-Lin
authors.initials: CL
authors.lastname: Wu
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
mesh_terms: D000332:Aerobiosis; D000397:Air Pollution / Q000517:prevention & control; D002947:Cities; D003890:Desiccation / Q000379:methods*; D017745:Incineration; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D014835:Volatilization
chemical_list: D019216:Metals, Heavy