Preparation of Al2O3 Whiskers from AACH Using Hydrothermal Method and its Use for the Removal of Lead Ions by Adsorption

This work explores the potential of adsorption of Pb2+ by hydrothermally synthesized alumina. In comparison to other heavy ion removal techniques, adsorption is preferred in the current study as it has the edge of ease of operation and environment friendly characteristics. Synthesis of high surface area alumina whiskers was achieved by hydrothermal route which were subsequently employed for the active adsorption of lead ions. AACH (Ammonium Aluminum Carbonate Hydroxide), used as precursor for alumina, was calcined at three different temperatures i.e. 700, 900 and 1100 °C to form alumina whiskers. These whiskers were characterized by XRD, SEM, BET and FTIR. Various adsorption parameters such as contact time, pH, initial metal concentration were studied for lead ions. Maximal removal efficiency was obtained for the specimen having pH 4 and calcined at 700 °C for 60 minutes. Kinetic data was best described by pseudo second order model, whereas the adsorption equilibrium data obeyed the Langmuir adsorption isotherm model.

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Effective Poly (Cyclotriphosphazene-Co-4,4′-Sulfonyldiphenol)@rGO Sheets for Tetracycline Adsorption: Fabrication, Characterization, Adsorption Kinetics and Thermodynamics

Nanomaterials ◽

10.3390/nano11061540 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1540

Author(s):

Muhammad Ahmad ◽

Tehseen Nawaz ◽

Mohammad Mujahid Alam ◽

Yasir Abbas ◽

Shafqat Ali ◽

...

Keyword(s):

Adsorption Capacity ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

High Adsorption ◽

Clean Environment ◽

Equilibrium Data ◽

Langmuir Isotherm Model ◽

High Adsorption Capacity ◽

Adsorption Equilibrium Data

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.

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Effect of the Pore Diameters and Amino-Organo Functional Structures on Mesoporous Silicas for DNA Adsorption

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.720.31 ◽

2016 ◽

Vol 720 ◽

pp. 31-36 ◽

Cited By ~ 2

Author(s):

Ryouichi Hikosaka ◽

Fukue Nagata ◽

Masahiro Tomita ◽

Katsuya Kato

Keyword(s):

Pore Size ◽

Functional Groups ◽

High Surface ◽

High Surface Area ◽

Freundlich Isotherm ◽

Isotherm Models ◽

Surface Functional Groups ◽

Dna Adsorption ◽

Equilibrium Data ◽

Adsorption Equilibrium Data

Deoxyribonucleic acid (DNA) adsorption onto particles has applications in biosensors, separation methods, and gene delivery. Mesoporous silica (MPS), which exhibits a high surface area and large pore volume, is used in these applications because its pore size is easily controlled and its surface functional groups are easily exchanged. In this study, three types of MPSs with different pore sizes (2.4, 5.6, and 11.8 nm) were functionalized with different aminosilane coupling reagents and the effects of the MPS pore size and surface functional groups on DNA adsorption were evaluated. As the pore size of MPS increased, MPSs with diethylenetriamine (–3NH2) adsorbed higher amounts of DNA, whereas MPSs with hexylenediamine groups (–2HNH2) adsorbed lower amounts of DNA. Moreover, the fitting of DNA adsorption equilibrium data to Langmuir and Freundlich isotherm models was investigated.

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Enhanced removal of Cr(III), Mn(II), Cd(II), Pb(II) and Cu(II) from aqueous solution by N-functionalized ordered silica

10.21203/rs.3.rs-196968/v1 ◽

2021 ◽

Author(s):

Natalia Kobylinska ◽

Vadim Kessler ◽

Gulaim Seisenbaeva ◽

Oksana Dudarko

Keyword(s):

