scholarly journals Adsorption of Mixed Dye System with Cetyltrimethylammonium Bromide Modified Sepiolite: Characterization, Performance, Kinetics and Thermodynamics

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 981
Author(s):  
Jian Yu ◽  
Aiyi Zou ◽  
Wenting He ◽  
Bin Liu
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Mixed System ◽  
Mixed Solution ◽  
Acid Condition ◽  
Adsorption Sites ◽  
Adsorbent Surface ◽  
Equilibrium Amount ◽  
Adsorption Amount ◽  
Acid Orange Ii ◽  
Positively Charged

In this study, sepiolite was modified by calcination (200 °C) and cetyltrimethylammonium bromide (CTMAB) treatment. Though the specific surface area sharply declined, the adsorption amount of Acid Orange II (AO), Reactive Blue (RB), Acid Fuchsin (AR) and their mixed solution were improved. The morphology of modified sepiolite showed a better dispersibility and looser structure. The adsorption performance was highly impacted by the pH condition and adsorbent dosage. The electrostatic attraction of positively charged adsorption sites on the adsorbent surface and the negatively charged anionic dye could enhance the adsorption amount especially under acid condition. The order of preferentially adsorbed dye was AO > RB > AR. The adsorption process was much correlated to the quasi-second-order reaction kinetics. The adsorption amount and equilibrium amount of single dye system, as well as in the mixed system were in accordance with the Langmuir model and extended Langmuir isotherm.

Sorption Mechanism of Carbon-14 by Hardened Cement Paste

1995 ◽  
Vol 412 ◽  
Author(s):  
K. Noshita ◽  
T. Nishi ◽  
M. Matsuda ◽  
T. Izumida
Keyword(s):  
Electrostatic Force ◽  
Cementitious Materials ◽  
Hardened Cement ◽  
Sorption Mechanism ◽  
Carbon 14 ◽  
Adsorption Sites ◽  
Radioactive Waste Repositories ◽  
Waste Repositories ◽  
Positively Charged

AbstractCarbon-14 sorption by cementitious materials should be enhanced to ensure the long term safety of radioactive waste repositories. The sorption mechanism of inorganic C- 14 (CO32- was investigated using batch sorption experiments and zeta potential measurements. The results suggested that C-14 was adsorbed onto the cement surface by an electrostatic force, due to the reaction between SiO2 and CaO contained in the cementitious composition. That is, SiO2 was originally negatively charged (SiO-) in cement, but became positively charged through the interaction of Ca2+. These positive sites on the SiO2 surface adsorbed inorganic C-14. Ordinary Portland cement (OPC) did not contain enough SiO2 compared with its CaO content to produce sufficient numbers of C-14 adsorption sites. The C-14 distribution coefficient (Kd) was increased from 2,000 to 7,000 mL/g by adding SiO2 to OPC.

A Novel Synthesis of CaWO4:Eu3+ Flower Like Microcrystals in Ethanol/Water Mixed System and Characterization

2012 ◽  
Vol 531-532 ◽  
pp. 512-518 ◽  
Author(s):  
Ye Qing Chen ◽  
Joo Hyun Lee ◽  
Sung Wook Park ◽  
Byung Kee Moon ◽  
Byung Chun Choi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Volume Ratio ◽  
Mixed System ◽  
Mixed Solution ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Xrd Patterns

In this paper, we report a successful synthesis of CaWO4:Eu3+ phosphor via an ethanol assisted hydrothermal process. X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM) were used to investigate the growth of the products. The water and ethanol volume ratio is found to have extraordinary effect on the particle size and morphological appearance. Flower like ~ 1µm superstructures can be obtained with mixed solution of w/e of 50/50 at 120 °C hydrothermal sysnthesis for 12 h. High concentration of ethanol in aqueous solution was discovered to have a tendency in limiting the interaction between the small particles for crystallization. Temperature and time experiments were also performed to further investigate the growth mechanism of the ethanol assisted hydrothermal process. The photoluminescence properties of flower like CaWO4:Eu3+ has also been investigated.

