|
|
|
Hydrothermal treatment of MSWI fly ash for simultaneous
dioxins decomposition and heavy metal stabilization |
| Jinlong XIE,Yuyan HU,Dezhen CHEN,Bin ZHOU, |
| Thermal & Environmental
Engineering Institute, Tongji University, Shanghai 200092, China; |
|
|
|
|
Abstract Researches on the hydrothermal treatment of municipal solid waste incineration (MSWI) fly ash were conducted to eliminate dioxins and stabilize heavy metals. In order to enhance decomposing polychlorinated dibenzo-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) during hydrothermal process, a strong reductant carbohydrazide (CHZ) is introduced. A hydrothermal reactor was set up by mixing raw MSWI fly ash or the pre-treated fly ash with water and then heated to a pre-set temperature; CHZ was spiked into solution according to specially defined dosage. Experimental results showed that under the temperatures of 518K and 533K, the decomposition rates of PCDDs/PCDFs were over 80% and 90%, respectively, by total concentration. However, their toxic equivalent (TEQ) decreased only slightly or even increased due to the rising in concentration of congeners 2, 3, 7, 8-TCDD/TCDF, which might be resulted from the highly chlorinated congeners losing their chlorine atoms and being degraded during the hydrothermal process. Better results of TEQ reduction were also obtained under the higher tested temperature of 533K and reactor with addition of 0.1%wt CHZ was corresponded to the best results. Good stabilization of heavy metals was also obtained in the same hydrothermal process especially when ferrous sulphate was added as auxiliary agent.
|
| Keywords
municipal solid wastes incineration (MSWI)
fly ashes
polychlorinated dibenzo-dioxins (PCDDs)
polychlorinated dibenzo-furans (PCDFs)
hydrothermal
heavy metal stabilization
|
|
Issue Date: 05 March 2010
|
|
|
Li X D, Poon C S, Sun H, Lo I M C, Kirk D W. Heavy metal speciation and leaching behavioursin cement based solidified/stabilized waste materials. Journal of Hazardous Materials, 2001, 82(3): 215―230
doi: 10.1016/S0304-3894(00)00360-5
|
|
Mangialardi T, Paolini A E, Polettini A, Sirini P. Optimizationof the solidification/stabilization process of MSW fly ash in cementitiousmatrices, Journal of Hazardous Materials, 1999, 70(1―2): 53―70
doi: 10.1016/S0304-3894(99)00132-6
|
|
Jiang J, Wang J, Xu X, Wang W, Deng Z, Zhang Y. Heavymetal stabilization in municipal solid waste incineration fly ashusing heavy metal chelating agents. Journalof Hazardous Materials, 2004, 113(1―3): 141―146
doi: 10.1016/j.jhazmat.2004.05.030
|
|
Zhao Y C, Song L J, Li G J. Chemical stabilization of MSW incinerator fly ashes. Journal of Hazardous Materials, 2002, 95(1―2): 47―63
|
|
Zhou B, Hu Y Y, Chen D Z. Selection and development of chemical stabilization technologiesfor MSWI fly ash treatment to meet the new landfill standard. Acta Scientiae Circumstantiae, 2009, 29(11): 2372―2377 (in Chinese)
|
|
Weber R, Sakurai T, Hagwnmaier H. Low temperature decomposition of PCDD/PCDF, chlorobenzenesand PAHs by TiO2-based V2O5-WO3 catalysts. Applied Catalysis B: Environmental, 1999, 20(4): 249―256
doi: 10.1016/S0926-3373(98)00115-5
|
|
Yang Z J, Xia C H, Zhang Q, Chen J P, Liang X M. Catalytic detoxification of polychlorinateddibenzo-p-dioxins and polychlorinated dibenzofurans in fly ash. Waste Management, 2007, 27(4): 588―592
doi: 10.1016/j.wasman.2006.02.019
|
|
Yamaguchi H, Shibuya E, Kanamaru Y, Uyama K, Nishioka M, Yamasaki N. Hydrothermal decomposition of PCDDs/PCDFs in MSWI flyash. Chemosphere, 1996, 32(1): 203―208
doi: 10.1016/0045-6535(94)00247-9
|
|
Wang Y J. Study on reaction behaviors between nitrogenous substance and NOxand dioxins in middle-to-high temperature flue gas. Thesis for the master degree. Shanghai: Tongji University, 2008, 25―26
|
|
Wang Z P, Yang S H. Research on New Deoxidants. Application Technology, 2001, 28, (3): 37―39 (in Chinese)
|
|
Sekiguchi Y, Sasaki K, Tanaka S. US Patent, 6483006, 2002-11-19
|
|
Yamasaki N, Sekiyu G. Recycling possibilities oforganic waste by hydrothermal process. Journal of the Japan Petroleum Institute, 1998, 41(3): 175―181
|
|
Youhei M, Kazushi Y, Kazuhiko T, Kyoichi S, Kosuke S. Removal of PCDDs/DFS anddl-PCBs in MWI fly ash by heating under vacuum. Chemosphere, 2006, 64(4): 619―627
doi: 10.1016/j.chemosphere.2005.11.001
|
|
Song G-J, Kim S H, Seo Y-C, Kim S-C. Dechlorinationand destruction of PCDDs/PCDFs in fly ashes from municipal solid wasteincinerators by low temperature thermal treatment, Chemosphere, 2008, 71(2): 248―257
doi: 10.1016/j.chemosphere.2007.09.055
|
|
Brunner G. Nearcritical and supercritical water. Part I. Hydrolytic and hydrothermalprocesses. The Journal of SupercriticalFluids, 2009, 47(3): 373―381
doi: 10.1016/j.supflu.2008.09.002
|
|
Hu Y Y, Chen D Z, Christensen T H. Chemical stabilization of incinerationfly ash with FeSO4 under hydrothermal conditions. Environmental Pollution & Control, 2007, 29(1): 4―8 (in Chinese)
|
|
Astrup T, Rosenblad C, Trapp S, Christensen T H. Chromium release from waste incineration air-pollution-control residues. Environmental Science & Technology, 2005, 39(9): 3321―3329
doi: 10.1021/es049346q
|
|
|
Xiang S F, Yan X S. Inorganic chemistry series:nitrogen. Beijing: Science Press, 1998, 128―132(in Chinese)
|
|
|
|
Lundtorp K, Jensen D L, Sørensen M A, Mosbæk H, Christensen T H. On-site treatment and landfillingof MSWI air pollution control residues, Journal of Hazardous Materials, 2003, B97 (1―3): 59―70
doi: 10.1016/S0304-3894(02)00243-1
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
