scholarly journals Phosphorylation of Guar Gum/Magnetite/Chitosan Nanocomposites for Uranium (VI) Sorption and Antibacterial Applications

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1920
Author(s):  
Mohammed F. Hamza ◽  
Amr Fouda ◽  
Khalid Z. Elwakeel ◽  
Yuezhou Wei ◽  
Eric Guibal ◽  
...  
Keyword(s):  
Guar Gum ◽  
Sorption Isotherms ◽  
Textural Properties ◽  
Magnetic Composite ◽  
Magnetic Sorbent ◽  
Acidic Solutions ◽  
Valuable Metals ◽  
Maximum Sorption ◽  
Marked Preference ◽  
Solid Liquid

The development of new materials is needed to address the environmental challenges of wastewater treatment. The phosphorylation of guar gum combined with its association to chitosan allows preparing an efficient sorbent for the removal of U(VI) from slightly acidic solutions. The incorporation of magnetite nanoparticles enhances solid/liquid. Functional groups are characterized by FTIR spectroscopy while textural properties are qualified by N2 adsorption. The optimum pH is close to 4 (deprotonation of amine and phosphonate groups). Uptake kinetics are fast (60 min of contact), fitted by a pseudo-first order rate equation. Maximum sorption capacities are close to 1.28 and 1.16 mmol U g−1 (non-magnetic and magnetic, respectively), while the sorption isotherms are fitted by Langmuir equation. Uranyl desorption (using 0.2 M HCl solutions) is achieved within 20–30 min; the sorbents can be recycled for at least five cycles (5–6% loss in sorption performance, complete desorption). In multi-component solutions, the sorbents show marked preference for U(VI) and Nd(III) over alkali-earth metals and Si(IV). The zone of exclusion method shows that magnetic sorbent has antibacterial effects against both Gram+ and Gram- bacteria, contrary to non-magnetic material (only Gram+ bacteria). The magnetic composite is highly promising as antimicrobial support and for recovery of valuable metals.

scholarly journals Effects of food hydrocolloids on quality attributes of extruded red Jasmine rice noodle

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10235
Author(s):  
Supaluck Kraithong ◽  
Saroat Rawdkuen
Keyword(s):  
Guar Gum ◽  
Antioxidant Properties ◽  
Control Sample ◽  
Textural Properties ◽  
Rice Flour ◽  
Total Phenolic ◽  
Phenolic Contents ◽  
Overall Acceptability ◽  
Jasmine Rice ◽  
Diffraction Patterns

The aim of this study was to examine the quality characteristics of extruded red Jasmine rice flour (RJF) noodle that had been prepared with hydrocolloids, namely guar gum (GG), carboxymethyl cellulose (CMC), and xanthan gum (XG) at the concentrations of 0.0 (control sample), 0.2, and 0.4% (w/w), respectively. The use of hydrocolloids had no effect on total phenolic contents, antioxidant properties (DPPH, ABTS, and FRAP), color, and X-ray diffraction patterns (p > 0.05). In contrast, the hydrocolloids tended to increase the expansion ration of the noodle. GG and CMC improved cooking, textural, and sensory properties. Ultimately, 0.2%-GG showed the lowest cooking loss (5.07%) when compared with others. Moreover, it also provided the noodle with better textural properties such as tensile strength, extensibility, hardness, cohesiveness, and chewiness (p < 0.05). For these reasons, the highest acceptability (6.75) for the noodle was achieved with GG02. XG resulted in lower overall acceptability (5.05), particularly the 0.4%-XG recipe (p < 0.05). Thus, usage of 0.2%-GG was the best option for improving the qualities of extruded RJF noodle. XG was deemed ineffective for improving the noodle.

scholarly journals Recovery of Lanthanum(III) and Nickel(II) Ions from Acidic Solutions by the Highly Effective Ion Exchanger

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3718
Author(s):  
Dorota Kołodyńska ◽  
Dominika Fila ◽  
Zbigniew Hubicki
Keyword(s):  
Sorption Process ◽  
Sorption Equilibrium ◽  
Phase Contact Time ◽  
Acidic Solutions ◽  
Dynamic Experiments ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Resin Regeneration ◽  
Sodium Form

The recovery of La(III) and Ni(II) ions by a macroporous cation exchanger in sodium form (Lewatit Monoplus SP112) has been studied in batch experiments under varying HNO3 concentrations (0.2–2.0 mol/dm3), La(III) and Ni(II) concentrations (25–200 mg/dm3), phase contact time (1–360 min), temperature (293–333 K), and resin mass (0.1–0.5 g). The experimental data revealed that the sorption process was dependent on all parameters used. The maximum sorption capacities were found at CHNO3 = 0.2 mol/dm3, m = 0.1 g, and T = 333 K. The kinetic data indicate that the sorption followed the pseudo-second order and film diffusion models. The sorption equilibrium time was reached at approximately 30 and 60 min for La(III) and Ni(II) ions, respectively. The equilibrium isotherm data were best fitted with the Langmuir model. The maximum monolayer capacities of Lewatit Monoplus SP112 were equal to 95.34 and 60.81 mg/g for La(III) and Ni(II) ions, respectively. The thermodynamic parameters showed that the sorption process was endothermic and spontaneous. Moreover, dynamic experiments were performed using the columns set. The resin regeneration was made using HCl and HNO3 solutions, and the desorption results exhibited effective regeneration. The ATR/FT-IR and XPS spectroscopy results indicated that the La(III) and Ni(II) ions were coordinated with the sulfonate groups.

