Adsorption and Regeneration Characteristics of Granular Adsorbent Based on Coal Fly Ash for Methylene Blue Removal

2013 ◽  
Vol 773 ◽  
pp. 899-906 ◽  
Author(s):  
Jing Wang ◽  
Chang Sheng Peng ◽  
Zhong Fu Yang ◽  
Dan Dan Li ◽  
Yu Ting Wu
Keyword(s):  
Methylene Blue ◽  
Fly Ash ◽  
Adsorption Kinetics ◽  
Coal Fly Ash ◽  
Regeneration Ability ◽  
Initial Ph ◽  
Adsorption Processes ◽  
Regeneration Efficiency ◽  
Adsorption Amount ◽  
Granular Adsorbent

In a previous work, a granular adsorbent based on coal fly ash (GAF) has been prepared and the adsorption amount of methylene blue (MB) reached 278.55mg/g, which is comparable with granular activated carbon. To study its adsorption and regeneration characteristics for MB removal, influencing factors on adsorption, regeneration efficiency, adsorption kinetics and thermodynamics characteristics were investigated. The results indicate that the adsorption amount of MB increased with the increasing of contact time, initial concentration and adsorption temperature, while the initial pH has no significant influence. After 4 times regeneration cycles the regeneration efficiency remains 92% indicating that GAF has desirable regeneration ability. Isothermal studies show that Langmuir and Temkin isothermal models fit the adsorption processes well, indicating that the adsorption should be monolayer adsorption and may existing ion-exchange. Intraparticle diffusion describes the adsorption kinetics processes best. Thermodynamics research reveals the spontaneous and endothermic nature of the adsorption processes.

Adsorption of Methylene Blue and Congo Red on Bentonite Modified with CaCO3

2017 ◽  
Vol 727 ◽  
pp. 853-858 ◽  
Author(s):  
Han Bing Zhang ◽  
Ning Hua Chen ◽  
Zhang Fa Tong ◽  
Qi Feng Liu ◽  
Yan Kui Tang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Isotherms ◽  
Adsorption Kinetics ◽  
Congo Red ◽  
Phosphate Adsorption ◽  
Adsorption Effect ◽  
Adsorption Performance ◽  
Initial Ph ◽  
Removal Efficiencies ◽  
Ph Range

Both bentonite and CaCO3 are cheap and abundant superior regional non-metal ores in Guangxi province, so it is very meaningful to jointly exploit bentonite and CaCO3 for real applications. In this study, bentonite modified with CaCO3 (CCB) was prepared and its adsorption performance of Congo Red (CR) and Methylene Blue (MB) was evaluated by investigating the adsorption influencing effects of initial pH, SDBS and phosphate. Adsorption isotherms and adsorption kinetics models were also fitted to analysis the corresponding kinetic characteristics of CCB. The results show that CCB exhibited superior adsorption performance with the respective > 90% MB and CR removal within the initial pH range 2 ~ 10. To a certain extent, MB removal efficiencies by CCB can be increased with the addition of SDBS. On the other hand, CR adsorption on CCB was inhibited slightly in presence of SDBS. But as a whole, removal efficiencies of MB and CR by CCB were kept constant when SDBS co-existed. MB and CR adsorption on CCB decreased to some extent because of competitive adsorption effect when phosphate co-existed. It also demonstrated that CCB can remove phosphate at the same time with dyes. Adsorption models including adsorption isotherms adsorption kinetics indicated that MB and CR adsorption on CCB was a monolayer process, and the adsorption rate depended on both adsorbent and adsorbate. In summary, CCB is a promising adsorbent for dyes removal with many advantages such as simple preparation technology, excellent adsorption performance for anionic and cationic dyes, broad fitting pH range and SDBS resistance. Besides, it can remove dyes together with phosphate at the same time. Therefore, this study is very useful for the dyeing wastewater treatment and exploiting the resources of bentonite and CaCO3.

scholarly journals Effectiveness of Fly Ash and Red Mud as Strategies for Sustainable Acid Mine Drainage Management

