Chemical neutralization of acidic wastes using fly ash in Israel

Polat, Mehmet; Lederman, Eli; Pelly, I.; Cohen, Haim

doi:10.1002/jctb.567

Cited by 18 publications

(11 citation statements)

References 10 publications

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“…Fly ash is a low cost, environment friendly, unconventional and alternative adsorbent for activated carbon (Ceptin and Pehlival, 2007). It can remove different heavy metals from wastewater (Polat et al, 2002;Erol et al, 2005;Heechan et al, 2005). Researchers have reported that it can be used as pretreatment agent as an alternative to dolomite and limestone (Potgieter-Vermaak et al, 2006).…”

Section: Fly Ashmentioning

confidence: 99%

Review on Treatment of Acid Mine Drainage with Waste Materials: A Novel Approach

2018

Global NEST Journal

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<p>The present study systematically and comprehensively reviewed different aspects of treating Acid Mine Drainage (AMD) with active treatment and waste materials. The work also critically reviews the status and the factors associated with the treatment process. Although, conventional active methods are very efficient but they are mainly associated with costly material as well as high maintenance cost which enhances the cost of entire treatment system. Waste materials such as fly ash, metallurgical slag, zero valent iron (ZVI), cement kiln dust (CKD), organic waste such as peat humic agent (PHA) and rice husk can be efficiently used for the treatment of AMD. However, efficiency of different waste material varied from each other due to the variation in their physical and chemical characteristics. The results from the investigation showed that fly ash, metallurgical slag and CKD raise the pH of acidic solution more, in comparison to ZVI and organic waste, due to their richness in lime content. Furthermore, fly ash can be efficiently converted and utilized in its other derivative such as chemically modified fly ash and zeolite. Efficiency of ZVI is hindered by the presence of higher concentration of total dissolved solids. PHA can treat AMD that is mild acidic in nature. Besides, long retention time is required for the removal of heavy metals and sulfur with organic waste and sulfate reducing bacteria (SRB). The study also potentially reviewed that metal removal from AMD varied due to composition of AMD and the characteristics of waste materials. However, waste materials demand more attention for its practical applicability in field conditions due to its richness, higher possibility for recycling and reuse, low installation cost and harmless nature towards the environment.</p>

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Section: Fly Ashmentioning

confidence: 99%

Review on Treatment of Acid Mine Drainage with Waste Materials: A Novel Approach

2018

Global NEST Journal

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“…Studies have shown that fly ash was used to control the production of sulphaterich acid [8] and soil modification [9]. [10] and [11] successfully studied the removal of sulphates from acid mine drainage and acid leachate using fly ash and the research found that the removal was directly proportional to the fly ash CaO content (free lime content in the fly ash). The free lime in fly ash controls the acid generation from wastes as it releases the alkalinity to neutralise the acidity produced.…”

Section: Introductionmentioning

confidence: 99%

Treatment of Sulphate Rich Process Effluents using Coal Fly Ash

2021

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Coal fly ash obtained from a local power station was used as an adsorbent in the removal of sulphates in an aqueous solution. The coal fly ash was characterised using an x-ray fluorescence (XRF) which revealed that it was class C and sub-bituminous type fly ash, an x—ray diffractometer (XRD) which revealed the dominance of a large amorphous phase and a Fourier Transform Infrared Spectroscopy (FTIR) which showed the presence of both organic and inorganic functional groups. Adsorbent dosage, contact time, temperature and solution pH were varied and all the parameters showed a higher uptake of sulphate ions with their increase, except pH which showed a decreasing uptake. The pseudo second order model showed a better fit for the sorption data with lower error values than the pseudo first order model. The uptake of sulphate ions followed both the Langmuir and the Freundlich isotherm models with RL values for the Langmuir within the range 0 < RL < 1 and n-values for the Freundlich within the range 0 < n < 10 showing a favourable sorption for both models. All the thermodynamic parameters (ΔG°, ΔH° and ΔS°) were positive indicating a non – spontaneous, endothermic and a random solid – liquid interface. The process was shown to follow a unimolecular layer approach with chemical adsorption as the dominating mechanism. Generally, coal fly ash showed a higher affinity for sulphates leading to its effective removal.

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“…These authors observed that the coal fly ash controlled the acid generation from the wastes by release of alkalinity over time to the system which neutralized the acidity produced. Several authors have reported on the successful application of coal fly ash for inorganic contaminants removal from AMD and acidic leachates [8,19,30,31]. They observed that contaminants removal was directly proportional to CaO content of the fly ash.…”

Section: Introductionmentioning

confidence: 99%

Treatment of Acid Mine Drainage with Coal Fly Ash: Exploring the Solution Chemistry and Product Water Quality

Gitari¹,

Petrik²,

Akinyemi³

2018

Coal Fly Ash Beneficiation - Treatment of Acid Mine Drainage With Coal Fly Ash

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A treatment process for Acid mine drainage (AMD) using coal fly ash (CFA) was developed. AMD was treated with CFA as the alkaline agent at different CFA: AMD ratios and pH, electrical conductivity (EC) evolution monitored over time. In a separate experiment two AMD sources with differing chemistry were treated with the same CFA to evaluate the impact of AMD chemistry on the treatment process and product water quality. Various CFA: AMD ratios were stirred in a beaker for a pre-set time and the process water chemistry determined. pH was observed to increase in a stepwise manner with buffer zones observed at 4-4.5, 4.5-7 and 6-8. AMD with low concentration of Al 3+ , Fe 2+ , Fe 3+ and Mn 2+ didn't exhibit these buffer zones. Two competing processes were observed to control the evolving pH of process water: dissolution of basic oxides (CaO, MgO) from CFA led to pH increase and hydrolysis of AMD species such as Al 3+ , Fe 2+ , Fe 3+ and Mn 2+ led to pH decrease. These processes initiated mechanisms such as precipitation, adsorption and ion exchange that led to decrease in inorganic contaminants as the treatment progressed. Inorganic contaminants removal was directly related to amount of CFA in reaction media. Precipitation of insoluble hydroxides and Al, Fe-oxyhydroxysulphates contributed to removal of major and minor chemical species. Precipitation of gypsum contributed to removal of sulphate. Na, K and Mg remained largely in solution after initial decrease. Significant leaching of B, Sr, Ba, and Mo from CFA was observed and was directly linked to amount of CFA in the reaction media. This will be a shortcoming of the treatment process since other processes may be required to polish up the product water. The treatment of AMD with CFA was observed to depend on CFA, AMD chemistry, treatment time and might therefore be site specific.

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Chemical neutralization of acidic wastes using fly ash in Israel

Cited by 18 publications

References 10 publications

Review on Treatment of Acid Mine Drainage with Waste Materials: A Novel Approach

Review on Treatment of Acid Mine Drainage with Waste Materials: A Novel Approach

Treatment of Sulphate Rich Process Effluents using Coal Fly Ash

Treatment of Acid Mine Drainage with Coal Fly Ash: Exploring the Solution Chemistry and Product Water Quality

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