Removal of chloride from MSWI fly ash

Chen, Wei Sheng; Chang, Full‐Young; Shen, Yun; Tsai, Meng‐Che; Ko, Chun-Han

doi:10.1016/j.jhazmat.2012.08.010

Cited by 101 publications

(44 citation statements)

References 16 publications

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“…In this regard, Yang et al (2012) and Chen et al (2012) have reported that washing methods, involving only water, may be an effective treatment for chloride removal; however, one of the main drawbacks of this treatment is the possible released of large quantities of heavy metals (e.g. Pb and Zn) simultaneously (Quina et al 2008b).…”

Section: Washingmentioning

confidence: 99%

Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation

Margallo

Taddei

Hernández-Pellón

et al. 2015

Clean Techn Environ Policy

122

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Incineration has become an attractive option for municipal solid waste (MSW) management, due to its several benefits. In fact, it allows volume and mass reduction of waste and energy recovery from MSW combustion. Nevertheless, MSW incineration (MSWI) produces three main types of residues: bottom ash (BA), fly ash (FA) and air pollution control (APC) residues, which require an adequate handling. BA is the most significant by-product from MSWI and is generally considered as nonhazardous waste. Instead, FAs are included as hazardous wastes because are characterised by high content of chlorides, heavy metals and organic compounds. The aim of this paper was to examine the characteristics of MSWI solid residues, the management and reuse of these wastes and their environmental assessment from a life cycle perspective. It was noted that the main components that make up the residues are lead and zinc as well as oxides, mainly CaO, SiO 2 and Al 2 O 3 . Furthermore, it is necessary to take into account the presence of PCDD/F which characterised FA and APC residues, mainly due to chlorine content. Chemical and physical properties of those residues make possible their reuse as construction material, as adsorbent, as well as in geotechnical and agricultural applications. Nevertheless, several studies have demonstrated that a drawback of the reuse of MSWI residues is the existence of heavy metals in elevated concentrations which may affect the environmental quality. In this regard, many studies were aimed to assess the environmental impact related to the introduction of MSWI residues as secondary material in several fields of application.

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Section: Washingmentioning

confidence: 99%

Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation

Margallo

Taddei

Hernández-Pellón

et al. 2015

Clean Techn Environ Policy

122

View full text Add to dashboard Cite

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“…By using the roasting treatment, heavy metals can be recycled, and POPs, especially for dioxins, can be effectively decomposed. After detoxification, residual ash can be safely landfill-disposed [90] (Table 6). Researches show that temperature, atmosphere, roasting time, and the type and amount of chlorine medium have an effect on the evaporation rates of heavy metals [91,92].…”

Section: Roastingmentioning

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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“…Obviously, the intensities of the XRD peaks corresponding to easily water-soluble components, such as potassium chloride (KCl) and sodium chloride (NaCl), were all significantly reduced in the XRD spectra of washed ashes. Chen et al [22] indicated that the water-soluble chlorides, such as KCl, NaCl and calcium chloride hydrate (CaCl2•2H2O) are easily washed away from APC residue, but calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach out at room temperature. In Figure 5, no crystalline peaks of CaCl2•2H2O and Ca(OH)Cl were found, implying that they may still be present as amorphous and/or complex crystalline phases.…”

Section: Double and Triple Washingmentioning

confidence: 99%

Leaching Behavior of Circulating Fluidised Bed MSWI Air Pollution Control Residue in Washing Process

et al. 2016

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Abstract:In this study, air pollution control (APC) residue is conducted with water washing process to reduce its chloride content. A novel electrical conductivily (EC) measurement method is proposed to monitor the dynamic change of chloride concentrations in leachate as well as the chloride content of the residue. The method equally applies to various washing processes with different washing time, liquid/solid ratio and washing frequency. The results show that washing effectively extracts chloride salts from APC residues, including those from circulating fluidized bed (CFB) municipal solid waste incineration (MSWI). The most appropriate liquid/solid ratio and washing time in the first washing are found to be around 4 L water per kg of APC residue and 30 min, respectively, and washing twice is required to obtain maximum dissolution. The pH value is the major controlling factor of the heavy metals speciation in leachate, while chloride concentration also affects the speciation of Cd. Water washing causes no perceptible transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from the APC residue to leachate. The chloride concentration is strongly related with electrical conductivity (EC), as well as with the concentrations of calcium, sodium and potassium of washing water. Their regression analyses specify that soluble chloride salts and EC could act as an indirect indicator to monitor the change of chloride concentration and remaining chloride content, thus, contributing to the selection of the optimal washing conditions.

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Removal of chloride from MSWI fly ash

Cited by 101 publications

References 16 publications

Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation

Environmental sustainability assessment of the management of municipal solid waste incineration residues: a review of the current situation

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

Leaching Behavior of Circulating Fluidised Bed MSWI Air Pollution Control Residue in Washing Process

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