scholarly journals LDH-Co-Fe-Acetate: A New Efficient Sorbent for Azoic Dye Removal and Elaboration by Hydrolysis in Polyol, Characterization, Adsorption, and Anionic Exchange of Direct Red 2 as a Model Anionic Dye

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3183
Author(s):  
Nawal Drici-Setti ◽  
Paolo Lelli ◽  
Noureddine Jouini
Keyword(s):  
Heating Temperature ◽  
Acetate Anion ◽  
Anionic Dyes ◽  
Adsorption Processes ◽  
Polyol Medium ◽  
Forced Hydrolysis ◽  
Important Amount ◽  
High Level ◽  
Double Hydroxide ◽  
New Phase

A new, double hydroxide based on Co and Fe was elaborated on by forced hydrolysis in a polyol medium. Complementary characterization techniques show that this new phase belongs to the layered double hydroxide family (LDH) with Co2+ and Fe3+ ions located in the octahedral sites of the bucite-like structure. The acetate anions occupy interlayer space with an interlamellar distance of 12.70 Å. This large distance likely facilitates the exchange reaction. Acetates were exchanged by carbonates. The as-obtained compound Co-Fe-Ac/Ex shows an interlamellar distance of 7.67 Å. The adsorption of direct red 2 by Co-Fe-Ac-LDH has been examined in order to measure the capability of this new LDH to eliminate highly toxic azoic anionic dyes from waste water and was compared with that of Co-Fe-Ac/Ex and Co-Fe-CO3/A (synthesized in an aqueous medium). The adsorption capacity was found to depend on contact time, pH, initial dye concentration, and heating temperature. Concerning CoFeAc-LDH, the dye uptake reaches a high level (588 mg/g) due to the occurrence of both adsorption processes: physisorption on the external surface and chemical sorption due to the intercalation of dye by exchange with an acetate anion. The study enables us to quantify the uptake amount of each effect in which the intercalation has the most important amount (418 mg/g).

Hybrid Pigments Based on Montmorillonite and Anionic Dyes for Leather Finishing

2021 ◽  
Vol 320 ◽  
pp. 198-203
Author(s):  
Anna Bondaryeva ◽  
Olena Mokrousova ◽  
Olena Okhmat
Keyword(s):  
Maximum Level ◽  
Steric Factor ◽  
Anionic Dyes ◽  
Mineral Particles ◽  
High Level ◽  
Leather Finishing ◽  
Positively Charged ◽  
Sodium Form

The work is focused on obtaining hybrid pigments by adsorption of anionic dyes on positively charged montmorillonite. Modification of the sodium form of montmorillonite by chromium hydroxocomplexes was provided to ensure effective adsorption of anionic dyes on the surface of mineral particles. A high level of adsorption of anionic dyes as a result of steric factor was revealed. It was shown that the adsorption of dyes depended on the pH of the medium and was characterized by a maximum level at pH 4.5 – 6.0. The scheme of obtaining hybrid pigments, which were characterized by good сovering ability, resistance to stratification, especially saturated and intense colour was proposed.

Characterization and Evaluation of Ca/Al LDHs Adsorbents Synthesized by a One-Step Hydrothermal Method for Congo Red Removal

2020 ◽  
Vol 977 ◽  
pp. 195-200
Author(s):  
Hong Tham Thi Nguyen ◽  
Dao Thi To Uyen ◽  
Duy Chinh Nguyen ◽  
Van Thuan Tran ◽  
Tri Duc Lam ◽  
...  
Keyword(s):  
Congo Red ◽  
Fourier Transforms ◽  
X Ray Diffraction ◽  
Anionic Dyes ◽  
One Step ◽  
Ft Ir ◽  
Fourier Transforms Infrared Spectroscopy ◽  
Hydrothermal Approach ◽  
Double Hydroxide ◽  
Hydrolysis Of

We investigated the fabrication of Ca/Al layered double hydroxide (LDHs) via a one-step hydrothermal approach with slow hydrolysis of urea at a low temperature without further annealing required. The as-synthesized Ca/Al LDHs nanostructures obtained were defined using Fourier transforms infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that Ca/Al LDHs exhibit excellent adsorption performance on Congo red anionic dyes in aqueous solution. The adsorption capacity of the Ca/Al LDHs toward Congo red was found to be 59.41 mg/g.

