scholarly journals Engineering Functionalized Chitosan-Based Sorbent Material: Characterization and Sorption of Toxic Elements

2019 ◽  
Vol 9 (23) ◽  
pp. 5138 ◽  
Author(s):  
Adnan Khan ◽  
Nisar Ali ◽  
Muhammad Bilal ◽  
Sumeet Malik ◽  
Syed Badshah ◽  
...  
Keyword(s):  
Experimental Data ◽  
Sorption Isotherms ◽  
Analytical Techniques ◽  
Aqueous Environment ◽  
X Ray Diffraction ◽  
Sorption Data ◽  
Regression Methods ◽  
Sorbent Material ◽  
Lead And Cadmium ◽  
Cadmium And Lead

The present study reports the engineering of functionalized chitosan (CH)-based biosorbent material. Herein, a two-step reaction was performed to chemically modify the CH using 1,4-bis(3-aminopropyl) piperazine to incorporate nitrogen basic centers for cations sorption from the aqueous environment. The resultant functionalized chitosan-based sorbent material was designated as CH-ANP and characterized using various analytical techniques, including elemental analysis, Fourier-transform infrared spectroscopy (FTIR), 13C NMR (in solid-state), X-ray diffraction, and thermal analysis. Then, the newly engineered CH-ANP was employed for the removal of copper, lead, and cadmium in the aqueous medium. Langmuir sorption isotherm analysis revealed that the highest sorption abilities achieved were 2.82, 1.96, and 1.60 mmol g−1 for copper, cadmium, and lead, respectively. Linear and nonlinear regression methods were deployed on the sorption data to study the behavior of the Langmuir, the Freundlich, and the Temkin sorption isotherms. Among the four different forms, the Langmuir isotherm type 1 fit well to the experimental data as compared to the other models. It also showed the lowest values of error, and a higher correlation coefficient than the Freundlich and Temkin models; thus it was the best fit with the experimental data compared to the latter two models. In conclusion, the findings suggest that chemically modified novel materials with enhanced Lewis basic centers are useful and promising candidates for the sorption of various toxic cations in aqueous solution.

scholarly journals Studies of Dye Sensitisation Kinetics and Sorption Isotherms of Direct Red 23 on Titania

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Peter J. Holliman ◽  
Beatriz Vaca Velasco ◽  
Ian Butler ◽  
Maarten Wijdekop ◽  
David A. Worsley
Keyword(s):  
Sorption Isotherms ◽  
Freundlich Isotherm ◽  
Zero Point ◽  
Sorption Kinetics ◽  
X Ray Diffraction ◽  
Dye Sensitization ◽  
Sorption Data ◽  
Charge Analysis ◽  
Uptake Data ◽  
Kinetics And Isotherms

Sorption kinetics and isotherms have been measured for a commercial dye (Direct Red 23) on different samples of powdered Titania, and the data were analysed to better understand the dye sensitization process for dye sensitised solar cells (DSSCs). For the sorption kinetics, the data show rapid initial sorption (<1 hour) followed by slower rate of increasing uptake between 1 and 24 hours. While higher initial concentrations of dye correspond to higher sorption overall, less dye is absorbed from higher initial dye concentrations when considered as percentage uptake. The correlation between the sorption data and model isotherms has been considered with time. The Langmuir model shows better correlations compared to the Freundlich isotherm. The dye uptake data has also been correlated with Titania characterization data (X-ray diffraction, scanning electron microscopy, BET and zero point charge analysis). Kinetic data show significantly better fits to second-order models compared to first order. This suggests that chemisorption is taking place and that the interaction between the dye sorbate and the Titania sorbent involves electron sharing to form an ester bond.

Moisture Sorption Isotherms, Isosteric Heat of Sorption and Glass Transition Temperature of Murtilla (Ugni molinae T.) Berry

2014 ◽  
Vol 10 (4) ◽  
pp. 583-594 ◽  
Author(s):  
Kong S. Ah-Hen ◽  
Roberto Lemus-Mondaca ◽  
Karen A. Mathias-Rettig ◽  
Antonio Vega-Gálvez ◽  
Jessica López
Keyword(s):  
Experimental Data ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Moisture Content ◽  
Sorption Isotherms ◽  
Isosteric Heat ◽  
Sorption Data ◽  
Heat Of Sorption ◽  
Ugni Molinae

