Role of unburnt carbon in adsorption of dyes on fly ash

Wang, Shaobin; Boyjoo, Yashveersingh; Choueib, A.; Ng, Esther; Wu, Hongwei; Zhu, Zhonghua

doi:10.1002/jctb.1299

Cited by 43 publications

(35 citation statements)

References 10 publications

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“…One was commercially available activated carbon and the other was unburned carbon (char carbon), extracted from fly ash. The composition of unburned carbon in fly ash can range from 5 to 15 %, depending on the boiler type (Wang et al 2005). The carbon in fly ash can act as a good sorbent due to its porous structure (developing during the high-temperature combustion process) and large surface areas.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Se (IV) and Se (VI) Using Copper-Impregnated Activated Carbon and Fly Ash-Extracted Char Carbon

Jegadeesan

Mondal

Lalvani

2015

Water Air Soil Pollut

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Surface and groundwater are often contaminated with toxic anions such as arsenic and selenium. Because of their large surface areas, selenium adsorption on carbon sorbents is considered an attractive water treatment technique. In this present work, selenium sorption on copper-impregnated activated carbon and fly ashextracted char carbon was evaluated. Unburned carbon was extracted from fly ash using froth floatation techniques, and the carbon sorbents were modified using copper ions. Adsorption experiments confirmed the strong influence of electrostatic forces on equilibrium uptakes of selenite (Se (IV)) and selenate (Se (VI)). Selenium sorption on virgin char carbon was maximum only at acidic pH, i.e., at pHpH pzc , a two-to fourfold increase in sorption coverage and threefold increase in selenium percent removal was observed. Se (IV) sorption was higher compared to Se (VI) sorption. The effect of selenium concentrations and competing anions was studied to evaluate adsorbent performance. The order of maximum surface coverage followed the order: modified char carbon>modified activated carbon>char carbon. The main mechanism of selenium (Se) sorption appeared to be (1) electrostatic attraction of the Se ions to the modified carbon surface at acidic to neutral pH; (2) complexation of Se ions with the copper ions/oxides on the carbon surface; and (3) co-precipitation with copper hydroxides at alkaline pH.

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Section: Introductionmentioning

confidence: 99%

Adsorption of Se (IV) and Se (VI) Using Copper-Impregnated Activated Carbon and Fly Ash-Extracted Char Carbon

Jegadeesan

Mondal

Lalvani

2015

Water Air Soil Pollut

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“…As a general comment, when the q-values obtained in this work are compared with those published in the literature [7,19,28,37,42], it can be observed that the materials employed here behave in Fig. 8.…”

Section: Adsorption Tests Of CD On Ccamentioning

confidence: 62%

“…Although many papers can be found in the literature on the possibility of removing dyes and heavy metals from wastewaters by adsorption on low-cost activated carbons, the intertwining among waste properties, beneficiation treatments, properties of the beneficiated materials, adsorption mechanisms and efficiencies has only been partly elucidated [37,38]. The aim of this paper is to give a contribution in this direction, by beneficiating CCA in two different ways (mechanical sieving and demineralization) and by carrying out adsorption tests with MB and cadmium.…”

Section: Introductionmentioning

confidence: 99%

Reuse of coal combustion ashes as dyes and heavy metal adsorbents: Effect of sieving and demineralization on waste properties and adsorption capacity

Montagnaro

Santoro

2009

Chemical Engineering Journal

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“…It is the fine grained fraction, collected in the electrofilters and about 60% of it is used in concrete manufacturing (Ahmaruzzaman 2010). Recent studies (Wang et al 2005a(Wang et al , 2005b show that various fly ash samples with different un-burnt carbon contents collected from CPH, can be used for sequential adsorptions of Methylene Blue, Crystal Violet, Methyl Orange, basic dyes and CI Reactive Red 49 in aqueous solution, because the priorities compounds from fly ash favors the heavy metals adsorption and act as active sites in dyes' adsorption processes.…”

Section: Introductionmentioning

confidence: 99%

Concurrent dyes adsorption and photo-degradation on fly ash based substrates

et al. 2010

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Most of the dyes are organic compounds, with different degree of polarization and different groups with various steric effects, making their complete biodegradation slow or even impossible. Adsorption on fly ash and fly ash based substrates represents a possible alternative for simultaneous removal of dyes and heavy metals form wastewaters resulted in the textile industry. Adsorption (under visible light) and adsorption and photodegradation (under UV irradiation) studies were done on Methylene blue solutions and on their mixtures with heavy metals (copper and cadmium), in systems using fly ash as single substrate, or mixed with a wide band gap semiconductor (TiO 2 ). The titanium oxides and hematite content in fly ash proved to be responsible for photodegradation processes even in the absence of the TiO 2 powder, confirming that modified fly ash is a viable candidate in developing up scalable processes for advanced wastewater treatment. The kinetic and thermodynamic studies allow to calculate the parameters and to describe the complex mechanisms, involving competitive adsorption.

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Role of unburnt carbon in adsorption of dyes on fly ash

Cited by 43 publications

References 10 publications

Adsorption of Se (IV) and Se (VI) Using Copper-Impregnated Activated Carbon and Fly Ash-Extracted Char Carbon

Adsorption of Se (IV) and Se (VI) Using Copper-Impregnated Activated Carbon and Fly Ash-Extracted Char Carbon

Reuse of coal combustion ashes as dyes and heavy metal adsorbents: Effect of sieving and demineralization on waste properties and adsorption capacity

Concurrent dyes adsorption and photo-degradation on fly ash based substrates

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