scholarly journals Synthesis of Zeolites from Greek Fly Ash and Assessment of Their Copper Removal Capacity

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 844
Author(s):  
Aikaterini Vavouraki ◽  
Georgios Bartzas ◽  
Konstantinos Komnitsas
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Analytical Techniques ◽  
Copper Removal ◽  
Concerted Action ◽  
Xps Spectra ◽  
Removal Capacity ◽  
Lignite Fly Ash ◽  
Pseudo Second Order ◽  
Second Order Equations

The objective of this study was to synthesize zeolites through fusion of lignite fly ash and NaOH or KOH pellets at 600 °C and assess their removal efficiency in terms of decontamination of solutions containing Cu(II) ions. The removal efficiency of the produced zeolites was tested in batch kinetic experiments using different zeolites and Cu(II) ion concentrations. Experimental data revealed that zeolites synthesized with the use of NaOH exhibited higher removal efficiency compared with those synthesized with the use of KOH. Kinetic data showed that the pseudo-second-order equations described well the removal process. Copper removal was mainly accomplished through the concerted action of chemisorption and intraparticle diffusion. Analytical techniques involving XRF, XRD, FTIR, SEM/EDS and XPS were used for the characterization and morphology analysis of the produced zeolites. SEM/EDS confirmed the presence of copper on the zeolite surface. XPS spectra of Cu2p at 934.3 eV proved the presence of Cu(II) oxidation state, confirming the possible formation of CuO and/or Cu-Cl.

scholarly journals Molybdenum Trioxide: Efficient Nanosorbent for Removal of Methylene Blue Dye from Aqueous Solutions

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Molybdenum Trioxide ◽  
Second Order ◽  
Blue Dye ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Removal Capacity ◽  
Pseudo Second Order

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.

scholarly journals Modified Nigella Sativa Seeds as a Novel Efficient Natural Adsorbent for Removal of Methylene Blue Dye

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1950 ◽  
Author(s):  
Souad Rakass ◽  
Ahmed Mohmoud ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Removal Efficiency ◽  
Ph Value ◽  
Nigella Sativa ◽  
Blue Dye ◽  
Removal Process ◽  
Removal Capacity ◽  
Before And After ◽  
Different Temperatures ◽  
Pseudo Second Order

The aim of this work was to investigate the use of modified nigella sativa seeds (MNS) for removing of methylene blue (MB) dye from aqueous solution. The nigella sativa (NS) seeds have been pre-treated at different temperatures and periods of time. The maximum adsorption of MB was achieved using NS sample washed with distilled water pre-heated at 65 °C for one hour, then ground to 250 µm particle size (MNS-4). Different parameters were modified to optimize the removal process of MB using MNS-4, such as contact times, temperatures, initial dye concentrations, adsorbent doses, and pH of the solution. MNS-4 exhibited a removal efficiency of 99% for initial dye concentrations greater than 800 ppm at pH value of 11. The kinetic study indicated that the removal process follows the pseudo second order model. The removal was spontaneous, endothermic and favorable, and this was indicated by the thermodynamic study. Maximum removal capacity was 194 mg/g as deduced from Langmuir model. The removal efficiency was maintained after four recycle uses. The modified nigella sativa seeds were characterized before, and after adsorption and regeneration by Fourier Transform infrared (FTIR) and scanning electron microscopy (SEM). The data suggested that nigella sativa seeds could be a prospective agent for removing MB from wastewater.

Removal of Pb2+, Cu2+, Ni2+, Cd2+ from Wastewater using Fly Ash Based Geopolymer as an Adsorbent

2018 ◽  
Vol 773 ◽  
pp. 373-378 ◽  
Author(s):  
Sujitra Onutai ◽  
Takaomi Kobayashi ◽  
Parjaree Thavorniti ◽  
Sirithan Jiemsirilers
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Heavy Metal ◽  
Fly Ash ◽  
Surface Area ◽  
Removal Efficiency ◽  
High Efficiency ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Removal Capacity

This work aims to evaluate the effectiveness of fly ash based geopolymer powder as an adsorbent for heavy metals in aqueous solution. The structure of synthesized geopolymer was found to be highly amorphous due to the dissolution of fly ash phase. Moreover, the fly ash geopolymer powder has higher surface area compares to original fly ash with specific surface area of 85.01 m²/g and 0.83 m2/g, respectively. For this reason, the geopolymer powder has much higher removal efficiency compared to the original fly ash powder. The removal efficiency was affected by contact time, geopolymer amount, heavy metal initial concentration, pH, and temperature. The four heavy metals were chosen (Pb2+, Cu2+, Ni2+, Cd2+) for adsorption test. The highest heavy metal removal capacity was obtained at pH 5. The geopolymer powder adsorbed metal cations in the order of Pb2+>Cu2+>Cd2+>Ni2+. In addition, Langmuir model is more suitable for fly ash geopolymer powder adsorption of heavy metal ions in aqueous solution than Freundlich model. The results showed that the fly ash geopolymer powder has high efficiency for removal metal which could be employed excellent alternative for wastewater treatment.