scholarly journals Quaternization of Composite Algal/PEI Beads for Enhanced Uranium Sorption—Application to Ore Acidic Leachate

Gels ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 12 ◽  
Author(s):  
Mohammed F. Hamza ◽  
Amal E. Mubark ◽  
Yuezou Wei ◽  
Thierry Vincent ◽  
Eric Guibal
Keyword(s):  
Ph Effect ◽  
Sorption Isotherms ◽  
Environmental Safety ◽  
Sorption Properties ◽  
Yellow Cake ◽  
Maximum Sorption Capacity ◽  
Copper Precipitation ◽  
Protonated Amine ◽  
Maximum Sorption ◽  
Pre Treatment

The necessity to recover uranium from dilute solutions (for environmental/safety and resource management) is driving research towards developing new sorbents. This study focuses on the enhancement of U(VI) sorption properties of composite algal/Polyethylenimine beads through the quaternization of the support (by reaction with glycidyltrimethylammonium chloride). The sorbent is fully characterized by FTIR, XPS for confirming the contribution of protonated amine and quaternary ammonium groups on U(VI) binding (with possible contribution of hydroxyl and carboxyl groups, depending on the pH). The sorption properties are investigated in batch with reference to pH effect (optimum value: pH 4), uptake kinetics (equilibrium: 40 min) and sorption isotherms (maximum sorption capacity: 0.86 mmol U g−1). Metal desorption (with 0.5 M NaCl/0.5 M HCl) is highly efficient and the sorbent can be reused for five cycles with limited decrease in performance. The sorbent is successfully applied to the selective recovery of U(VI) from acidic leachate of uranium ore, after pre-treatment (cementation of copper, precipitation of rare earth elements with oxalate, and precipitation of iron). A pure yellow cake is obtained after precipitation of the eluate.

scholarly journals Phosphorus Sorption and Redistribution on Soil Solid Phase in a Brazilian Haplorthox Amended with Biosolids

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Ricardo de Oliveira Munhoz ◽  
Ronaldo Severiano Berton ◽  
Otávio Antonio de Camargo
Keyword(s):  
Binding Energy ◽  
Solid Phase ◽  
Sorption Isotherms ◽  
Land Application ◽  
Phosphorus Sorption ◽  
Sequential Fractionation ◽  
Soil P ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
P Fraction

Land application of biosolids (SS) can cause a buildup of phosphorus (P) in the top soil. The changes in the soil P characteristics may be assessed by the sorption isotherm and the sequential fractionation techniques. Samples of Haplorthox were collected from a field experiment where maize was cultivated for two years, after two applications of SS originated from two cities of São Paulo State, Brazil. SS applications added a total of 125, 250, 500, 1000 and 2000 kg ha−1of P in the area. To perform the sorption isotherms and obtain P maximum sorption capacity (Qmax) and the binding energy, soil samples were submitted to increasing P concentration solutions until equilibrium was reached. Sequential fractionation was done by a sequential extraction with CaCl2, NaHCO3, NaOH, HCl, and HNO3+ HClO4(residual). Addition of biosolids from both cities to the soil decreasedQmaxand the binding energy obtained by the Langmuir equation. SS additions changed the P fractions distribution in the soil by increasing the labile fractions (P-CaCl2and P-NaHCO3) and the moderately labile fraction (P-NaOH) by 11.2% and 20.3%, respectively, in detriment of the most resistant P fraction.

Cadmium and Zinc Biosorption by Macrocystis Pyrifera: Changes in the Biomass

2009 ◽  
Vol 71-73 ◽  
pp. 601-604
Author(s):  
J. Plaza ◽  
Eric Guibal ◽  
J.M. Taulemesse ◽  
M. Viera ◽  
Edgardo R. Donati
Keyword(s):  
Cell Wall ◽  
Nitric Acid ◽  
Acid Solution ◽  
Sorption Isotherms ◽  
Macrocystis Pyrifera ◽  
Metal Release ◽  
Metal Sorption ◽  
Acidic Solutions ◽  
Edax Analysis ◽  
Partial Degradation