Mesoporous Silica ◽

Metal Ions ◽

Metal Removal ◽

High Surface ◽

High Surface Area ◽

Tem Analysis ◽

Adsorption Capacities ◽

Removal Of Heavy Metals ◽

Equilibrium Data ◽

Adsorption Equilibrium Data

Abstract Chelating and ion-exchange N-functionalized mesoporous silicas (SBA-15) as selective adsorbents for removal of heavy metals were synthesized using template method. Fourier transform infrared spectroscopy, TEM analysis, N2 adsorption/desorption isotherms and titration analysis conﬁrmed successful functionalisation of the tri-sodium salt of N-(triethoxysilylpropyl)ethylenediaminetriacetic acid (EDTA), protonated primary amine (NH3+Cl-) and its combinations onto the mesoporous silica (SBA-EDTA/NH2). The obtained materials featured beneﬁcial properties of mesoporous silica SBA-15 with its high surface area and were successfully fictionalized with N-containing groups. The synthesized series of silicas were investigated for removal of Cr(III), Mn(III), Pb(II), Cd(II) and Cu(II) from model water solutions. The adsorption of target ions increased with the increase pH and its concentration in solution. The adsorption equilibrium data were well ﬁtted to Langmuir isotherm model and maximum monolayer adsorption capacities for cations Pb(II), Cd(II), Cr(III) and Mn(II) were 185.6 mg g-1, 111.2 mg g-1, 57.7 mg g-1 and 49.4 mg g-1, respectively. The chelating interaction was considered as the main adsorption mechanism for metal ions (Cr(III), Mn(II), Pb(II), Cd(II), and Cu(II)). The adsorption capacities of SBA-EDTA and SBA-EDTA/NH2 samples toward studied metal ions were consistent with the Lewis ‘hard and soft acids and bases’ theory. The metal removal efficiency of adsorbents was near 96-92 % during three regeneration cycles. All these results indicated that the produced N-functionalized silica were promising for applications in environmental and analytical separation ﬁelds.

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Experimental and Modeling of Dicamba Adsorption in Aqueous Medium Using MIL-101(Cr) Metal-Organic Framework

Processes ◽

10.3390/pr9030419 ◽

2021 ◽

Vol 9 (3) ◽

pp. 419

Author(s):

Hamza Ahmad Isiyaka ◽

Khairulazhar Jumbri ◽

Nonni Soraya Sambudi ◽

Jun Wei Lim ◽

Bahruddin Saad ◽

...

Keyword(s):

Aqueous Medium ◽

Adsorption Capacity ◽

Environmental Concern ◽

Metal Organic Framework ◽

High Surface ◽

High Surface Area ◽

Data Matrix ◽

Adsorption Parameters ◽

Metal Organic ◽

Organic Framework

Drift deposition of emerging and carcinogenic contaminant dicamba (3,6-dichloro-2-methoxy benzoic acid) has become a major health and environmental concern. Effective removal of dicamba in aqueous medium becomes imperative. This study investigates the adsorption of a promising adsorbent, MIL-101(Cr) metal-organic framework (MOF), for the removal of dicamba in aqueous solution. The adsorbent was hydrothermally synthesized and characterized using N2 adsorption-desorption isotherms, Brunauer, Emmett and Teller (BET), powdered X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR) and field emission scanning electron microscopy (FESEM). Adsorption models such as kinetics, isotherms and thermodynamics were studied to understand details of the adsorption process. The significance and optimization of the data matrix, as well as the multivariate interaction of the adsorption parameters, were determined using response surface methodology (RSM). RSM and artificial neural network (ANN) were used to predict the adsorption capacity. In each of the experimental adsorption conditions used, the ANN gave a better prediction with minimal error than the RSM model. The MIL-101(Cr) adsorbent was recycled six times to determine the possibility of reuse. The results show that MIL-101(Cr) is a very promising adsorbent, in particular due to the high surface area (1439 m2 g−1), rapid equilibration (~25 min), high adsorption capacity (237.384 mg g−1) and high removal efficiency of 99.432%.

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Modified Dual-Site Langmuir Adsorption Equilibrium Models from A GCMC Molecular Simulation

Applied Sciences ◽

10.3390/app10041311 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1311

Author(s):

Junchao Wang ◽

Yongjie Wei ◽

Zhengfei Ma

Keyword(s):

