title: Hydrothermal solidification behavior of municipal solid waste incineration bottom ash without any additives.
abstract: Municipal solid waste incineration (MSWI) bottom ash could be solidified with and without slaked lime (calcium hydroxide) addition by a hydrothermal method under steam pressure of 1.56 MPa at 200 °C for up to 72 h. Experimental results showed that CSH gel or tobermorite exerted a main influence on strength development, and without any additives CSH gel was easy to form, while slaked lime addition favored to form tobermorite. Tobermorite seemed to exert a larger effect on the strength development than CSH gel. Leaching results showed that the concentrations of heavy metals dissolved from the solidified specimens were effectively reduced after hydrothermal processing. The immobilization was mainly due to the tobermorite or CSH gel formation, and Pb2+ and Zn2+ seemed to be fixed more readily than Cr6+, which might be the reason that the structural Ca2+ within tobermorite or CSH gel was exchanged by Pb2+ and Zn2+ more easily than Cr6+. In addition, there existed a close relationship between leaching concentration and strength enhancement, and a higher strength seemed to exert a larger effect on immobilization of heavy metals.
authors.affiliation: School of Materials Science and Engineering, Tongji University, Shanghai 201804, China. zzjing@tongji.edu.cn
authors.forename: Zhenzi
authors.initials: Z
authors.lastname: Jing
authors.forename: Xinwei
authors.initials: X
authors.lastname: Fan
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.forename: Junjie
authors.initials: J
authors.lastname: Fan
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Pan
authors.forename: Emile Hideki
authors.initials: EH
authors.lastname: Ishida
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D002126:Calcium Hydroxide / Q000737:chemistry; D060729:Coal Ash; D017745:Incineration; D007854:Lead / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D012037:Refuse Disposal / Q000379:methods*; D017640:Silicates / Q000737:chemistry; D062611:Solid Waste; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015032:Zinc / Q000032:analysis
chemical_list: D017610:Calcium Compounds; D060729:Coal Ash; D019216:Metals, Heavy; D017640:Silicates; D062611:Solid Waste; C512534:tobermorite; D007854:Lead; D015032:Zinc; D002126:Calcium Hydroxide