scholarly journals THE EFFECT OF MASS OF COAL FLY ASH-CHITOSAN COMPOSITE PELLETS MODIFIED WITH GLUTARALDEHYDE ON THE ADSORPTION OF MERCURY IN SOLUTION

2017 ◽  
Vol 3 (1) ◽  
pp. 17-19
Author(s):  
Isna Syauqiah ◽  
Umi Baroroh Lili Utami ◽  
Meina Wulansari Yusniar
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Chemical Activation ◽  
Composite Pellet ◽  
Know How ◽  
Physical Chemical ◽  
Low Concentrations ◽  
Composite Pellets ◽  
Chitosan Composite ◽  
Chitosan Gel

Fly ash can be used and utilized as an adsorbent because it is cheap and effective to adsorb waste in the aquatic environment. Hg also known as Mercury is a carciogenic heavy metal and potentially threatens human health at very low concentrations. In this study, fly ash was applied as the adsorbent for Hg2+ in the form of chitosan-fly ash composite pellet and was cross-linked with glutaraldehyde in order to know how much the mass of pellets that can be used to lower the concentration of Hg2+ in solution. The results showed that the fly ash can be compositated with chitosan gel after going through the process of physical-chemical activation so that it can be formed into adsorbent pellets/granules. The optimum condition was obtained from adsorbent pellets of fly ash-chitosan composite crosslinked with glutaraldehyde after contacted with a solution containing Hg2+ with the pellet mass of 3 g.

scholarly journals Physical, chemical, and geotechnical properties of coal fly ash: A global review

2019 ◽  
Vol 11 ◽  
pp. e00263 ◽  
Author(s):  
Arpita Bhatt ◽  
Sharon Priyadarshini ◽  
Aiswarya Acharath Mohanakrishnan ◽  
Arash Abri ◽  
Melanie Sattler ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Geotechnical Properties ◽  
Physical Chemical

Utilization of Atikokan coal fly ash in acid rock drainage control from Musselwhite Mine tailings

2006 ◽  
Vol 43 (3) ◽  
pp. 229-243 ◽  
Author(s):  
H L Wang ◽  
J Q Shang ◽  
V Kovac ◽  
K S Ho
Keyword(s):  
Fly Ash ◽  
Mine Tailings ◽  
Acid Rock Drainage ◽  
Coal Fly Ash ◽  
Alkaline Ph ◽  
Acid Rock ◽  
Physical Chemical ◽  
High Calcium ◽  
A Site ◽  
Accelerated Flow

A site-specific study is carried out to assess the suitability of utilizing Atikokan coal fly ash (AFA) as a buffering material to control and mitigate the generation of acid rock drainage from reactive Musselwhite Mine tailings. The physical, chemical, and mineralogical properties of the fly ash and mine tailings are determined via experiments, followed by six kinetic column permeation tests to monitor the leaching properties of the coal fly ash and coal fly ash – mine tailings mixtures. The results of the experiments indicate that the hydraulic conductivities of high-calcium AFA and the ash–tailings mixtures are significantly reduced upon contact with acidic drainage. The pH of the pore fluid has increased from acidic (pH 4) to alkaline (pH 8 and above). Chemical analyses after the kinetic column permeation tests further indicate that concentrations of regulated elements in the leachate from the ash–tailings mixtures are well below the guideline limits set by the Ontario environmental authority for accelerated flow conditions.Key words: coal fly ash, mine tailings, hydraulic conductivity, pH, heavy metals, acid rock drainage.

scholarly journals Enhanced Desilication of High Alumina Fly Ash by Combining Physical and Chemical Activation

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 411 ◽  
Author(s):  
Yanbing Gong ◽  
Junmin Sun ◽  
Shu-Ying Sun ◽  
Guozhi Lu ◽  
Ting-An Zhang
Keyword(s):  
Activation Energy ◽  
Fly Ash ◽  
Amorphous Phase ◽  
Chemical Activation ◽  
High Alumina ◽  
Side Reactions ◽  
Acid Activation ◽  
Hydrochloric Acid Concentration ◽  
X Ray ◽  
Physical Chemical

In this work, a physical–chemical activation desilication process was proposed to extract silica from high alumina fly ash (HAFA). The effects of fly ash size, hydrochloric acid concentration, acid activation time, and reaction temperature on the desilication efficiency were investigated comprehensively. The phase and morphology of the original fly ash and desilicated fly ash were analyzed by X-ray diffraction (XRD) and scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDS). Compared with the traditional desilication process, the physical–chemical activation desilication efficiency is further increased from 38.4% to 53.2% under the optimal conditions. Additionally, the kinetic rules and equations were confirmed by the experimental data fitting with shrinking core model of liquid–solid multiphase reaction. Kinetic studies show that the enhanced desilication process is divided into two processes, and both steps of the two-step reaction is controlled by chemical reaction, and the earlier stage activation energy is 52.05 kJ/mol and the later stage activation energy is 58.45 kJ/mol. The results of mechanism analysis show that physical activation breaks the link between the crystalline phase and the amorphous phase, and then a small amount of alkali-soluble alumina in the amorphous phase is removed by acid activation, thereby suppressing the generation of side reactions of the zeolite phase.

Cobalt Ion Removal from Aqueous Solutions by Coal Fly Ash

2013 ◽  
Vol 864-867 ◽  
pp. 1732-1740
Author(s):  
Xiao Xu ◽  
Qiang Yang ◽  
Chao Yang Wang
Keyword(s):  
Fly Ash ◽  
Aqueous Solutions ◽  
Removal Rate ◽  
Coal Fly Ash ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Cobalt Ions ◽  
Freundlich Isotherms ◽  
Ion Removal ◽  
Low Concentrations

Cobalt ions, which are commonly found in low concentrations in industrial wastewater, are toxic, biocumulative, and hard to degrade. Therefore, the removal of these heavy metal ions from wastewater is highly important. The removal of Co (II) from aqueous solutions using untreated and alkali-modified coal fly ash was studied. The results for untreated fly ash show that the pseudo-second-order kinetic equation better fits the observed adsorption progress. The Langmuir and Freundlich isotherms could describe the reaction efficiently, and the maximum adsorption capacity for Co (II) was 237 mg·g-1at 20°C. Pretreating the fly ash with an alkali solution decreases the adsorption capability, possibly by destroying the zeolite structure. When the ratio of the fly ash dose and Co (II) concentration is between 40 and 60, the removal rate of Co (II) at a concentration of 20 mg·L-1reaches 99.95%.

UTILIZATION OF COAL FLY ASH FROM POWER PLANTS - I. ASH CHARACTERIZATION

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

scholarly journals Coal Fly Ash and Polyacrylamide Influence Transport and Redistribution of Soil Nitrogen in a Sandy Sloping Land

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Kai Yang ◽  
Zejun Tang ◽  
Jianzhang Feng
Keyword(s):  
Fly Ash ◽  
Sandy Soil ◽  
Coal Fly Ash ◽  
Soil Layer ◽  
Nutrient Retention ◽  
Soil Surface ◽  
Rainfall Event ◽  
N Losses ◽  
N Concentration ◽  
Application Rates

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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