Biopolymer Encapsulation of PEI-Derivatives for Heavy Metal Sorption

2015 ◽  
Vol 1130 ◽  
pp. 529-532
Author(s):  
Caroline Bertagnolli ◽  
Thierry Vincent ◽  
Eric Guibal
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Metal Sorption ◽  
Initial Concentration ◽  
Heavy Metal Sorption ◽  
Maximum Sorption ◽  
Complex Solutions ◽  
Scanning Electron

Composite materials have been synthesized by alginate or chitosan encapsulation of polyethylenimine (PEI) derivatives (obtained by glutaraldehyde grafting of histidine and carbon disulfide). Discrete or agglomerated PEI-derivative particles are immobilized in the macroporous network of biopolymer matrix (as shown by scanning electron microscopy and SEM-EDX analysis). The effect of pH and initial concentration on Zn (II) and Cu (II) sorption performance were analyzed. The incorporation of PEI-derivatives biopolymer matrix improves sorption performance in complex solutions (doped with CaCl2) compared to pristine biopolymer. Maximum sorption capacities range from 0.64 to 1 mmol L-1 for Zn (II) and from 1.13 to 1.67 mmol L-1 for Cu (II).

Influence of Sodium Hydroxide on the Properties of FGD Gypsum-Slag Composite Materials

2014 ◽  
Vol 675-677 ◽  
pp. 750-755
Author(s):  
Fang Huang ◽  
Bao Long Jiao ◽  
Dong Dong Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Flexural Strength ◽  
Sodium Hydroxide ◽  
Setting Time ◽  
Maximal Strength ◽  
Action Mechanism ◽  
Fgd Gypsum ◽  
Scanning Electron

By examining the compressive and flexural strength of composite and using scanning electron microscopy (SEM), we analyzed the influence of sodium hydroxide on the properties of FGD gypsum and slag composite materials and discussed the influence of sodium hydroxide on the setting time and mechanical strength of the composite materials and presented the action mechanism of sodium hydroxide as a stimulator. The results show that when the content of sodium hydroxide was percent of 0.25, the maximal strength of FGD gypsum-slag composite materials was reached.

Processability of Composite Materials Containing Chitosan

1990 ◽  
Vol 218 ◽  
Author(s):  
G. Graham Allan ◽  
Mutombo Muvundamina
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Electron Spectroscopy ◽  
Surface Composition ◽  
Polypropylene Fibers ◽  
Acidic Solutions ◽  
Foreign Materials ◽  
Wetting Force ◽  
Scanning Electron

AbstractThe processability of polypropylene fibers into composite materials was characterized by dynamic wettability measurements. Single fibers were immersed in a series of aqueous acidic solutions of chitosan. Variations in the wetting force, observed for progressive and successive immersions of the fibers in the liquid, indicated adsorption of species out of the solution or the presence of foreign materials on the surface of the solid. The value of the advancing wetting force was used to assess the coating of the fibers by the liquid. Data on the surface composition of the fibers were obtained by electron spectroscopy for chemical analysis. The conditions of preparation of the composite materials containing chitosan were determined from the correlation of the observations on wettability, surface composition and scanning electron microscopy.

scholarly journals Production of Nanocrystalline Magnetite for Adsorption of Cr(VI) Ions

2012 ◽  
Vol 05 ◽  
pp. 771-783
Author(s):  
N. JAVADI ◽  
SH. RAYGAN ◽  
S. A. SEYYED EBRAHIMI
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Standards ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
X Ray ◽  
Adsorption Data ◽  
Atomic Adsorption Spectroscopy ◽  
Langmuir Isotherm Model ◽  
Scanning Electron

Higher environmental standards have made the removal of toxic metals such as hexavalent chromium from wastewater; an important problem for environmental protection. Iron oxide is a particularly interesting adsorbent to be considered for this application. In this study, a new method combining adsorption and magnetic separation was developed to remove Cr ( VI ) from wastewater. The nanocrystalline magnetite as adsorbent was produced via thermo- mechanical reduction of hematite. Various parameters which affect the adsorption of Cr ( VI ) such as time, pH, temperature and initial concentration were investigated using thermo-gravimeters (TG), X-Ray diffraction (XRD), scanning electron microscopy (SEM) and atomic adsorption spectroscopy (AAS) techniques. The maximum adsorption was occurred at pH 2. The adsorption data were fitted well to Langmuir isotherm model. The adsorption of Cr ( VI ) increased significantly with increasing of temperature and time.

