scholarly journals Behavior of bentonite in an aqueous electrolytic solution – evaluation of electrolytic aggregation for adsorption capacity of Cd2+ ions onto bentonite

2018 ◽  
Vol 77 (12) ◽  
pp. 2841-2850
Author(s):  
Ekanayaka Achchillage Ayesha Dilrukshi ◽  
Takeshi Fujino ◽  
Shun Motegi
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Current Density ◽  
Electrolytic Solution ◽  
Clay Particles ◽  
Adsorption Behaviors ◽  
Adsorption Capacities ◽  
Current Densities ◽  
Submerged Area ◽  
Hydrolysis Of

Abstract In this study, we used aqueous solutions containing 1 mg/L of Cd2+ for electrolysis while varying the current density (CD), amount of bentonite added and the effective submerged area to investigate the adsorption capacity of Cd2+ ions onto bentonite by electrolytic aggregation. The adsorption of Cd2+ ions increased with increasing amount of bentonite added to the electrolytic solution. The addition of bentonite also regulated the pH of the electrolytic solution during the electrolysis process in addition to the hydrolysis of water. The maximum adsorption capacities at equilibrium (qe) for current densities of 3.14 and 7.49 mA/cm2 (i.e. for 2 and 1 L electrolytic solutions) with 0.2 g of bentonite were 4.54 and 2.92 mg/g, respectively. The removal of Cd2+ (RCd) clearly depended on the pH of the electrolytic solution. Moreover, qe decreased with increasing amount of bentonite used for electrolytic aggregation. The findings of this study will be useful for understanding the aggregation of clay particles under electrolysis and their adsorption behaviors.

Research of Adsorption Performance of V (V) and Mo (VI) on Collagen Fiber Immobilized Bayberry Tannin

2012 ◽  
Vol 189 ◽  
pp. 69-74
Author(s):  
Wei Hu ◽  
Zhen Zhang ◽  
Hui Yun Liu ◽  
Ru Wang
Keyword(s):  
Adsorption Capacity ◽  
Collagen Fiber ◽  
Rate Model ◽  
Desorption Process ◽  
Adsorption Performance ◽  
Adsorption Behaviors ◽  
Freundlich Equation ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Kinetics Of

The adsorption behaviors of V(V) and Mo(VI) on the collagen fiber immobilized bayberry tannin (IBT), a new kind of adsorption, were investigated. It was found that at 323K, pH=2.0, the adsorption capacities of V(V) on 0.100g adsorbent was 1.03mmol/g in 100ml of 1.960mmol/L V(V) solution, and that of Mo(VI) was 0.86mmol/g at 323K, pH=4.0, with 100ml of 1.042 mmol/L Mo(VI) solution. The effect of pH on the adsorption capacity of V(V) and Mo(VI) was conspicuous. The adsorption capacity of Mo(VI) decreased with pH increasing, and the maximal adsorption capacity of V(V) was observed at pH4.0. Langmuir equation was used for the description of adsorption isotherms of V(V), while Freundlich equation could be well described that of Mo(VI). The adsorption kinetics of V(V) and Mo(VI) can be well described by the pseudo-second-order-rate model and the adsorption capacities calculated by this model are very close to those experimentally determined. The adsorbent can be regenerated by using 0.1mol/L HCl and 0.02mol/L EDTA in tune as desorption agent after the adsorption of V(V) and Mo(VI). In the desorption process V(V) and Mo(VI) were utilized respectively. These facts implies that the adsorbent can be used for the separation of V(V) and Mo(VI) in aqueous.

scholarly journals Comparative Study on the Adsorption Capacities of the Three Black Phosphorus-Based Materials for Methylene Blue in Water

2020 ◽  
Vol 12 (20) ◽  
pp. 8335
Author(s):  
Juanhong Wang ◽  
Zhaocheng Zhang ◽  
Dongyang He ◽  
Hao Yang ◽  
Dexin Jin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Black Phosphorus ◽  
Adsorption Effect ◽  
Adsorption Sites ◽  
Surface Areas ◽  
Adsorption Behaviors ◽  
Adsorption Capacities ◽  
Reduced Graphene ◽  
Black Phosphorene

