Classification of coal fly ash based on pH, CaO content, glassy components, and leachability of toxic elements

Author(s):  
Tsugumi Seki ◽  
Yasumasa Ogawa ◽  
Chihiro Inoue
Keyword(s):  
Fly Ash ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 382-391 ◽  
Author(s):  
Masindi Vhahangwele ◽  
Gitari W. Mugera ◽  
Tutu Hlanganani

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.


2020 ◽  
Vol 40 ◽  
pp. 101263
Author(s):  
Luis Monasterio-Guillot ◽  
Pedro Alvarez-Lloret ◽  
Aurelia Ibañez-Velasco ◽  
Alejandro Fernandez-Martinez ◽  
Encarnación Ruiz-Agudo ◽  
...  

1984 ◽  
Vol 47 (1) ◽  
pp. 37-45 ◽  
Author(s):  
D. R. Kalkwarf ◽  
P. O. Jackson ◽  
J. M. Hardin
Keyword(s):  
Fly Ash ◽  

2008 ◽  
Vol 7 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Maria Harja ◽  
Marinela Barbuta ◽  
Lacramioara Rusu ◽  
Nicolae Apostolescu
Keyword(s):  
Fly Ash ◽  

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Kai Yang ◽  
Zejun Tang ◽  
Jianzhang Feng

Sandy soils are prone to nutrient losses, and consequently do not have as much as agricultural productivity as other soils. In this study, coal fly ash (CFA) and anionic polyacrylamide (PAM) granules were used as a sandy soil amendment. The two additives were incorporated to the sandy soil layer (depth of 0.2 m, slope gradient of 10°) at three CFA dosages and two PAM dosages. Urea was applied uniformly onto the low-nitrogen (N) soil surface prior to the simulated rainfall experiment (rainfall intensity of 1.5 mm/min). The results showed that compared with no addition of CFA and PAM, the addition of CFA and/or PAM caused some increases in the cumulative NO3−-N and NH4+-N losses with surface runoff; when the rainfall event ended, 15% CFA alone treatment and 0.01–0.02% PAM alone treatment resulted in small but significant increases in the cumulative runoff-associated NO3−-N concentration (p < 0.05), meanwhile 10% CFA + 0.01% PAM treatment and 15% CFA alone treatment resulted in nonsignificant small increases in the cumulative runoff-associated NH4+-N concentration (p > 0.05). After the rainfall event, both CFA and PAM alone treatments increased the concentrations of NO3−-N and NH4+-N retained in the sandy soil layer compared with the unamended soil. As the CFA and PAM co-application rates increased, the additive effect of CFA and PAM on improving the nutrient retention of sandy soil increased.


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