Study on the adsorption of bacteria in ceramsite and their synergetic effect on adsorption of heavy metals

2013 ◽  
Vol 69 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Shan Qiu ◽  
Fang Ma ◽  
Xu Huang ◽  
Shanwen Xu
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Adsorption Capacity ◽  
Synergetic Effect ◽  
Covalent Bond ◽  
Metal Adsorption ◽  
Heavy Metal Adsorption ◽  
Scanning Electron

In this paper, heavy metal adsorption by ceramsite with or without Bacillus subtilis (B. subtilis) immobilization was studied, and the synergetic effect of ceramsite and bacteria was discussed in detail. To investigate the roles of the micro-pore structure of ceramsite and bacteria in removing heavy metals, the amount of bacteria immobilized on the ceramsite was determined and the effect of pH was evaluated. It was found that the immobilization of B. subtilis on the ceramsite was attributed to the electrostatic attraction and covalent bond. The scanning electron microscopy results revealed that, with the presence of ceramsite, there was the conglutination of B. subtilis cells due to the cell outer membrane dissolving. In addition, the B. subtilis immobilized ceramsite showed a different adsorption capacity for different heavy metals, with the adsorption capacity ranking of La3+ > Cu2+ > Mg2+ > Na+.

scholarly journals Tribological Properties of Al-Based Composites Reinforced with Fullerene Soot

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6438
Author(s):  
Firuz Yunusov ◽  
Tatiana V. Larionova ◽  
Oleg Tolochko ◽  
Alexander D. Breki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Pure Aluminum ◽  
Fullerene Soot ◽  
Scanning Electron

Aluminum-based composite materials reinforced with fullerene soot, which is a mixture of fullerene and amorphous carbon, are promising materials for friction and wear applications. Composite materials: aluminum with 2% fullerene soot (f.s) and Al with 2% f.s and 2% Cu were obtained via mechanical milling followed by hot pressing. The tribological properties (friction and wear) of the listed composites were investigated and compared with the results for pure aluminum obtained under similar conditions. It has been shown that the addition of fullerene soot reduces the friction coefficient by 25%. At additional alloying with copper, the friction coefficient decreased by 35% in comparison with pure aluminum and also lad to a decrease in friction fluctuations. The wear rate of composite Al with 2% f.s decreased twice in comparison with that of pure aluminum, and with additional alloying it decreased 2.5 times. The morphology of the wear surfaces was investigated by scanning electron microscopy (SEM). The influence of fullerene soot and additional alloying on the wear mechanism was shown.

scholarly journals Synthesis and Heavy-Metal Sorption Studies of N,N-Dimethylacrylamide-Based Hydrogels

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3084
Author(s):  
Ayatzhan Akhmetzhan ◽  
Nurgeldi Abeu ◽  
Sotirios Nik. Longinos ◽  
Ayezkhan Tashenov ◽  
Nurbala Myrzakhmetova ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
Radical Polymerization ◽  
Ammonium Persulfate ◽  
Adsorption Behavior ◽  
Metal Sorption ◽  
Initial Concentration ◽  
Swelling Degree ◽  
Heavy Metal Sorption ◽  
Hydrogel System

In this work, a hydrogel system was produced via radical polymerization of N,N-dimethylacrylamide and 2-acrylamido-2-methylpropanesulfonic acid in the presence of N,N-methylene-bis-acrylamide as a crosslinker and ammonium persulfate as an initiator. Parameters that impact the conversion of copolymerization (such as initial concentration of monomers, temperature, initiator dose, and time) were studied. The swelling degree of the hydrogel was investigated with the addition of a crosslinker and initiator at different pH levels. A hydrogel with high conversion and high swelling degree was selected to investigate their ability for adsorption of Pb(II) ions from solutions. Adsorption behavior of Pb(II) ions in a hydrogel was examined as a function of reaction time and concentration of lead ions from a solution of Pb(II) ions.

Validation of the expert methodology «Detection of condensed traces of the gunshot residue containing heavy metal compounds on various objects by scanning electron microscopy and X-ray microanalysis»

2021 ◽  
Vol 87 (12) ◽  
pp. 63-72
Author(s):  
S. A. Smirnova ◽  
I. B. Afanasyev ◽  
G. I. Bebeshko ◽  
G. G. Omel’yanyuk
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Standard Sample ◽  
Gunshot Residue ◽  
Test Results ◽  
Metal Compounds ◽  
X Ray ◽  
Scanning Electron

We present and discuss the results of the validation of a forensic qualitative testing technique which consists in the detection of condensed traces of the gunshot residue (GSR) in the form of individual microparticles on the objects under study and their identification by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) using a scanning electron microscope Mira III (Tescan, Czech Republic) equipped with a system of X-ray microanalysis INCA GSR 450 (Oxford Nanoanalysis, Great Britain). The procedure for detecting GSR particles containing heavy metal compounds, systems of their classification and interpretation of test results are described. The suitability of the methodology for solving forensic problems has been confirmed. The validation procedure consists in assessing the reliability by comparing the test results obtained by experts (A and B) in two laboratories at different times using the same device, and in confirming the competence of experts proceeding from the results of blind tests. A standard sample ENFSI GSR PT 2018 A-03-07 is used. Each of the experts determined the number of particles classified as GSR present in control samples taken in a ballistic laboratory during a full-scale experiment: from the hands of the shooter; from the hands of a person who did not shoot; without microparticles (clean stage of an electron microscope). The reliability of the technique is characterized by the index (probability) of correct results of detecting GSR particles in the standard sample of at least 95.8% and by a small proportion of false results (no more than 5.4%). The competence of the experts is proved by the consistent results of «blind» testing of control full-scale samples, containing and not containing GSR particles obtained in different laboratories. The results of the validation indicate the suitability of the method for obtaining reliable and valid information about the presence of GSR particles on the objects under study.

Sign in / Sign up

Export Citation Format

Share Document