scholarly journals A Comparative Analysis of the Global Electrophilicity Power of Some Cationic Dyes. Understanding Selective Removal Dyes From Mixture Solution

2021 ◽  
Vol 10 (4) ◽  
pp. 2933-2944
Keyword(s):  
Dft Calculations ◽  
Cationic Dyes ◽  
Anionic Sites ◽  
Electrophilicity Index ◽  
Fukui Functions ◽  
Reactive Adsorption ◽  
Adsorption Sites ◽  
Adsorbent Surface ◽  
Dyes Adsorption ◽  
Mixture State

Some bibliographic findings of dyes' adsorption from a mixture state suggest that certain dyes are more likely to be adsorbed first on the adsorbent surface than others, and therefore attracted strongly to the adsorbent surface. To explain the phenomenon, DFT calculations are applied. In this fact, the global electrophilicity index ω of some cationic dyes has been evaluated. The results show that, for studied electrophilic dyes, the molecule with the greatest global electrophilicity power is favored to be adsorbed on the surface's anionic sites. In addition, local electrophilic Parr and Fukui functions were introduced to characterize the most reactive adsorption sites properly and indicate successfully the same adsorption centers. The success of DFT calculations in explaining and predicting the selective dye was assessed.

scholarly journals Synthesis of Multi-organo-functionalized Fibrous silica KCC-1 for Highly Efficient Adsorption of Acid Fuchsine and acid Orange II from Aqueous Solution

2020 ◽  
Author(s):  
Roozbeh Soltani ◽  
Rasool Pelalak ◽  
Mahboubeh Pishnamazi ◽  
Azam Marjani ◽  
Saeed Shirazian
Keyword(s):  
Langmuir Isotherm ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Orange Ii ◽  
Acid Orange ◽  
Adsorption Sites ◽  
Uptake Process ◽  
Acid Orange Ii

Abstract Multi-functionalized fibrous silica KCC-1 (MF-KCC-1) bearing amine, tetrasulfide, and thiol groups was synthesized via a post-functionalization method and fully characterized by several methods such as FTIR, FESEM, EDX-Mapping, TEM, and N2 adsorption-desorption techniques. Due to abundant surface functional groups, accessible active adsorption sites, high surface area (572 m2 g− 1), large pore volume (0.98 cm3 g− 1), and unique fibrous structure, mesoporous MF-KCC-1 was used as a potential adsorbent for the uptake of acid fuchsine (AF) and acid orange II (AO) from water. Different adsorption factors such as pH of the dye solution, the amount of adsorbent, initial dye concentration, and contact time, affecting the uptake process were optimized and isotherm and kinetic studies were conducted to find the possible mechanism involved in the process. for both AF and AO dyes, the Langmuir isotherm model and the PFO kinetic model show the most agreement with the experimental data. The calculated maximum adsorption capacity for AF and AO, according to the Langmuir isotherm, was found to be 574.5 mg g− 1 and 605.9 mg g− 1, respectively, surpassing most adsorption capacities reported until now which is indicative of the high potential of mesoporous MF-KCC-1 as an adsorbent for removal applications.

Specificity of virus adsorption to clay minerals

1985 ◽  
Vol 31 (1) ◽  
pp. 50-53 ◽  
Author(s):  
Steven M. Lipson ◽  
G. Stotzky
Keyword(s):  
Clay Minerals ◽  
Minimal Essential Medium ◽  
Adsorption Sites ◽  
Virus Adsorption ◽  
Serum Amino Acids ◽  
Soils And Sediments ◽  
Reovirus Type ◽  
Fetal Bovine ◽  
Type 3 ◽  
Positively Charged

