Silicon-aluminum additives assisted hydrothermal process for stabilization of heavy metals in fly ash from MSW incineration

Shi, Dezhi; Hu, Chunyan; Zhang, Jinlu; Li, Pengfei; Zhang, Chao; Wang, Xiaoming; Ma, Hua

doi:10.1016/j.fuproc.2017.05.007

Cited by 49 publications

(27 citation statements)

References 53 publications

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Section: Crystal Phase Analysismentioning

confidence: 95%

“…According to previous studies [26][27][28], the molar ratio of Ca, Al, and Si in the hydrothermal solution made a crucial influence on the final product. When the Al contents were relatively higher, the formation of katoite was promoted [26]. When the Si contents was relatively higher and the molar ratio of Ca/(Al + Si) was in the range of 0.67-1.2, it was more likely to form tobermorite [27,28].…”

Section: Crystal Phase Analysismentioning

confidence: 95%

“…Moreover, the portlandites were detected in Taizhou and Cixi MHP products. It was worth noting that the portlandite was major Ca source for the formation of tobermorite [26]. The content of portlandite in raw Taizhou fly ash and the content of lime in raw Cixi fly ash were very high, and portlandite could be formed by the reaction between lime and water.…”

Section: Crystal Phase Analysismentioning

confidence: 99%

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Stabilization of heavy metals in municipal solid waste circulating fluidized bed incineration fly ash by fusion–hydrothermal method

Chen

Jiang

Zhao

et al. 2019

Waste Dispos. Sustain. Energy

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Municipal solid waste circulating fluidized bed incineration (MSWCFBI) fly ash was a hazardous waste, maintaining challenges for disposal. One effective approach was stabilizing the toxic heavy metal ions in the fly ash structures in situ. This work proposed a fusion-hydrothermal method, including fusion pretreatment in nitrogen atmosphere and microwave-assisted hydrothermal process, to treat three MSWCFBI fly ash samples. Specifically, leaching tests were performed to demonstrate the heavy metal stabilization. Through the treatment of the fusion-hydrothermal process, the concentrations of Cd, Cu, Zn, Pb, Ni, and Cr ions leaching from the fly ashes were obviously less than those of the raw fly ash and the sample only treated by hydrothermal process. Meanwhile, the heavy metal ions migrating from the fly ash to the hydrothermal residual liquid were reduced. Importantly, lots of zeolites formed during the fusion-hydrothermal process, such as to bermorite and sodalite. The fusion pretreatment significantly facilitated the conversion of quartz into amorphous silicon and silicate salts. Then, the silicon dissolution was accelerated and zeolite formation was promoted. Eventually, the heavy metal ions could be trapped in zeolite frameworks, enhancing the stabilization of heavy metal. Moreover, the cation-exchange capability values of the three treated fly ash were 1.099, 1.168, and 1.188 meq g −1 , two-folder larger than those of the samples only treated by hydrothermal process. In summary, the fusion-hydrothermal method could facilitate the stabilization of heavy metal ions in the fly ash and the as-obtained solid product with high content of zeolite was promising for future applications.

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Section: Crystal Phase Analysismentioning

confidence: 95%

Section: Crystal Phase Analysismentioning

confidence: 95%

Section: Crystal Phase Analysismentioning

confidence: 99%

See 1 more Smart Citation

Stabilization of heavy metals in municipal solid waste circulating fluidized bed incineration fly ash by fusion–hydrothermal method

Chen

Jiang

Zhao

et al. 2019

Waste Dispos. Sustain. Energy

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“…Leaching toxicity of all metals met the standard values. [131] "L/S" refers to liquid/solid; "HT" refers to Hydrothermal. HTT has bright development prospects for harmless treatment of MSWIFA.…”

Section: Hydrothermal Treatment (Htt)mentioning

confidence: 99%

Characteristics and Treatment Methods of Medical Waste Incinerator Fly Ash: A Review

et al. 2018

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Medical waste incinerator fly ash (MWIFA) is quite different from municipal solid waste incinerator fly ash (MSWIFA) due to its special characteristics of high levels of chlorines, dioxins, carbon constituents, and heavy metals, which may cause irreversible harm to environment and human beings if managed improperly. However, treatment of MWIFA has rarely been specifically mentioned. In this review, various treatment techniques for MSWIFA, and their merits, demerits, applicability, and limitations for MWIFA are reviewed. Natural properties of MWIFA including the high contents of chlorine and carbonaceous matter that might affect the treatment effects of MWIFA are also depicted. Finally, several commendatory and feasible technologies such as roasting, residual carbon melting, the mechanochemical technique, flotation, and microwave treatment are recommended after an overall consideration of the special characteristics of MWIFA, balancing environmental, technological, economical information.

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“…In addition, the excellent heavy metal adsorption capacity of Al-substituted tobermorite [1,2] made its application broader. In recent years, there are more and more studies on the preparation of autoclaved aerated concrete using iron tailings [3][4][5][6][7] as silicon source, but similarly using municipal solid waste incineration (MSWI) fly ash-containing heavy metals to prepare autoclaved products has been less researched [8,9].…”

Section: Introductionmentioning

confidence: 99%

Utilizing municipal solid waste incineration (MSWI) fly ash as a calcium source to prepare Al‐substituted tobermorite

et al. 2018

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Tobermorite is one of the main products of autoclaved curing concrete. Utilizing of municipal solid waste incineration (MSWI) fly ash as a calcium source to prepare solid waste-based Al-substituted tobermorite was explored. The effects of incorporation of MSWI on the reaction products, compressive strength, microstructure, and pore size distribution of solid waste-based wall materials were studied. The ratio of calcium to silicon (C/S) influenced the formation of Al-substituted tobermorite, and the optimum C/S of the sample without and with MSWI were 1.18 (sample FA-T-(1.18) (FA-T means that fly ash (FA), quick lime, cement, and desulfurization gypsum were used to hydrothermally synthesize solid waste-based Al-substituted tobermorite)) and 1.30 (sample FA-MSWI-T-(1.30) (FA-MSWI-T means that FA, quick lime, MSWI, and desulfurization gypsum were used to hydrothermally synthesize solid waste-based Al-substituted tobermorite)), respectively. Compared with the sample FA-T-(1.18), the compressive strength of FA-MSWI-T-(1.30) increased by 77.5%, the range of main pore size distribution became smaller, and the structure was compact.The microstructure of FA-MSWI-T-(1.30) was fibrous. This work will provide a new way for the utilization of MSWI, which can effectively reduce the pressure on the environment caused by hazardous wastes and provide reference for the basic research on green autoclaved wall materials and heavy metal solidification technology. K E Y W O R D SAl-substituted tobermorite, compressive strength, microstructure, municipal solid waste incineration (MSWI) fly ash, pore size distribution, ratio of calcium to silicon (C/S)

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Silicon-aluminum additives assisted hydrothermal process for stabilization of heavy metals in fly ash from MSW incineration

Cited by 49 publications

References 53 publications

Stabilization of heavy metals in municipal solid waste circulating fluidized bed incineration fly ash by fusion–hydrothermal method

Stabilization of heavy metals in municipal solid waste circulating fluidized bed incineration fly ash by fusion–hydrothermal method

Characteristics and Treatment Methods of Medical Waste Incinerator Fly Ash: A Review

Utilizing municipal solid waste incineration (MSWI) fly ash as a calcium source to prepare Al‐substituted tobermorite

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