Macrocystis pyrifera was used for the recovery of Zn2+ and Cd2+ from slightly acidic solutions (i.e., pH 4). Sorption isotherms were obtained from mono- and bi-component solutions. For the study of metal desorption, EDTA, HNO3 and Ca(NO3)2 were used as eluents. Metal release (Ca2+, Mg2+, K+ and Na+) was monitored in order to evaluate ion exchange mechanisms. After metal sorption/desorption steps the sorbent was characterized using SEM-EDAX analysis. SEM-EDAX analysis also allowed identifying the presence of elements such as Si, Al, Co, Ag, S, P, and Fe in the cell wall. Zinc desorption was almost complete when using 0.1 M nitric acid solution and the sorbent was not significantly damaged by the acidic treatment. Cadmium was completely removed from loaded sorbent when using EDTA, but at the expense of a partial degradation of the biomass as evidenced by the decrease in the intensity of the C and O peaks (SEM-EDAX).

Ba(OH)2 as the catalyst in organic reactions. Part XIV. Mechanism of Claisen–Schmidt condensation in solid–liquid conditions

1987 ◽  
Vol 65 (6) ◽  
pp. 1165-1171 ◽  
Author(s):  
A. Aguilera ◽  
A. R. Alcantara ◽  
J. M. Marinas ◽  
J. V. Sinisterra
Keyword(s):  
Infrared Spectroscopy ◽  
Textural Properties ◽  
Organic Reactions ◽  
Barium Hydroxide ◽  
Liquid Reaction ◽  
Solid Liquid

The mechanism of the Claisen–Schmidt condensation, catalyzed by a series of activated barium hydroxide catalysts, is discussed. Two kinds of ketones are studied: R—CO—CH3 (R = Me, Et, Pri, But) and acetophenone (R = Ph). The influence of the chemical and textural properties of the catalysts, as well as the nature of the solvent, are studied. The process is an interfacial solid–liquid reaction between the adsorbed carbanion and the benzaldehyde. The different structures of the adsorbed carbanion produced from Ph—CO—CH3 and R—CO—CH3 are analyzed by infrared spectroscopy, and could explain the different reactivities observed in the process. The kinetic runs are discussed.

Mercury Sorption on Chitosan

2007 ◽  
Vol 20-21 ◽  
pp. 635-638 ◽  
Author(s):  
Karol Campos ◽  
Eric Guibal ◽  
Francisco Peirano ◽  
M. Ly ◽  
Holger Maldonado
Keyword(s):  
Particle Size ◽  
Metal Ion ◽  
Fixed Bed ◽  
Sorption Isotherms ◽  
Sorption Kinetics ◽  
Breakthrough Curves ◽  
Ion Concentration ◽  
Fixed Bed Reactor ◽  
Continuous Systems ◽  
Maximum Sorption

Mercury sorption on chitosan was investigated in batch and continuous systems. Chitosan sorption properties were determined through sorption isotherms. Langmuir and Freundlich equations were used for the modeling of isotherms at pH 5. In batch systems, maximum sorption capacities reached 550 mg Hg/g. Sorption kinetics have been studied as a function of sorbent particle size and stirring rate. Dynamic removal of mercury was tested in a fixed bed reactor investigating the following parameters: particle size, column size, flow velocity and metal ion concentration. Clark and Adams-Bohart models were evaluated for the simulation of breakthrough curves. This study shows that chitosan is an effective sorbent for the treatment and recovery of mercury from dilute effluents at near neutral pH.

scholarly journals Performance of Ag-TiO2Photocatalysts towards the Photocatalytic Disinfection of Water under Interior-Lighting and Solar-Simulated Light Irradiations

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Camilo A. Castro ◽  
Adriana Jurado ◽  
Diana Sissa ◽  
Sonia A. Giraldo
Keyword(s):  
Visible Light ◽  
Singlet Oxygen ◽  
Sorption Isotherms ◽  
Textural Properties ◽  
Bactericidal Effect ◽  
Oxygen Scavenger ◽  
Visible Light Absorption ◽  
Photocatalytic Disinfection ◽  
Interior Lighting ◽  
Inactivation Process

This paper reports the characterization and photoactivity of Ag-TiO2materials using different amounts of silver during the hydrothermal synthesis. Photocatalysts were characterized by means of TEM, XPS, XRD, DRS, and N2sorption isotherms to determine the textural properties. The photocatalyst's configuration was observed to be as anatase-brookite mixed phase particles with Ag partially oxidized aggregates on the TiO2surface, which increased visible light absorption of the material. Moreover, photoproduction of singlet oxygen was followed by EPR analysis under visible light irradiations following the formation of TEMPOL. Such photoproduction was totally decreased by using the singlet oxygen scavenger DABCO. Photocatalysts were tested towards the photocatalytic disinfection of water suing a solar light simulator and an interior-light irradiation setup. Results evidenced an increase in the photooxidative effect of TiO2, while dark processes evidenced that part of the inactivation process is due to the Ag-TiO2surface bactericidal effect and possible lixiviated Ag+.

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