Heat Treatment Effect on Properties of Al-Mg-Si-Cu 1370 Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 519-524 ◽  
Author(s):  
N.I. Kolobnev ◽  
L.B. Khokhlatova ◽  
S.V. Samokhvalov ◽  
A.A. Alekseev ◽  
S.V. Sbitneva ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heating Temperature ◽  
Solution Treatment ◽  
Phase Relationship ◽  
Dark Field ◽  
Intercrystalline Corrosion ◽  
Quenching Rate ◽  
Heat Treatment Regimes ◽  
Alloy Properties ◽  
High Level

The Russian 1370 Al-Mg-Si-Cu alloy (analogue of 6056) is an advanced material for the skin and stringers of fuselage. However, these alloys are susceptible to the intercrystalline corrosion depending on the heat treatment regimes. The investigations of the effect of heating temperature during the solid solution treatment (530-555)°C and quenching rate, ageing regimes and interval between the quenching and ageing on the structure and properties of 1370 alloy sheets were performed. The strengthening β (Mg2Si) -phase and Q (Al5Cu2Mg8Si6) -phase relationship dependence of the alloy properties is established. Using the dark field electron microscopy which permits to intensify separate diffraction reflexes of strengthening phases the structure of Q-phase precipitates has been studied. Optimization of heat treatment of 1370 alloy sheets provided the combination of fracture toughness characteristic (Kco= 100 MPa√m) high level, the ultimate strength of 400-420 MPa and intercrystalline corrosion no more 100 μm in depth.

scholarly journals EDITORIAL

2015 ◽  
Vol 12 (2) ◽  
pp. 151-155
Author(s):  
GEOFFREY BURGESS
Keyword(s):  
Early Music ◽  
Music Training ◽  
The Past ◽  
Look Back ◽  
The World ◽  
Short Space ◽  
High Level ◽  
New Phase

The passing of pioneering figures – musicians Christopher Hogwood, Frans Brüggen, Gustav Leonhardt and Bruce Haynes, as well as harpsichord builder Martin Skowroneck and flute maker and recording engineer Andreas Glatt – all in the short space of the past couple of years might suggest that early music has reached its end, or at least entered a new phase. As we look back over the past forty-five years since the term ‘early music’ was trademarked in England by Early Music Shop founder Richard Wood, we may well ask if the movement's function and goals remain the same. Early music, which initially rode on the tailcoats of counterculture and actively disparaged the mainstream, has reached a high level of professionalism, and more than anything has become institutionalized. It now forms part of music training in conservatories around the world, as early-instrument orchestras proliferate and opera companies are increasingly turning to pre-romantic opera. For some, the professionalization of early music is an indication of its far-reaching impact, but to others the price paid is only too evident.

scholarly journals Powder and film of nickel and iron-layered double hydroxide: Elaboration in polyol medium and characterization

2008 ◽  
Vol 69 (5-6) ◽  
pp. 1052-1055 ◽  
Author(s):  
M. Taibi ◽  
S. Ammar ◽  
F. Schoenstein ◽  
N. Jouini ◽  
F. Fiévet ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Polyol Medium ◽  
Double Hydroxide

An Investigation on Anti-reducing Effect of CaO in Barium Titanate Based Ceramic

2011 ◽  
Vol 239-242 ◽  
pp. 2457-2460
Author(s):  
Sen Wang ◽  
Zhi Hui Li ◽  
Xin Liu ◽  
Huan Zhang
Keyword(s):  
Liquid Phase ◽  
Barium Titanate ◽  
Phase Formation ◽  
Film Formation ◽  
Ceramic Materials ◽  
Structure Development ◽  
Sintering Aid ◽  
Reducing Atmosphere ◽  
High Level ◽  
New Phase

Anti–reducing effect of CaO in barium titanate based ceramic materials sintered at reducing atmosphere and the structure development of the materials has been studied in this paper.The results show: Addition of CaO in barium titanate based ceramic will keep resistivity of the sample sintered at reducing atmosphere at a high level. The resistivity of the materials increase with the increasing of CaO, and the resistivity keep in constant after the amount of CaOexcess 3mol%. In the sample with sintering aid of SiO2and BaO-excess, introducing of CaO may improve the resistivity of the materials obviously. A slight new phase formation was found in the BaO-excess sample, but no new phase formation was found in the non BaO-excess sample. If there is sintering aid of SiO2in the sample, CaO may accelerate liquid phase film formation at the surface of grains, which will suppress the diffusion of oxygen in the grains to the environment.

scholarly journals Adsorption of Orange II Onto Zn2Al–Layered Double Hydroxide Prepared From Zinc Ash