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 707
Author(s):  
Viktoria Keller ◽  
Srećko Stopić ◽  
Buhle Xakalashe ◽  
Yiqian Ma ◽  
Sehliselo Ndlovu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Acid Mine Drainage ◽  
Red Mud ◽  
Mine Drainage ◽  
Ph Value ◽  
Coal Fly Ash ◽  
Precipitation Process ◽  
Acid Mine ◽  
Initial Ph ◽  
Acidic Mine Water

Acid mine drainage (AMD), red mud (RM) and coal fly ash (CFA) are potential high environmental pollution problems due to their acidity, toxic metals and sulphate contents. Treatment of acidic mine water requires the generation of enough alkalinity to neutralize the excess acidity. Therefore, red mud types from Germany and Greece were chosen for the neutralization of AMD from South Africa, where this problem is notorious. Because of the high alkalinity, German red mud is the most promising precipitation agent achieving the highest pH-values. CFA is less efficient for a neutralization and precipitation process. An increase in temperature increases the adsorption kinetics. The maximum pH-value of 6.0 can be reached by the addition of 100 g German red mud at 20 °C to AMD-water with an initial pH value of 1.9. German red mud removes 99% of the aluminium as aluminium hydroxide at pH 5.0. The rare earth elements (yttrium and cerium) are adsorbed by Greek red mud with an efficiency of 50% and 80% at 60 °C in 5 min, respectively.

scholarly journals Adsorptive removal of methylene blue from aqueous solution using coal fly ash-derived mesoporous silica material

2019 ◽  
Vol 37 (3-4) ◽  
pp. 333-348 ◽  
Author(s):  
Ning Yuan ◽  
Hui Cai ◽  
Tian Liu ◽  
Qi Huang ◽  
Xinling Zhang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Fly Ash ◽  
Mesoporous Silica ◽  
Coal Fly Ash ◽  
Nitrogen Adsorption ◽  
Mesoporous Silica Material ◽  
Adsorptive Removal ◽  
Silica Material ◽  
Adsorption Desorption

In the present work, coal fly ash-derived mesoporous silica material (CFA-MS) has been successfully fabricated without employing any extra silica source. The obtained CFA-MS was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption–desorption measurement, powder X-ray diffraction and transmission electron microscopy. Nitrogen adsorption–desorption measurement disclosed that CFA-MS possesses Brunauer–Emmett–Teller-specific surface area of 497 m2·g−1 and pore volume of 0.49 cm3·g−1, respectively. Furthermore, CFA-MS was evaluated for the adsorptive removal of methylene blue from aqueous solution. Several influence parameters on the removal of methylene blue including contact time, pH, initial concentration and temperature were studied in detail. Moreover, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models were employed for interpretation of the adsorption process, while the pseudo-first-order and pseudo-second-order kinetics equations were applied to investigate the adsorption kinetics. Results in the current work demonstrate that CFA-MS can be used as an efficient adsorbent for methylene blue removal.

scholarly journals Enhancing the removal efficiency of methylene blue in water by fly ash via a modified adsorbent with alkaline thermal hydrolysis treatment

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20292-20302
Author(s):  
Nga Thi Dinh ◽  
Linh Ngoc Hoang Vo ◽  
Ngoc Thi Thanh Tran ◽  
Tuan Dinh Phan ◽  
Duc Ba Nguyen
Keyword(s):  
Methylene Blue ◽  
Fly Ash ◽  
Removal Efficiency ◽  
High Efficiency ◽  
Coal Fly Ash ◽  
Thermal Hydrolysis ◽  
Waste Coal

High efficiency of methylene blue adsorbent from waste coal fly ash by treatment with alkaline thermal hydrolysis.

scholarly journals Synthesis and Application of Novel Coal Fly Ash Supported C-Doped TiO2-SnO2 Photocatalytic Nanocomposite for the Removal of Dyes in Water

2020 ◽  
Vol 32 (12) ◽  
pp. 3239-3248
Author(s):  
S. Sambakanya ◽  
P. Nyamukamba ◽  
D.M. Katwire ◽  
H.H. Mungondori ◽  
P. Mukumba ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Fly Ash ◽  
Methyl Orange ◽  
Uv Light ◽  
Sno2 Nanoparticles ◽  
Coal Fly Ash ◽  
Sol Gel ◽  
Carbon Doping ◽  
Solar Irradiation ◽  
Removal Efficiencies

