title: [Novel process utilizing alkalis assisted hydrothermal process to stabilize heavy metals both from municipal solid waste or medical waste incinerator fly ash and waste water].
abstract: An alkalis assisted hydrothermal process was induced to stabilize heavy metals both from municipal solid waste or medical waste incinerator fly ash and waste water. The results showed that alkalis assisted hydrothermal process removed the heavy metals effectively from the waste water, and reduced leachability of fly ash after process. The heavy metal leachabilities of fly ash studied in this paper were Mn 17,300 microg/L,Ni 1650 microg/L, Cu 2560 microg/L, Zn 189,000 microg/L, Cd 1970 microg/L, Pb 1560 microg/L for medical waste incinerator fly ash; Mn 17.2 microg/L, Ni 8.32 microg/L, Cu 235.2 microg/L, Zn 668.3 microg/L, Cd 2.81 microg/L, Pb 7200 microg/L for municipal solid waste incinerator fly ash. After hydrothermal process with experimental condition [Na2CO3 dosage (5 g Na2CO3/50 g fly ash), reaction time = 10 h, L/S ratio = 10/1], the heavy metal removal efficiencies of medical waste incinerator fly ash were 86.2%-97.3%, and 94.7%-99.6% for municipal solid waste incinerator fly ash. The leachabilities of both two kinds of fly ash were lower than that of the Chinese national limit. The mechanism of heavy metal stabilization can be concluded to the chemisorption and physically encapsulation effects of aluminosilicates during its formation, crystallization and aging process, the high pH value has some contribution to the heavy metal removal and stabilization.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. adminwanglei@gmail.com
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Jin
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Chi
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Yan
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D060729:Coal Ash; D004355:Drug Stability; D004787:Environmental Pollution / Q000032:analysis / Q000517:prevention & control; D006358:Hot Temperature; D017745:Incineration; D017744:Medical Waste Disposal / Q000379:methods*; D019216:Metals, Heavy / Q000737:chemistry* / Q000302:isolation & purification; D052638:Particulate Matter / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D000468:Alkalies; D060729:Coal Ash; D017744:Medical Waste Disposal; D019216:Metals, Heavy; D052638:Particulate Matter; D014874:Water Pollutants, Chemical; D002244:Carbon