Dye effluent has attracted considerable attention from worldwide researchers due to its harm and toxicity in recent years; as a result, the treatment for dye has become one of the focuses in the environmental field. Adsorption has been widely applied in water treatment owing to its various advantages. However, the adsorption behaviors of the new materials, such as the 2D black phosphorus (BP), for pollution were urgently revealed and improved. In this work, BP, black phosphorene (BPR), and sulfonated BPR (BPRS) were prepared by the vapor phase deposition method, liquid-phase exfoliating method, and modification with sulfonation, respectively. The three BP-based materials were characterized and used as adsorbents for the removal of methylene blue (MB) in water. The results showed that the specific surface areas (SSAs) of BP, BPR, and BPRS were only 6.78, 6.92, and 7.72 m2·g−1, respectively. However, the maximum adsorption capacities of BP, BPR, and BPRS for MB could reach up to 84.03, 91.74, and 140.85 mg·g−1, which were higher than other reported materials with large SSAs such as graphene (GP), nanosheet/magnetite, and reduced graphene oxide (rGO). In the process of BP adsorbing MB, wrinkles were generated, and the wrinkles would further induce adsorption. BPR had fewer layers (3–5), more wrinkles, and stronger adsorption capacity (91.74 mg·g−1). The interactions between the BP-based materials and MB might cause the BP-based materials to deform, i.e., to form wrinkles, thereby creating new adsorption sites between layers, and then further inducing adsorption. Although the wrinkles had a certain promotion effect, the adsorption capacity was limited, so the sulfonic acid functional group was introduced to modify BPR to increase its adsorption sites and promote the adsorption effect. These findings could provide a new viewpoint and insight on the adsorption behavior and potential application of the BP-based materials.

Adsorption Behaviors of Hydroquinone onto Porous Adsorbents

2012 ◽  
Vol 610-613 ◽  
pp. 1971-1974
Author(s):  
Zeng Yin Zhu ◽  
Bing Li ◽  
Hai Suo Wu ◽  
Wei Liu ◽  
Jin Wei
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Molecular Species ◽  
Adsorption Kinetic ◽  
Adsorption Behaviors ◽  
Low Concentrations ◽  
Porous Adsorbents ◽  
Ph Dependent

As the toxicity even at low concentrations, pollution of phenolic compounds has become an issue of international concern. Adsorption has been proven to be the effective and widely used method for phenolic compounds removal. In this study, porous resins as adsorbents for the removal of hydroquinone from aqueous solutions were evaluated. Activated carbon F400D was employed for comparison. The faster adsorption kinetic was observed on the mesoporous XAD-4, while the higher adsorption capacity was obtained on the microporous NDA150, which had larger surface area. Despite the different surface properties and pore structures of the studied adsorbents, similar trends of pH-dependent adsorption were observed, implying the importance of the hydroquinone molecular species to the adsorption onto the porous adsorbents. This work provided an understanding of adsorption behavior of hydroquinone on porous adsorbents.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

Electron-beam damage of oxides at high current densities

1989 ◽  
Vol 47 ◽  
pp. 634-635
Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Current Density ◽  
Transition Metal Oxides ◽  
Time Resolved ◽  
Rapid Acquisition ◽  
Resolution Electron ◽  
Current Densities ◽  
Electron Stimulated Desorption ◽  
Channel Analyzer

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Adsorption Process ◽  
Sorption Process ◽  
Multiwalled Carbon ◽  
Before And After ◽  
Kinetic Sorption

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

scholarly journals Enhanced Adsorption of Bisphenol A from Aqueous Solution with 2-Vinylpyridine Functionalized Magnetic Nanoparticles

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1136 ◽  
Author(s):  
Qiang Li ◽  
Fei Pan ◽  
Wentao Li ◽  
Dongya Li ◽  
Haiming Xu ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Magnetic Nanoparticle ◽  
Maximum Adsorption Capacity ◽  
Salting Out ◽  
Functionalized Magnetic Nanoparticles ◽  
Ft Ir ◽  
Fe3o4 Nanospheres ◽  
Enhanced Adsorption

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.

scholarly journals Effect of Plating Current Density on the Ball-On-Disc Wear of Sn-Plated Ni Coatings on Cu Foils

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 56
Author(s):  
Ashutosh Sharma ◽  
Byungmin Ahn
Keyword(s):  
Current Density ◽  
Wear Loss ◽  
Wear Properties ◽  
Friction Behavior ◽  
Track Geometry ◽  
Cu Substrates ◽  
Current Densities ◽  
The Impact ◽  
Sliding Distance ◽  
Ball On Disc

Metallic and alloyed coatings are used widely in several decorative and technology-based applications. In this work, we selected Sn coatings plated on Cu substrates for joining applications. We employed two different plating baths for the fabrication of Sn and Ni coatings: acidic stannous sulfate for Sn and Watts bath for Ni layer. The plating current densities were varied from 100–500 mA/cm2. Further, the wear and friction behavior of the coatings were studied using a ball-on-disc apparatus under dry sliding conditions. The impact of current density was studied on the morphology, wear, and coefficient of friction (COF) of the resultant coatings. The wear experiments were done at various loads from 2–10 N. The sliding distance was fixed to 7 m. The wear loss was quantified in terms of the volume of the track geometry (width and depth of the tracks). The results indicate that current density has an important role in tailoring the composition and morphology of coatings, which affects the wear properties. At higher loads (8–10 N), Sn coatings on Ni/Cu had higher volume loss with a stable COF due to a mixed adhesive and oxidative type of wear mechanism.

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