scholarly journals Iron-Loaded Carbon Aerogels Derived from Bamboo Cellulose Fibers as Efficient Adsorbents for Cr(VI) Removal

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4338
Author(s):  
Xiaolin Xue ◽  
Wei Yuan ◽  
Zhuo Zheng ◽  
Jian Zhang ◽  
Chenghong Ao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Bulk Material ◽  
Cellulose Fibers ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Ferric Nitrate ◽  
Sem Images ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Kinetics And Isotherms

A unique iron/carbon aerogel (Fe/CA) was prepared via pyrolysis using ferric nitrate and bamboo cellulose fibers as the precursors, which could be used for high-efficiency removal of toxic Cr(VI) from wastewaters. Its composition and crystalline structures were characterized by FTIR, XPS, and XRD. In SEM images, the aerogel was highly porous with abundant interconnected pores, and its carbon-fiber skeleton was evenly covered by iron particles. Such structures greatly promoted both adsorption and redox reaction of Cr(VI) and endowed Fe/CA with a superb adsorption capacity of Cr(VI) (182 mg/g) with a fast adsorption rate (only 8 min to reach adsorption equilibrium), which outperformed many other adsorbents. Furthermore, the adsorption kinetics and isotherms were also investigated. The experiment data could be much better fitted by the pseudo-second-order kinetics model with a high correlating coefficient, suggesting that the Cr(VI) adsorption of Fe/CA was a chemical adsorption process. Meanwhile, the Langmuir model was found to better describe the isotherm curves, which implied the possible monolayer adsorption mechanism. It is noteworthy that the aerogel adsorbent as a bulk material could be easily separated from the water after adsorption, showing high potential in real-world water treatment.

Synthesis of Hematite (α-Fe2O3) Nanostructures by Thermal Oxidation of Iron Sheet for Cr (VI) Adsorption

2018 ◽  
Vol 775 ◽  
pp. 395-401 ◽  
Author(s):  
Christian Laurence E. Aquino ◽  
Mikko James C. Bongar ◽  
Anfernee B. Silvestre ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Water Vapor ◽  
Thermal Oxidation ◽  
Adsorption Process ◽  
Sem Images ◽  
Chromium Ion ◽  
Langmuir Adsorption ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Positively Charged

In this study, hematite (α-Fe2O3) nanostructures were synthesized via thermal oxidation of Fe sheet in dry air and in water vapor. SEM images show nanoblades and nanowires growing on the surface of the sheet. Samples synthesized in water vapor generally produced larger nanostructures while samples oxidized in higher temperatures formed taller and slender nanostructures. The α-Fe2O3nanostructures were used as adsorbent for Cr (VI) in acidic medium. Chromium removal was highest with the samples synthesized at 650°C in water vapor with 95% efficiency. Kinetic and thermodynamic studies revealed that the adsorption process strongly followed pseudo-second order kinetics model and is endothermic. The process also follows the Langmuir adsorption isotherm model, suggesting that the process is described by homogeneous, monolayer adsorption. Adsorption of Cr (VI) onto hematite may be attributed to the electrostatic reaction between the positively charged hematite adsorbent and negative chromium ion.

Adsorption of iron(III), cobalt(II), and nickel(II) on activated carbon derived from Xanthoceras Sorbifolia Bunge hull: mechanisms, kinetics and influencing parameters

2017 ◽  
Vol 75 (8) ◽  
pp. 1849-1861 ◽  
Author(s):  
Xiaotao Zhang ◽  
Yinan Hao ◽  
Ximing Wang ◽  
Zhangjing Chen
Keyword(s):  
Activated Carbon ◽  
Iron Group ◽  
Adsorption Parameters ◽  
X Ray ◽  
Adsorption Capacities ◽  
Adsorption Temperature ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Kinetics And Isotherms