Competitive adsorption studies indicated that reovirus type 3 and coliphage T1 did not share common adsorption sites on kaolinite and montmorillonite. Compounds in the minimal essential medium (e.g., fetal bovine serum, amino acids) in which the reovirus was maintained blocked adsorption of coliphage T1 to kaolinite and partially to montmorillonite in synthetic estuarine water, but they had no effect on coliphage adsorption to montmorillonite in distilled water or on the adsorption of the reovirus to either clay. The blockage of positively charged sites on kaolinite or montmorillonite by treatment of the clays with sodium metaphosphate or with the supernatants from montmorillonite or kaolinite, respectively, had no effect on adsorption of the reovirus. These data indicate that there was a specificity in adsorption sites for mixed populations of reovirus type 3 and coliphage T1 and emphasize the importance of using more than one type of virus, especially in combination, to predict virus behavior (e.g., adsorption, loss of infectivity) in soils and sediments containing clay minerals.

scholarly journals Synthesis of multi-organo-functionalized fibrous silica KCC-1 for highly efficient adsorption of acid fuchsine and acid orange II from aqueous solution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roozbeh Soltani ◽  
Rasool Pelalak ◽  
Mahboubeh Pishnamazi ◽  
Azam Marjani ◽  
Ahmad B. Albadarin ◽  
...  
Keyword(s):  
Langmuir Isotherm ◽  
High Surface ◽  
High Surface Area ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Orange Ii ◽  
Acid Orange ◽  
Adsorption Sites ◽  
Uptake Process ◽  
Acid Orange Ii

AbstractMulti-functionalized fibrous silica KCC-1 (MF-KCC-1) bearing amine, tetrasulfide, and thiol groups was synthesized via a post-functionalization method and fully characterized by several methods such as FTIR, FESEM, EDX-Mapping, TEM, and N2 adsorption–desorption techniques. Due to abundant surface functional groups, accessible active adsorption sites, high surface area (572 m2 g−1), large pore volume (0.98 cm3 g−1), and unique fibrous structure, mesoporous MF-KCC-1 was used as a potential adsorbent for the uptake of acid fuchsine (AF) and acid orange II (AO) from water. Different adsorption factors such as pH of the dye solution, the amount of adsorbent, initial dye concentration, and contact time, affecting the uptake process were optimized and isotherm and kinetic studies were conducted to find the possible mechanism involved in the process. For both AF and AO dyes, the Langmuir isotherm model and the PFO kinetic model show the most agreement with the experimental data. According to the Langmuir isotherm, the calculated maximum adsorption capacity for AF and AO were found to be 574.5 mg g−1 and 605.9 mg g−1, respectively, surpassing most adsorption capacities reported until now which is indicative of the high potential of mesoporous MF-KCC-1 as an adsorbent for removal applications.

scholarly journals Competitive and Cooperative Adsorption of Aromatic Acids and Bases onto a New Aminated Macroreticular Adsorbent

2005 ◽  
Vol 23 (9) ◽  
pp. 751-762 ◽  
Author(s):  
Wei-Ming Zhang ◽  
Jin-Long Chen ◽  
Bing-Cai Pan ◽  
Quan-Xing Zhang
Keyword(s):  
Single Component ◽  
Aromatic Acids ◽  
Base Interaction ◽  
Adsorption Sites ◽  
Binary Component ◽  
Cooperative Adsorption ◽  
Adsorbent Surface ◽  
Component Systems ◽  
Equilibrium Concentrations ◽  
The Individual

The adsorption behaviour of three aromatic acids [phenol, benzoic acid (BCA) and 2-naphthalene sulphonic acid (2-NSA)] and of one aromatic base (aniline) on an aminated macroreticular adsorbent (NDA103) were investigated employing single or binary batch systems at 293 K and 313 K, respectively. All the adsorption isotherms in the studied systems could be adequately fitted by the Langmuir model, thereby indicating the existence of an exothermic adsorption process for phenol, BCA and aniline. At low equilibrium concentrations, the individual uptakes in the single-component systems were higher than those in binary-component systems because of competition between the two types of adsorbate molecules towards the adsorption sites. On the other hand, it is noteworthy that the total molar uptakes of adsorbates in the binary-component systems at high equilibrium concentrations were larger than the uptakes in the single-component systems. In binary-component systems, a large excess of aromatic acids was noted on the adsorbent surface at saturation, presumably as a result of a cooperative effect arising primarily from acid–base interaction between the loaded adsorbates.