2020 ◽  
Vol 8 ◽  
Author(s):  
Andra Tǎmaş ◽  
Ioana Cozma ◽  
Laura Cocheci ◽  
Lavinia Lupa ◽  
Gerlinde Rusu
Keyword(s):  
Layered Double Hydroxide ◽  
Structural Characteristics ◽  
Dye Adsorption ◽  
Treatment Method ◽  
Orange Ii ◽  
Efficient Treatment ◽  
Secondary Sources ◽  
Adsorption Processes ◽  
Zinc Ash ◽  
Double Hydroxide

The dye industry is one of the largest water consuming industries, and at the same time generates large quantities of wastewaters. The resulting wastewaters require proper treatment before discharge, because the dye contents have a negative effect on the water body and organisms present in it. The most efficient treatment method for water containing dyes is represented by adsorption processes. The challenge with these adsorption processes is to develop new, efficient, viable, and economic adsorbent materials. Therefore, in the present paper, the performance of Zn2Al-layered double hydroxide, prepared from an industrial waste (zinc ash) as a zinc source, was investigated in the Orange II dye adsorption process. The Zn2Al-layered double hydroxide prepared from secondary sources presents similar morphological and structural characteristics as those prepared from analytical grade reagents. The influence of initial dye concentration, adsorption time, solid:liquid ratio, pH, and temperature was evaluated in order to confirm the benefit of this waste valorization. A comparison with the reference Zn2Al-layered double hydroxide prepared from analytical grade reagents was performed and the results show that due to the small presence of impurities, the material prepared from zinc ash shows better adsorption capacities (qmax,exp = 42.5 mg/g at 293 K) than the material prepared from reagents (qmax,exp = 36.9 mg/g at 293 K), justifying the utilization of secondary sources for layered double hydroxides preparation. The proposed treatment process presents advantages from both economic and environmental protection point of view.

scholarly journals Participation engineer M.L. Schukin in the design and construction of the imperial train foreign and homeland track

2016 ◽  
Vol 6 (9) ◽  
pp. 55-71
Author(s):  
M. Povisshaya
Keyword(s):  
Developed Countries ◽  
Railway Transport ◽  
Scientists And Engineers ◽  
High Level ◽  
New Phase ◽  
Design And Construction

The article highlights the participation of the outstanding Russian engineer of railways, designer of locomotives and wagons an extraordinary teacher and the railway administrator, Professor Nikolay Leonidovich Schukin in the design and construction of the imperial train foreign and homeland track. The result of work of the Construction Commission under the leadership of L. Schukin impressed. Effective cooperation leading railwaymen, scientists and engineers of country in the late XIX – early XX centuries has demonstrated a high level of engineering capability in the sector of railway transport and started the beginning of a new phase of homeland locomotive and wagons, little by littlededucing this industry on a par with the railways leading developed countries.

scholarly journals Synthesis, Characterization, and Application of Co-Al-Zn Layered Double Hydroxide/Hydrochar Composite for Simultaneous Removal of Cationic and Anionic Dyes

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Najma Memon ◽  
Urooj Kanwal ◽  
Abdullah Memon ◽  
Safia Sanam Memon ◽  
Saima Qayoom Memon
Keyword(s):  
Layered Double Hydroxide ◽  
Organic Dyes ◽  
Surface Heterogeneity ◽  
General Purpose ◽  
Simultaneous Removal ◽  
Surface Functional Groups ◽  
Anionic Dyes ◽  
Multivariate Technique ◽  
Characterization Studies ◽  
Double Hydroxide

Decontamination of organic dyes from wastewater requires efficient and compatible materials that must be able to remove dyes with different charges at the same time. In this study, composites of layered double hydroxide (LDH) and hydrochar (HC) were prepared and tested for use as general-purpose sorbents for the simultaneous removal of cationic and anionic dyes (i.e., methylene blue (MB), methyl orange (MO), and reactive yellow (RY)). Characterization studies reveal that the surface functional groups on composites are –OH, NO3, M–O bonds. It was observed that crystallinity of LDH decreased with an increasing amount of HC. Preliminary experiments showed that the dyes (i.e., MB, MO, and RY) were well removed simultaneously onto the composite with HC (2.0 g HC/prepared composite). This composite was selected for more experiments, and the adsorption efficiency was optimized by the multivariate technique using the response surface methodology (RSM). Removal efficiency of 100% was obtained for all three dyes with an adsorption capacity of 243, 5.3, and 16.3 µmol g−1 for MB, MO, and RY, respectively. Elovich’s initial intake rates (α) were 4,272, 441, and 99.5 mg g−1 min−1 for RY, MB, and MO, respectively. Data fitted in various models suggested second-order multiplex kinetics, where the surface heterogeneity response was sorbate dependent.

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