Leachability of elements from sub-bituminous coal fly ash from India

Praharaj, T.; Powell, M. A.; Hart, Brian; Tripathy, Snehasis

doi:10.1016/s0160-4120(01)00118-0

Cited by 158 publications

(78 citation statements)

References 13 publications

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“…Kim and Kazonich (2004) also reported a dominant silicate association. Pb was found to be highly insoluble and virtually immobile (<1% and often <0.1%) in both acidic and alkaline-natured fly ash samples, irrespective of the pH and the leaching test (Kim et al, 2003;Moreno et al, 2005;Nathan et al, 1999;Praharaj et al, 2002;Ward et al, 2003).…”

Section: Leadmentioning

confidence: 99%

Leaching behaviour of elements from coal combustion fly ash: An overview

Izquierdo

Querol

2012

International Journal of Coal Geology

632

379

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Coal-based power generation produces over 750 Mt of coal ash per year globally, but under 50% of world production is utilised. Large amounts of fly ash are either stored temporarily in stockpiles, disposed of in ash landfills or lagooned. Coal ash is viewed as a major potential source of release of many environmentally sensitive elements to the environment. This paper encompasses over 90 publications on coal fly ash and demonstrates that a large number of elements are tightly bound to fly ash and may not be easily released to the environment, regardless of the nature of the ash. This review provides an extensive look at the extent to which major and trace elements are leached from coal fly ash. It also gives an insight into the factors underlying the leachability of elements and addresses the causes of the mobility. The mode of occurrence of a given element in the parent coal was found to play an important role in the leaching behaviour of fly ash. The amount of calcium in fly ash exerts a dominant influence on the pH of the ash-water system. The mobility of most elements contained in ash is markedly pH sensitive. The alkalinity of fly ash attenuates the release of a large number of elements of concern such as Cd, Co, Cu, Hg, Ni, Pb, Sn or Zn among others, but at the same time, it enhances the release of oxyanionic species such as As, B, Cr, Mo, Sb, Se, V and W. The precipitation of secondary phases such as ettringite may capture and bind several pollutants such ash As, B, Cr, Sb, Se and V.

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Section: Leadmentioning

confidence: 99%

Leaching behaviour of elements from coal combustion fly ash: An overview

Izquierdo

Querol

2012

International Journal of Coal Geology

632

379

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“…CN has been detected at the same level with soil pollution concern criteria of area 2; however the leaching results were not detected. According to the concentration of heavy metals in the coal ash of India, the total chromium concentration is 54 ~ 74 mg/ kg, lead is 84 ~ 182 mg/kg, zinc 29 ~ 44 mg/kg, copper 40 ~ 50 mg/kg, nickel 26 ~ 32 mg/kg [7,8] (Figure 1).…”

Section: Resultsmentioning

confidence: 99%

A Study on Leaching Property of Hazardous Substances in Coal Ash Through the Column Test (Percolation test)

TW¹,

Je²

2016

J Environ Anal Toxicol

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“…In general, the highest contribution to speciation in the char sample is provided by the species in the solution phase. The contribution of organic matter, non-specific adsorption to clay surfaces and the contribution of iron and aluminium (hydr)oxides is minor and only in the case of iron oxide is there a significant binding for Si at pH [8][9][10][11] and for Pb at pH 5-11 ( Figures 3-4).…”

Section: Resultsmentioning

confidence: 99%

“…Trace element mobility in water is particularly pH-dependent [6][7]. Several studies have been focused on the leaching behaviour of toxic elements from fly-and bottom ashes [1,3,[8][9][10], and although it has been established that the leaching of major elements from fly ashes is controlled by solubility, the leaching of trace elements cannot be modelled solely on the basis of this factor [7,11]. For instance, Warren and Dudas (1988) [12] have suggested that adsorption and co-precipitation, especially on secondary minerals, may also affect the partitioning of trace elements between the fly ash and the leachate.…”

Section: Introductionmentioning

confidence: 99%

Leaching of major and trace elements from paper–plastic gasification chars: An experimental and modelling study

Fuente-Cuesta

López-Antón

Dı́az-Somoano

et al. 2013

Journal of Hazardous Materials

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The control of soluble metal species in the sub-product leachate generated in electricity production processes is of great concern from an environmental and health point of view. Unlike fly ash, the leaching behaviour of char materials has received little attention. Yet, these solids are captured together with fly ashes in the particle control devices of power plants and are emitted in the same way as by-products. The present study was carried out using two char samples: i) a raw char and ii) the same type of char employed in a previous study so that it could serve as a sorbent for mercury species in gas phase. The char samples were by-products (residues) that had been generated during the gasification of plastic and paper waste. The leachates were analyzed for the following elements: Al, Ca, Si, Mg, Ba, Cu, Ni, Pb, Zn, Mo and Hg. In addition, geochemical modelling of the leaching test results was employed to identify the underlying chemical processes that led to the release of toxic elements. The results showed that at alkaline pH values, sorption on the solid surfaces of the char was negligible due to the inorganic complexation of cations in the solution. When the char was used as mercury sorbent slight changes occurred on the reactive surface resulting in the modification of the binding of some elements. As the pH increased, complexation with dissolved organic matter played a more important role in the case of some elements such as Cu because of the greater concentration of dissolved organic matter in solution.

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Leachability of elements from sub-bituminous coal fly ash from India

Cited by 158 publications

References 13 publications

Leaching behaviour of elements from coal combustion fly ash: An overview

Leaching behaviour of elements from coal combustion fly ash: An overview

A Study on Leaching Property of Hazardous Substances in Coal Ash Through the Column Test (Percolation test)

Leaching of major and trace elements from paper–plastic gasification chars: An experimental and modelling study

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