Application of polyether amine, poly alcohol or KCl to maintain the stability of shales containing Na-smectite and Ca-smectite

Clay Minerals ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 29-39
Author(s):  
Shifeng Zhang ◽  
Yanfeng He ◽  
Zhixue Chen ◽  
James J. Sheng ◽  
Lipei Fu
Keyword(s):  
Water Adsorption ◽  
Immersion Test ◽  
Exchangeable Cations ◽  
Mixed Solution ◽  
X Ray Diffraction ◽  
Shale Formations ◽  
X Ray ◽  
Adsorption Sites ◽  
The Stability ◽  
Reduced Water

ABSTRACTThe stability of a shale containing smectite with different exchangeable cations (Na+, Ca2+) was improved using optimum solutions containing polyether amine (PA), poly-alcohol (PO) or KCl. Two types of shale samples with Na+ and Ca2+ as the main exchangeable cations, respectively, were used and the optimized solutions were determined using X-ray diffraction (XRD), an adsorption test, an oedometer swelling test, and an immersion test. The use of KCl prevented intercalation of PA or PO and maintained the stability of the Na-smectite-bearing shale. PA or PO adsorption reduced water adsorption sites on the clay layer, and K+ reduced hydration of exchangeable Na+, resulting in good shale stability in mixed solutions of KCl+PA, and KCl+PO. More stable shale was achieved in KCl+ PA mixed solution, whereas in the KCl+ PO solution the transport of water or solute molecules in the shale was reduced. In the shale containing mainly Ca-smectite, PA, PO and KCl maintained shale stability when applied separately or in common, as PA or PO cannot exchange Ca2+ in the smectite interlayer. As a result, PA or PO should be used together with KCl during drilling in shale formations containing Na-smectite, whereas in shales with Ca-smectite, PA, PO or KCl may be used separately.

scholarly journals Colloidal Stability of Positively Charged Dispersions of Styrene and Acrylic Copolymers in the Presence of TiO2 and CaCO3

2019 ◽  
Vol 3 (1) ◽  
pp. 20 ◽  
Author(s):  
Kamil Wojciechowski ◽  
Małgorzata Gutarowicz ◽  
Kamil Janke ◽  
Ilona Jurek ◽  
Marcin Kaczorowski ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Colloidal Stability ◽  
Antimicrobial Properties ◽  
Ethyl Acrylate ◽  
Ζ Potential ◽  
Bacterial Diseases ◽  
Latex Dispersions ◽  
Acrylic Copolymers ◽  
Alternative Approaches ◽  
Positively Charged

Increasing antibiotic resistance of several pathogenic microorganisms calls for alternative approaches to prevent spreading of bacterial diseases. We propose to employ for this purpose coatings obtained from positively charged latex dispersions. In this contribution we characterize aqueous mixed dispersions containing TiO2 or CaCO3 and methyl methacrylate-ethyl acrylate or styrene-ethyl acrylate copolymers synthesized using a cationic surfactant, cetyltrimethylammonium bromide as an emulsifier. Particle size, electrokinetic (ζ) potential of the mixed dispersions and the resulting thin films, as well as antimicrobial properties of the latter are described. The TiO2 and CaCO3 dispersions were stabilised with polyethyleneimine (PEI) and optimum pH for the mixed dispersions were chosen on the basis of ζ-potential measurements. For TiO2, the maximum ζ = +35 mV was found at pH 7.5, and for CaCO3, pH was set at 8.2 (ζ = +38 mV), to prevent its dissolution. In most 1:1 mixtures of TiO2 or CaCO3 with the cetyltrimethylammonium bromide (CTAB)-stabilised latex dispersions, two distinct particles populations were observed, corresponding to the bare latex and bare TiO2 or CaCO3 fractions. Films made of the mixed dispersions remained positively charged and showed antimicrobial activity similar or reduced with respect to the bare polymer films.

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