Herein, the preparation, characterization and applications of novel carbon doped titanium dioxide and tin oxide nanocomposite supported on coal fly ash (C-TiO2-SnO2/CFA) are reported. The nanocomposite nanoparticles were successfully synthesized by a sol-gel method and calcined at 550 ºC. XRD analysis showed that SnO2 nanoparticles were polycrystalline in nature and TiO2 had both anatase and rutile phases. Diffuse reflectance spectra showed that carbon doping reduced the band gap of TiO2 from 3.19 eV to 2.78 eV. The nanoparticles′ photocatalytic activity was evaluated using methyl orange and methylene blue dyes, under both UV light and solar irradiation at different pH, pollutant concentration and photocatalyst loading. High photodegradation rates of methyl orange were achieved under visible light. The optimum loading of composite photocatalyst was 0.4 g with removal efficiencies of 97.75% for methyl orange and 99.25% for methylene blue after 3 h. High removal efficiencies were achieved for methyl orange at pH 3 and for methylene blue at pH 10.

UNBURNT CARBON REMOVED FROM FLY ASH BY FLOTATION METHOD

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Rintaro Takehara ◽  
Hiroki Suyama ◽  
Koji Takasu ◽  
Hidehiro Koyamada
Keyword(s):  
Methylene Blue ◽  
Fly Ash ◽  
Fresh Properties ◽  
Efficient Treatment ◽  
Foaming Agent ◽  
Flotation Treatment ◽  
Long Time ◽  
Flotation Method ◽  
Adsorption Amount ◽  
Addition Amount

Because fly ash has pozzolanic activity, it has been used for a long time as an admixture for concrete. However, unburnt carbon in the fly ash adversely affects the fresh properties of concrete. For this reason, when fly ash having a high unburnt carbon content is used as an admixture for concrete, it is desired to reduce the amount of unburnt carbon. So far, at our university, we have developed a technique to remove unburnt carbon by flotation method. It is necessary to add a scavenger and a foaming agent when using this equipment. However, the appropriate amount is unknown. Therefore, we investigated a method to easily estimate the amount of chemicals suitable for flotation treatment from the physical properties of raw fly ash. It is obvious that efficient treatment can be performed when the addition amount of scavenger and the addition amount of foaming agent is set to 10: 1, and that the addition amount of the agent can be accurately estimated by using the methylene blue adsorption amount of fly ash.

scholarly journals Geopolymerization of Coal Fly Ash, Ceramic Tile Waste and Spent Bleaching Earth for the Production of Sodium Aluminosilicate Monolith

2021 ◽  
Vol 333 ◽  
pp. 12001
Author(s):  
Renzo Macasil ◽  
Anne Paulinne Redublo ◽  
Amabelle Santos ◽  
Clark Ivan Torres ◽  
Denvert Pangayao
Keyword(s):  
Methylene Blue ◽  
Compressive Strength ◽  
Fly Ash ◽  
Ceramic Tile ◽  
Coal Fly Ash ◽  
Bleaching Earth ◽  
Mass Ratio ◽  
Sodium Aluminosilicate ◽  
Simple Lattice ◽  
Adsorption Intensity

In this study, compressive strength, density, porosity, and methylene blue adsorptive intensity of sodium aluminosilicate monolith produced from coal fly ash (CFA), ceramic tile waste (CTW), and spent bleaching earth (SBE) were evaluated. Using simple lattice mixture design, CFA-CTW-SBE blend with mass ratio of 55.95% CFA, 38.73% CTW, and 5.31% SBE, and an alkali solution containing 80% 8M NaOH and 20% sodium silicate, resulted to a maximum desirability of 12.4MPa compressive strength, 1310 kg/m3 density, 17.03% porosity, and 1.63% methylene blue adsorption intensity. The properties of the product conform to the specifications of ASTM C90-14 for lightweight load-bearing concrete.

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