Xanthoceras Sorbifolia Bunge hull activated carbon (XSA) was prepared and characterized by Brunauer–Emmett–Teller analysis, scanning electron microscopy and energy dispersive X-ray (EDX) spectroscopy. The ability of XSA as an adsorbent was investigated for the removal of the iron group ions Fe(III), Co(II), and Ni(II) from aqueous solution. Optimum adsorption parameters were determined based on the initial concentrations of the iron group ions, pH, adsorption temperature, and adsorption time in adsorption studies. The maximum monolayer adsorption capacities were 241.13 mg/g for Fe(III), 126.05 mg/g for Co(II), and 187.96 mg/g for Ni(II), respectively. Adsorption kinetics and isotherms showed that the adsorption process best fitted the nonlinear pseudo-second-order and Langmuir models, and the affinity of the ions for XSA decreased as follows: Fe(III) > Ni(II) > Co(II). Regeneration studies indicated that XSA could be used after several consecutive adsorption/desorption cycles using HNO3. Fourier transform infrared and EDX spectra revealed the chemical adsorption value of XSA as an adsorbent for removing iron group ions from aqueous solutions.

Adsorption Performance of Reactive Red 2BF onto Magnetic NiFe2O4 Nanoparticles Prepared via the Coprecipitation Process

2020 ◽  
Vol 20 (5) ◽  
pp. 2832-2839
Author(s):  
Sha-Sha Li ◽  
Zhou Wang
Keyword(s):  
Adsorption Capacity ◽  
Raw Materials ◽  
Second Order ◽  
Ferric Nitrate ◽  
X Ray Diffraction ◽  
Adsorption Performance ◽  
Transmission Electron ◽  
Monolayer Adsorption ◽  
Coprecipitation Process ◽  
Pseudo Second Order

Magnetic NiFe2O4 nanoparticles were successfully prepared via the coprecipitation process with ferric nitrate, nickel nitrate, and sodium hydroxide as raw materials, and they were characterized by the scanning electron microscopy (SEM), the transmission electron microscope (TEM), the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), the energy dispersive spectroscopy (EDS) and the Brunauer-Emmett-Teller (BET). The magnetic NiFe2O4 nanoparticles were employed to research the adsorption performance of reactive red 2BF (RR-2BF) onto them, and they revealed very large adsorption capacity of RR-2BF. The adsorption kinetics data were evaluated with the pseudo first-order, the pseudo second-order and the intraparticle diffusion models, and the results showed that the pseudo second-order kinetics model was best fitted for the adsorption of RR-2BF onto magnetic NiFe2O4 nanoparticles. While, the adsorption isotherm experiments were carried out at room temperature, and the experimental data conformed to the Langmuir model, which suggested that the adsorption of RR-2BF onto magnetic NiFe2O4 nanoparticles was the monolayer adsorption process. The magnetic NiFe2O4 nanoparticles revealed good reusability, and the adsorption capacity was maintained over 80% of the initial capacity after being used for five cycles.

Competitive Biosorption of Pb(II) and Cu(II) by Functionalised Micropogonias undulates Scales

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Ibrahim O. Tijani ◽  
Oluwaseun J. Ajala ◽  
Fisayo O. Ayandele ◽  
Omodele A. Eletta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Fish Scales ◽  
Wet Impregnation ◽  
Monolayer Adsorption ◽  
Competitive Biosorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Best Fit

Background: Modified bio-based adsorbents from plant sources can be used for pollution remediation by adsorption due to their low cost and availability in large quantities. Objective: In this study, the competitive biosorption of Pb(II) and Cu(II) by Micropogonias undulates functionalised fish scales (FFS) was conducted. The functionalisation was done by wet impregnation with Fe2+. Method: The biosorbent was characterised by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) and Branueur–Emmett–Teller (BET) analyses. Results: The major constituents in the FFS were calcium and phosphorus from the collagen and apatite on the scales. Optimum removal efficiency for both metals was >99% at 10 g/l dosage. It was observed that the Langmuir isotherm model and the pseudo second order kinetics model were the best fit for the experimental data. The monolayer adsorption capacity of FFS for Pb(II) and Cu(II) was observed to be 96.15 mg/g and 100 mg/g respectively. Conclusion: The study revealed that the competitive biosorption of heavy metals can be achieved (at a good adsorption capacity) using functionalised Micropogonias undulates fish scales.

scholarly journals Development of Biochars Derived from Water Bamboo (Zizania latifolia) Shoot Husks Using Pyrolysis and Ultrasound-Assisted Pyrolysis for the Treatment of Reactive Black 5 (RB5) in Wastewater