Molecular Simulation ◽

Adsorption Energy ◽

Pressure Swing Adsorption ◽

Adsorption Equilibrium ◽

Equilibrium Data ◽

Different Temperatures ◽

Adsorption Energies ◽

Pressure Swing ◽

Adsorption Equilibrium Data ◽

Dual Site

In the modern industrial separation process, the pressure swing adsorption technology is widely used to separate and purify gases due to its low energy consumption, low cost, convenience, reliability, and environmental benignity. The basic elements of the design and application of the pressure swing adsorption process are adsorption isotherms at different temperatures for adsorbents. The dual-site Langmuir (DSL) adsorption equilibrium model is the mostly used model; however, this model is based on the assumption that the adsorption energy on the surface of an adsorbent is uniform and remains unchanged. Here, a grand canonical Monte Carlo (GCMC) molecular simulation was used to calculate the CO2 adsorption equilibrium on MIL-101 (Cr) at 298 K. MIL-101 (Cr) was chosen, as it has more a general pore structure with three different pores. The calculation results showed that the adsorption energies with different adsorption pressures fitted a normal distribution and the relationship of the average adsorption energies, E with pressures had a linear form described as: E = aP + c. With this relationship, the parameter b = k·exp(E/RT) in the DSL model was modified to b = k·exp((aP + c)/RT), and the modified DSL model (M-DSL) was used to correlate the adsorption equilibrium data on CO2-MIL-101 (Cr), C2H4-HHPAC, CH4-BPL, and CO2-H-Mordenite, showing better correlations than those of the DSL model. We also extended the parameter qm in the M-DSL model with the equation qm = k1 + k2T to adsorption equilibrium data for different temperatures. The obtained model (M-TDSL) was checked with the abovementioned adsorption equilibrium systems. The fitting results also indicated that the M-TDSL model could be used to improve the correlation of adsorption equilibrium data for different temperatures. The linear relationship between the average adsorption energy and adsorption pressure could be further tested in other adsorption equilibrium models to determine its universality.

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Investigation on adsorption capacity of TiO2-P25 nanoparticles in the removal of a mono-azo dye from aqueous solution: A comprehensive isotherm analysis

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq120610105b ◽

2014 ◽

Vol 20 (1) ◽

pp. 97-107 ◽

Cited By ~ 26

Author(s):

Mohammad Behnajady ◽

Shahrzad Yavari ◽

Nasser Modirshahla

Keyword(s):

Aqueous Solution ◽

Crystallite Size ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

Correlation Coefficients ◽

Average Crystallite Size ◽

Isotherm Models ◽

Equilibrium Data ◽

Pseudo Second Order

In this work TiO2-P25 nanoparticles with high surface area have been used as adsorbent for the removal of C.I Acid Red 27 (AR27), as an organic contaminant from aqueous solution. Characteristics of phases and crystallite size of TiO2-P25 nanoparticles were achieved from XRD and the surface area and pore size distribution were obtained from BET and BJH techniques. TiO2-P25 nanoparticles with almost 80% anatase and 20% rutile phases, the average crystallite size of 18 nm, have specific surface area of 56.82 m2 g-1. The effect of various parameters like initial AR27 concentration, pH, contact time and adsorbent dosage has been carried out in order to find desired adsorption conditions. The desired pH for adsorption of AR27 onto TiO2-P25 nanoparticles was 3. The equilibrium data were analyzed with various 2-, 3- and 4-parameter isotherm models. Equilibrium data fitted very well by the 4-parameter Fritz-Schluender model. Results of adsorption kinetics study indicated that the pseudo-second order kinetics provided the best fit with correlation coefficients close to unity.

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MICROWAVE ASSISTED K2CO3 PALM SHELL ACTIVATED CARBON AS SORBENT FOR CO2 ADSORPTION APPLICATION

Jurnal Teknologi ◽

10.11113/jt.v78.9576 ◽

2016 ◽

Vol 78 (8-3) ◽

Author(s):

Usman Dadum Hamza ◽

Noor Shawal Nasri ◽

Nor Aishah Saidina Amin ◽

Jibril Mohammed ◽

Husna Mohd Zain

Keyword(s):