Abstract Adsorption and desorption isotherms of fresh and dried murtilla (Ugni molinae Turcz) berries were determined at 20, 40 and 60°C using a gravimetric technique. The experimental data obtained were fitted to eight models, namely GAB, BET, Henderson, Caurie, Smith, Oswin, Halsey and Iglesias–Chirife. A non-linear least square regression analysis was used to evaluate the models. The GAB model best fitted the experimental data. Isosteric heat of sorption was determined from the equilibrium sorption data using the Clausius–Clapeyron equation and was found to decrease exponentially with increasing moisture content. The enthalpy–entropy compensation theory applied to the sorption isotherms indicated an enthalpy controlled sorption process. Glass transition temperature of murtilla was determined by differential scanning calorimetry and modelled as a function of moisture content by the Gordon–Taylor equation and as function of water activity by Roos and Khalloufi models, which proved to be excellent tools for predicting glass transition of murtilla.

scholarly journals Anchoring of CoHFC nanoparticles on clinoptilolite for remedy of nuclear wastes

2017 ◽  
Vol 32 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Taher Yousefi ◽  
Hamid Mahmudian ◽  
Meisam Torab-Mostaedi ◽  
Mohammad Moosavian ◽  
Reza Davarkhah
Keyword(s):  
Experimental Data ◽  
X Ray Diffraction ◽  
Sorption Data ◽  
Modified Zeolite ◽  
First Order ◽  
Batch System ◽  
Adsorption Capacities ◽  
Double Exponential ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

To improve the mechanical properties, the cobalt ferrocyanide precipitation was carried out on clinoptilolite as an inorganic polymer. In this work the combination of two important factors, stability (zeolite) and high adsorption capacity (cobalt ferrocyanide) were considered to improve the ions uptake ability of adsorbent. The modification was approved by X-ray diffraction, Scanning electronic microscopy and Fourier transform infrared spectroscopy. The modified zeolite was applied to remove Sr(II) and Cs(I) ions from aqueous solution in a batch system. The adsorption capacities of modified zeolite for Cs(I) and Sr(II) improved to 90 and 130 mgg-1, respectively. The Sr(II) and Cs(I) removal were investigated as a function of shaking time, pH, Sr(II), and Cs(I) initial concentration and temperature. The experimental data were fitted well to Langmuir isotherm model for two sorbet metal ions. The time dependence sorption data showed that the uptakes of Cs(I) and Sr(II) were very rapid and apparent sorption equilibriums were achieved within 100 min of contact time. The kinetic experimental data were fitted to the pseudo-first order, pseudo-second order, the double exponential, Elovich and intraparticle diffusion models. The sorption rates and capacities as well as rate constants were evaluated.

scholarly journals Immobilization of heavy Pb(II) and Cd(II) ions from aqueous discharges

2021 ◽  
Vol 4 (3) ◽  
pp. 96-105
Author(s):  
Said Al Rabadi
Keyword(s):  
Experimental Data ◽  
Metal Ions ◽  
Analytical Techniques ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Wastewater Purification ◽  
And Behavior ◽  
In Virtue Of

Jordanian sand deposits are naturally available in enormous amounts, located in Sweileh area, West Amman, which are mainly composed of low costs constituents from silica, Kaolin Clay, and metal oxides. A novel and simple methodology is presented for preparation, characterization, and behavior assessment of the potential nano-Kaolinite/ Silica oxides composites (nKSOC), for the immobilization of heavy Pb(II) and Cd(II) ions from aqueous solutions’ discharges. In this study, the synthesis of nKSOC composites was conducted from the Jordanian sand deposits, mechanically reduced in size and then chemically acid-activated at room temperature, for the scope of wastewater purification through adsorption of heavy Pb(II) and Cd(II) ions from an aqueous medium. The synthesized nKSOC were subjected to analytical techniques; X-ray diffraction (XRD) and size reduction, to deduce their appropriate characterizations. Key parameters, considered for the enhancement of the adsorption technique, were pH, initial metal ions concentration, contact time, sorbent's dosage, and temperature. Experimental data were analyzed by Langmuir and Freundlich isotherm models, for the prediction of the adsorption behavior. Langmuir isotherms reproduce the experimental data with a maximum adsorption capacity of 172.4 (mg/gadsorbent) and 158.7 (mg/gadsorbent) for Pb(II) and Cd(II) ions, respectively, under unchangeable conditions of the constant temperature of 303K and slightly acidic pH in the range of 5.5 - 6. The adsorption of heavy metal ions was spontaneous and endothermic; (∆Ho) (7.47 kJ/mol) and 7.87 (kJ/mol) for Pb(II) and Cd(II) ions, respectively, and with negative Gibbs free energy (∆Go), the adsorption process is performed under mild conditions. In virtue of these remarkable findings, nKSOC could be effectively used as a low-prized adsorbent to uptake heavy Pb(II) and Cd (II) metals from aqueous waste media.