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1615
Author(s):  
Thanh Tam Nguyen ◽  
Hung-Hsiang Chen ◽  
Thi Hien To ◽  
Yu-Chen Chang ◽  
Cheng-Kuo Tsai ◽  
...  
Keyword(s):  
Cost Effective ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Sem Images ◽  
Zizania Latifolia ◽  
Surface Areas ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ultrasound Assisted ◽  
Green Technique

Adsorbent made by carbonization of biomass under oxygen-limited conditions has become a promising material for wastewater treatment owing to its cost-effective, simple, and eco-friendly processing method. Ultrasound is considered a green technique to modify carbon materials because it uses water as the solvent. In this study, a comparison of Reactive Black 5 (RB5) adsorption capacity between biochar (BC) generated by pyrolysis of water bamboo (Zizania latifolia) husks at 600 °C and ultrasound-assisted biochar (UBC) produced by pyrolysis at 600 °C assisted by ultrasonic irradiation was performed. UBC showed a greater reaction rate and reached about 80% removal efficiency after 4 h, while it took 24 h for BC to reach that level. Scanning electron microscope (SEM) images indicated that the UBC morphology surface was more porous, with the structure of the combination of denser mesopores enhancing physiochemical properties of UBC. By Brunauer, Emmett, and Teller (BET), the specific surface areas of adsorbent materials were analyzed, and the surface areas of BC and UBC were 56.296 m2/g and 141.213 m2/g, respectively. Moreover, the pore volume of UBC was 0.039 cm3/g, which was higher than that of BC at 0.013 cm3/g. The adsorption isotherms and kinetics revealed the better fits of reactions to Langmuir isotherm and pseudo-second-order kinetic model, indicating the inclination towards monolayer adsorption and chemisorption of RB5 on water bamboo husk-based UBC.

scholarly journals Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Thermal Insulation ◽  
Freeze Drying ◽  
Thermal Infrared ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
List Type ◽  
Drying Method ◽  
Cross Sectional ◽  
Compression Resistance

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

Ultramicroporous carbon aerogels encapsulating sulfur as the cathode for lithium–sulfur batteries

2021 ◽  
Author(s):  
Maryam Nojabaee ◽  
Brigitta Sievert ◽  
Marina Schwan ◽  
Jessica Schettler ◽  
Frieder Warth ◽  
...  
Keyword(s):  
Carbon Aerogel ◽  
Composite Cathode ◽  
Microporous Carbon ◽  
Carbon Aerogels ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

In the presented study, a sulfur infiltrated ultra-microporous carbon aerogel as a composite cathode for lithium sulfur batteries is developed and investigated.

scholarly journals Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone–Chitosan–Alginate Nanocomposite from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani
Keyword(s):  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Sem Images ◽  
Bet Analysis ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Multilayer Formation

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.

scholarly journals Light-induced levitation of ultralight carbon aerogels via temperature control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reo Yanagi ◽  
Ren Takemoto ◽  
Kenta Ono ◽  
Tomonaga Ueno
Keyword(s):  
Carbon Nanotubes ◽  
Heat Capacity ◽  
Porous Materials ◽  
Temperature Control ◽  
Light Absorption ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Halogen Lamp ◽  
Absorption Properties ◽  
Air Density

AbstractWe demonstrate that ultralight carbon aerogels with skeletal densities lesser than the air density can levitate in air, based on Archimedes' principle, when heated with light. Porous materials, such as aerogels, facilitate the fabrication of materials with density less than that of air. However, their apparent density increases because of the air inside the materials, and therefore, they cannot levitate in air under normal conditions. Ultralight carbon aerogels, fabricated using carbon nanotubes, have excellent light absorption properties and can be quickly heated by a lamp owing to their small heat capacity. In this study, an ultralight carbon aerogel was heated with a halogen lamp and levitated in air by expanding the air inside as well as selectively reducing its density. We also show that the levitation of the ultralight carbon aerogel can be easily controlled by turning the lamp on and off. These findings are expected to be useful for various applications of aerogels, such as in communication and transportation through the sky.

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