The Adsorption of Cadmium Ions on Fly Ash Based Geopolymer Particles

2018 ◽  
Vol 766 ◽  
pp. 65-70 ◽  
Author(s):  
Sujitra Onutai ◽  
Takaomi Kobayashi ◽  
Parjaree Thavorniti ◽  
Sirithan Jiemsirilers
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Coal Fly Ash ◽  
Bet Surface Area ◽  
Cadmium Ions ◽  
Initial Concentration ◽  
Removal Capacity ◽  
Waste Coal

Geopolymer particles from waste coal fly ash were prepared in order to investigate adsorption process of Cadmium ions. The aim of the study is to focus on factors which affect adsorption process of heavy metals on geopolymer materials. The raw fly ash was mixed with sodium hydroxide solution and sodium silicate solution. After that geopolymer was cured at 80 °C for 24 hr. The sample was ground and washed until pH=7. The obtained geopolymer particles were dried at 60 oC. The raw materials and geopolymer were characterized. The XRD results showed a highly amorphous structure in obtained geopolymer. The major components of waste coal fly ash and synthesized geopolymer were SiO2, Al2O3, Fe2O3 and CaO. The BET surface area of fly ash and geopolymer particles were 0.83 m2/g and 85.01 m2/g, respectively. The adsorption conditions (initial concentration from 10-120 mg/L, temperature at 25-45 °C, pH of cadmium ions solution from 1-5, 0.02-0.14 g. of geopolymer and contact time for 5-180 min) were studied. From removal efficiency results, synthesized geopolymer had high removal capacity for cadmium ions (Cd2+). At pH 5 of solution, the highest Cd2+ removal capacity was obtained. In addition, the removal efficiency increases with an increasing geopolymer dosage, contact time and a decreasing of Cd2+ initial concentration. Moreover, both Langmuir and Freundlich models were investigated for studying adsorption isotherm. The result showed Langmuir model is more suitable for geopolymer adsorption of cadmium ion in aqueous solution than Freundlich model.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

scholarly journals Effect of Lignite Fly Ash on the Growth and Reproduction of Earthworm Eisenia fetida

2009 ◽  
Vol 6 (2) ◽  
pp. 511-517 ◽  
Author(s):  
S. Sarojini ◽  
S. Ananthakrishnasamy ◽  
G. Manimegala ◽  
M. Prakash ◽  
G. Gunasekaran
Keyword(s):  
Fly Ash ◽  
Eisenia Fetida ◽  
Power Plants ◽  
Thermal Power ◽  
Biological Properties ◽  
Cow Dung ◽  
Physical Chemical ◽  
Lignite Fly Ash ◽  
Agricultural Use ◽  
Growth And Reproduction

Fly ash is an amorphous ferroalumino silicate, an important solid waste around thermal power plants. It creates problems leading to environmental degradation due to improper utilization or disposal. However, fly ash is a useful ameliorant that may improve the physical, chemical and biological properties of soils and is a source of readily available plant macro and micronutrients when it is used with biosolids. Supply of nutrients from fly ash with biosolids may enhance their agricultural use. The growth and reproduction ofEisenia fetidawas studied during vermicomposting of fly ash with cowdung and pressmud in four different proportions (T1,T2,T3& T4) and one controli.e.,cow dung and pressmud alone. The growth, cocoon and hatchlings production were observed at the interval of 15 days over a period of 60 days. The maximum worm growth and reproduction was observed in bedding material alone. Next to that the T1was observed as the best mixture for vermiculture.

Phosphorus removal from aqueous solution using a novel granular material developed from building waste

2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen
Keyword(s):  
Granular Material ◽  
Chemical Precipitation ◽  
Phosphate Removal ◽  
Precipitation Process ◽  
Order Kinetic ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.

scholarly journals Insights into Starch Coated Nanozero Valent Iron-Graphene Composite for Cr(VI) Removal from Aqueous Medium

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Prasanna Kumarathilaka ◽  
Vimukthi Jayaweera ◽  
Hasintha Wijesekara ◽  
I. R. M. Kottegoda ◽  
S. R. D. Rosa ◽  
...  
Keyword(s):  
Point Of Zero Charge ◽  
Inert Material ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Graphene Composite ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
First Time

Embedding nanoparticles into an inert material like graphene is a viable option since hybrid materials are more capable than those based on pure nanoparticulates for the removal of toxic pollutants. This study reports for the first time on Cr(VI) removal capacity of novel starch stabilized nanozero valent iron-graphene composite (NZVI-Gn) under different pHs, contact time, and initial concentrations. Starch coated NZVI-Gn composite was developed through borohydrate reduction method. The structure and surface of the composite were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and point of zero charge (pHpzc). The surface area and pHpzc of NZVI-Gn composite were reported as 525 m2 g−1 and 8.5, respectively. Highest Cr(VI) removal was achieved at pH 3, whereas 67.3% was removed within first few minutes and reached its equilibrium within 20 min obeying pseudo-second-order kinetic model, suggesting chemisorption as the rate limiting process. The partitioning of Cr(VI) at equilibrium is perfectly matched with Langmuir isotherm and maximum adsorption capacity of the NZVI-Gn composite is 143.28 mg g−1. Overall, these findings indicated that NZVI-Gn composite could be utilized as an efficient and magnetically separable adsorbent for removal of Cr(VI).

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