Modeling of moisture sorption isotherm and evaluation of net isosteric heat for spray-dried fortified coconut (Cocos nucifera L.) powder

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juan Carlos Lucas Aguirre ◽  
German Antonio Giraldo Giraldo ◽  
Misael Cortés Rodríguez
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Isosteric Heat ◽  
Fundamental Parameter ◽  
Sorption Data ◽  
Content Type ◽  
Moisture Sorption Isotherms ◽  
Different Temperatures

PurposeIn order to understand interactions aw vs equilibrium moisture content (EMC) in fortified coconut powder, moisture sorption isotherms were constructed under different storage conditions in order to predict the changes in their physical, chemical and microbiological properties that occur during storage and processing, which are unique to each food.Design/methodology/approachFor which the moisture sorption isotherms were determined at three different temperatures (15, 25 and 35 °C), in a range of water activity from 0.1 to 0.90. Nine models, namely, the GAB, BET, Oswin, Smith, Halsey, Henderson, Chung and Pfost, Peleg and Caurie equations, were fitted to the sorption data. Various statistical tests were adopted as criteria to evaluate the fit performance of the models.FindingsOf the models tested, the Peleg model gave the best fit to experimental data (R2 = 0.997; RMSE = 0.276), across the full range of water activities and at different temperatures. Humidity of the monolayer (mo) was found between 2.54 and 2.34%, a fundamental parameter to define the storage and control conditions, given that it is considered the value at which the product is more stable. The net sorption isosteric heat (Qst) increased to maximum and then diminished with increased moisture content (Xw); maximum values were obtained in the Xw interval between 0.48 and 2.87% (db), being between 35.72 and 99.26 kJ/mol, where the maximum value indicates coverage of the strongest bond sites and higher adsorbate-adsorbent interaction.Originality/valueThese results provide reliable experimental data on water absorption isotherms of the CP + FAC important to determine optimal processing, storing and packaging conditions.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

scholarly journals Zeolite NaP1 Functionalization for the Sorption of Metal Complexes with Biodegradable N-(1,2-dicarboxyethyl)-D,L-aspartic Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus
Keyword(s):  
Experimental Data ◽  
Aspartic Acid ◽  
Ph Value ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Modified Zeolite ◽  
X Ray ◽  
Slow Release Fertilizers ◽  
Pseudo Second Order

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.

scholarly journals Analytical study of Buddha sculptures in Jingyin temple of Taiyuan, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

AbstractWith exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

scholarly journals Novel Preparation of Noncovalent Modified GO Using RAFT Polymerization to Reinforce the Performance of Waterborne Epoxy Coatings

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 348 ◽  
Author(s):  
Baolei Liu ◽  
Mingqian Wang ◽  
Ying Liang ◽  
Zhicheng Zhang ◽  
Guohong Ren ◽  
...  
Keyword(s):  
Raft Polymerization ◽  
Salt Spray ◽  
Thermo Gravimetric Analysis ◽  
Analytical Techniques ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Block Polymer ◽  
Reversible Addition ◽  
Waterborne Epoxy ◽  
And Performance

This work launches the first-ever report on the fabrication of waterborne epoxy-graphene oxide (GO) coatings (WEGC) using a block polymer as a dispersant of GO, wherein the block polymer was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid and oligo(ethylene glycol) methyl ether methacrylate A number of analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and salt spray tests, were utilized to explore the morphology and performance of the WEGC. It was confirmed that POEGMA950-b-PAA attached to the GO nanosheets, increasing the integral space of the sheets. Modified GO (MGO) layers were well-dispersed in the epoxy matrix through the formation of a GO-dispersant-epoxy ternary molecular structure. Furthermore, the presence of MGO substantially influenced the thermal properties, mechanical properties, and anticorrosion performance of the WEGC. TGA, salt spray tests, and pull-off testsshowed that 0.5 wt.% MGO content achieved the greatest improvement in the evaluated properties.

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