scholarly journals Adsorption of As, B, Cr, Mo and Se from coal fly ash leachate by Fe3+ modified bentonite clay

2015 ◽  
Vol 6 (3) ◽  
pp. 382-391 ◽  
Author(s):  
Masindi Vhahangwele ◽  
Gitari W. Mugera ◽  
Tutu Hlanganani
Keyword(s):  
Fly Ash ◽  
Toxic Elements ◽  
Coal Fly Ash ◽  
Bentonite Clay ◽  
Potentially Toxic Elements ◽  
Subsurface Water ◽  
Modified Bentonite ◽  
Adsorption Affinity ◽  
Adsorbate Concentration ◽  
Five Elements

Fly ash contains the potentially toxic elements As, B, Cr, Mo and Se which upon contact with water may be leached to contaminate surface and subsurface water bodies. This study aims to evaluate the adsorption of these elements from coal fly ash leachates on Fe3+-modified bentonite (Fe-Bent); such modification improved the physicochemical properties of bentonite clay. For optimization of adsorption of the five elements, the effects of time, adsorbent dosage, adsorbate concentration, and pH were optimized. Adsorption affinity of oxyanions followed in the order B = Se > Mo > Cr = As. Experimental data fitted well to Langmuir and Freundlich adsorption isotherms.

Simultaneous sorption of As, B, Cr, Mo and Se from coal fly ash leachates by Al3+-pillared bentonite clay: implication for the construction of activated geo-synthetic clay liner

2017 ◽  
Vol 12 (1) ◽  
pp. 186-201 ◽  
Author(s):  
Vhahangwele Masindi ◽  
W. Mugera Gitari ◽  
Hlanganani Tutu
Keyword(s):  
Fly Ash ◽  
Adsorption Isotherm ◽  
Coal Fly Ash ◽  
Bentonite Clay ◽  
Order Kinetic ◽  
Modified Bentonite ◽  
Adsorption Affinity ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study reports the optimum conditions for intercalating the Al3+ species to bentonite clay matrices and evaluate the potential of using Al3+-modified bentonite clay (Alum-Bent) for removal of oxyanionic species of As, B, Cr, Mo and Se from coal fly ash (FA) leachates. Removal of oxyanionic species was done in batch experimental procedures. Parameters optimized were: contact time, adsorbent dosage, concentration and pH. The adsorption affinity of Al3+-bentonite clay for oxyanionic species varied as follows: B ≈ Se > Mo > Cr ≈ As respectively. The adsorption data fitted better to Langmuir adsorption isotherm than Freundlich adsorption isotherm hence confirming mono-site adsorption. The adsorption kinetics fitted well pseudo-second-order kinetic model hence confirming chemisorption. The fact that most of the oxyanion were adsorbed at pH ≥ pHpzc indicated that both electrostatic and chemical interactions occurred with the clay surface and interlayers. The Al3+-modified bentonite clay successfully removed oxyanion species from generated coal FA leachates. This study shows that Al3+-modified bentonite clay is an effective adsorbent for oxyanion species in coal FA leachates and could be applied as a reactive barrier in coal FA retention ponds.

PAHs and potentially toxic elements in the fly ash and bed ash of biomass fired power plants

2015 ◽  
Vol 132 ◽  
pp. 139-152 ◽  
Author(s):  
Reginald E. Masto ◽  
Elina Sarkar ◽  
Joshy George ◽  
Kumari Jyoti ◽  
Pashupati Dutta ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Toxic Elements ◽  
Potentially Toxic Elements

Adsorption of Iron(II) from Acid Mine Drainage Contaminated Groundwater Using Coal Fly Ash, Coal Bottom Ash, and Bentonite Clay

2016 ◽  
Vol 227 (3) ◽  
Author(s):  
Emelda Obianuju Orakwue ◽  
Varinporn Asokbunyarat ◽  
Eldon R. Rene ◽  
Piet N. L. Lens ◽  
Ajit Annachhatre
Keyword(s):  
Fly Ash ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Coal Fly Ash ◽  
Bottom Ash ◽  
Bentonite Clay ◽  
Contaminated Groundwater ◽  
Coal Bottom Ash ◽  
Acid Mine

LEACHING OF POTENTIALLY TOXIC ELEMENTS FROM ALASKAN STOKER-BOILER FLY ASH

2020 ◽  
Author(s):  
Sarah Hayes ◽  
◽  
Kyle P. Milke ◽  
Kiana Mitchell ◽  
Jennifer Guerard
Keyword(s):  
Fly Ash ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Boiler Fly Ash

scholarly journals CO2 sequestration and simultaneous zeolite production by carbonation of coal fly ash: Impact on the trapping of toxic elements

2020 ◽  
Vol 40 ◽  
pp. 101263
Author(s):  
Luis Monasterio-Guillot ◽  
Pedro Alvarez-Lloret ◽  
Aurelia Ibañez-Velasco ◽  
Alejandro Fernandez-Martinez ◽  
Encarnación Ruiz-Agudo ◽  
...  
Keyword(s):  
Fly Ash ◽  
Co2 Sequestration ◽  
Toxic Elements ◽  
Coal Fly Ash ◽  
Zeolite Production
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