Activated Carbon ◽

Porous Carbon ◽

Co2 Adsorption ◽

Co2 Uptake ◽

Adsorption Method ◽

Equilibrium Data ◽

Different Temperatures ◽

Co2 Adsorption Capacity ◽

Adsorption Equilibrium Data ◽

Best Fit

Carbon dioxide is believed to be a major greenhouse gas (GHG) that contributes to global warming. In this study, palm shells were used as a precursor to prepare CO2 activated carbon sorbents via carbonization, chemical impregnation with K2CO3 and microwave activation. Adsorption equilibrium data for CO2 adsorption on the porous carbon were obtained at different temperatures using static volumetric adsorption method. Langmuir, Freundlich, Sips and Toths models were used to correlate the experimental data. The CO2 adsorption capacity at 303.15, 343.15, 378.15 443.15 K and 1 bar on the sorbent was 2.71, 1.5, 0.77, 0.69 mmol/g respectively. Sips isotherm was found to have the best fit. The results indicated that the porous carbon sorbent prepared by carbonization and microwave K2CO3 assisted activation have good CO2 uptake. The porous carbons produced are therefore good candidates for CO2 adsorption applications

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Facile Fabrication of Single Crystalline Ceria Nanoparticles for Photo-Responsive Applications

Materials Science Forum ◽

10.4028/www.scientific.net/msf.734.127 ◽

2012 ◽

Vol 734 ◽

pp. 127-137

Author(s):

D.P. Das ◽

Armita Dash ◽

B.K. Mishra

Keyword(s):

Surface Area ◽

High Surface ◽

High Surface Area ◽

Band Gap Energy ◽

Ceria Nanoparticles ◽

Processing Conditions ◽

Hydrothermal Route ◽

Single Crystalline ◽

Nanocrystallite Size ◽

Facile Fabrication

The present investigation is about fabrication of single-crystalline ceria (CeO2) nanoparticle by a hydrothermal route. High surface area CeO2 was synthesized with transformation of morphology from nanofibers to nanocubes in response to processing conditions. A steady variation of average nanocrystallite size ca. in the range 3.0-16.9 nm and a range of band gap energy from 2.6 to 2.9 eV were measured. The surface area of the nanoparticles varied in the range 16.0136.1 m2/g and the variation in surface area is attributed to the nature of packing of particles. The ceria nanofibers could generate 870.5 µmol of H2 in 3 h of irradiation.

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Methanation of CO2 over Cobalt-Lanthanide Aerogels: Effect of Calcination Temperature

Catalysts ◽

10.3390/catal10060704 ◽

2020 ◽

Vol 10 (6) ◽

pp. 704 ◽

Cited By ~ 2

Author(s):

Joaquim Badalo Branco ◽

Ricardo Pinto da Silva ◽

Ana Cristina Ferreira

Keyword(s):

High Surface ◽

High Surface Area ◽

Oxide Phase ◽

Addition Method ◽

Acid Base ◽

Lanthanide Oxide ◽

Lanthanide Series ◽

Rh Catalyst ◽

Different Temperatures ◽

First Time

High surface area cobalt-lanthanide bimetallic aerogels were successfully synthesized by the epoxide addition method. The bimetallic aerogels were calcined at two different temperatures and either bimetallic oxides containing oxychlorides, Co3O4.3LnOCl (Ln = La, Sm, Gd, Dy and Yb) or perovskites, LnCoO3 (Ln = La, Sm, Gd and Dy) were obtained at 500 or 900 °C, respectively. The exceptions are the aerogels of cerium and ytterbium, which after oxidation at 500 and 900 °C, stabilize as sesquioxides: Co3O4.3CeO2 and 2Co3O4.3Yb2O3, the first at both temperatures and the second only at the highest temperature. The bimetallic cobalt-lanthanide oxychlorides or perovskites were tested as catalysts for the methanation of CO2. The cobalt catalytic activity is determined by the type and acid-base properties of the lanthanide oxide phase and by its pre-reduction under hydrogen. The best results were those obtained over the calcined aerogels pre-reduced under hydrogen. In particular, the highest values were those obtained over the Co-Ce aerogel calcined at 900 °C that in the same conditions present an activity comparable to that measured over a 5 wt.% Rh catalyst supported on alumina, one of the literature references. The activity and the selectivity increase with the catalysts’ basicity, showing an inverse dependence of the reduction temperature that decreases along the lanthanide series either for the aerogels calcined at 500 or 900 °C. In general, the basicity of the aerogels calcined at 900 °C (perovskites) is higher and they are more active but less selective than those calcined at 500 °C (oxychlorides), which to our knowledge is for the first time reported for the methanation of CO2.

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