scholarly journals Titration of weak base fibrous anion exchangers in the presence of complex-forming divalent cations

2021 ◽  
Vol 57 (4) ◽  
pp. 391-399
Author(s):  
V. S. Soldatov ◽  
L. N. Shachenkova ◽  
E. G. Kasandrovich ◽  
P. V. Nesteronok
Keyword(s):  
Functional Groups ◽  
Divalent Cations ◽  
Polyacrylonitrile Fiber ◽  
Ion Exchangers ◽  
Polymer Complexes ◽  
Maximum Sorption Capacity ◽  
Wide Range ◽  
Maximum Sorption ◽  
Fibrous Ion Exchangers ◽  
Metal Polymer

Curves of potentiometric titration of fully protonized fibrous ion exchangers with potassium hydroxide against the background of 1 M KCl in the presence of chlorides of Ni2+, Со2+, Сu2+ and Ca2+ were obtained. The ion exchangers were synthesized by modifying of industrial polyacrylonitrile fiber with diethylenetriamine and triethylenetetraamine and predominantly contained functional groups R-CO-NH- (CH2CH2NH)nH (n = 2 or 3) and a small amount of carboxyl groups. The sorption of Ni2+, Со2+, Сu2+ и Ca2+by ion exchangers was calculated from the data obtained depending on the pH of the medium. It was found that the investigated ion exchangers with high selectivity sorb heavy metal ions in a wide range of acidity of solutions (pH 2–9) due to the formation of metal-polymer complexes with polyamine functional groups. The maximum sorption capacity is 1.5–2.7 and 4–5 meq/g for ion exchangers with n = 2 and 3, respectively.

Rapid Removal of Methylene Blue in Water Using Polymer-Based Biochar Nanocomposite-Coated Filters

2021 ◽  
Vol 324 ◽  
pp. 116-124
Author(s):  
Edgar Clyde R. Lopez ◽  
Nathaniel M. Saporsantos ◽  
William Ven R. Magbalon ◽  
Richard C. Aquino ◽  
Miguel Lawrence Keith S.J. Celebre ◽  
...  
Keyword(s):  
Dip Coating ◽  
Operating Conditions ◽  
Poly Vinyl Alcohol ◽  
Maximum Sorption Capacity ◽  
Wide Range ◽  
Maximum Sorption ◽  
Initial Ph ◽  
Coating Method ◽  
Dip Coating Method ◽  
The Impact

In this study, the effectiveness of novel nanocomposite-coated filters consisting of biochar (BC) functionalized with sodium alginate (SA) and poly (vinyl alcohol) (PVA) was investigated for methylene (MB) blue removal. The filters were fabricated via a dip-coating method and SEM and FTIR spectroscopy confirmed the successful coating of the filters. The impact of the nanocomposite formulation and the operating parameters (initial pH and MB concentration) on the performance of the coated filters were studied. A nanocomposite composition consisting of 1.0 wt.% SA, 2.0 wt.% PVA, and 1000 ppm BC were found to be optimum, reaching as high as 96.51% MB removal. The fabricated filters were determined to be robust over a wide range of pH and initial MB concentrations. The Sips isotherm model proved to be the best-fit model for MB adsorption, where chemisorption dominates at low MB concentrations, while physisorption dominates at high MB concentrations. The filters have a maximum sorption capacity of 54.5198 mg g-1 and showed good reusability. Overall, our synthesized SA/PVA/BC-coated filters can be used to effectively remove dyes in wastewater over a wide range of operating conditions.

Efficient uptake of perrhenate/pertechnenate from aqueous solutions by the bifunctional anion-exchange resin

2018 ◽  
Vol 106 (7) ◽  
pp. 581-591 ◽  
Author(s):  
Jie Li ◽  
Lin Zhu ◽  
Chengliang Xiao ◽  
Lanhua Chen ◽  
Zhifang Chai ◽  
...  
Keyword(s):  
Anion Exchange ◽  
High Selectivity ◽  
Sorption Properties ◽  
Maximum Sorption Capacity ◽  
Anion Exchange Resins ◽  
Wide Range ◽  
Maximum Sorption ◽  
Chain Group ◽  
Efficient Uptake ◽  
Exchange Resins

Abstract In this work, batch experiments were carried out to explore the sorption properties for perrhenate (ReO4−, a surrogate for TcO4−) by two types of commercial bifunctional anion-exchange resins (Purolite A530E and A532E). It is found that these two bifunctional anion-exchange resins could rapidly remove ReO4− from aqueous solution within 150 min and the maximum sorption capacity for ReO4− reached as high as 707 and 446 mg/g for Purolite A530E and A532E, respectively. The sorption properties were independent of pH over a wide range from 1 to 13. More importantly, both Purolite A530E and A532E exhibited excellent selectivity for the removal of ReO4− in the presence of large excess of NO3− and SO42−. Finally, the removal percentage of ReO4− by these two resins could be >90% and 80%, respectively, from the Hanford low-level waste melter off-gas scrubber simulant stream. Such high selectivity of Purolite A530E and A532E for the removal of ReO4− might be due to the presence of the long-chain group of –[N(Hexyl)3]+, which favored hydrophobic and large anions such as ReO4−/TcO4− rather than NO3−.

scholarly journals Metal-Polymer Complexes of Gallium/Gallium-68 with Copolymers of N-Vinylpyrrolidonewith N-Vinylformamideand N-Vinyliminodiacetic Acid: A Hint for Radiolabeling of Water-Soluble Synthetic Flexible Chain Macromolecules

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2889
Author(s):  
Nikolay I. Gorshkov ◽  
Аndrey Yu. Murko ◽  
Iirina I. Gavrilova ◽  
Мarina А. Bezrukova ◽  
Аlbert I. Kipper ◽  
...  
Keyword(s):  
Water Soluble ◽  
Size Exclusion ◽  
Optical Methods ◽  
Polymer Complex ◽  
Polymer Complexes ◽  
Wide Range ◽  
Exclusion Chromatography ◽  
Gallium 68 ◽  
Metal Polymer

Copolymer of N-vinylpyrrolidone (VP) with vinylformamide (VFA) and N-vinyliminodiacetic acid (VIDA) was synthesized; its metal-polymer complexes (MPCs) with gallium were obtained. The complexes were characterized by size exclusion chromatography, hydrodynamic and optical methods, scanning electron microscopy, and spectral methods (UV, IR, 1Н NMR spectroscopy). It was demonstrated that in going from polymer to complex, hydrodynamic parameters of macromolecules change only slightly, although the polymer contains intramolecular Ga(VIDA)2 fragments in its structure. A new method for preparation of MPCs with gallium and gallium-68 radionuclide was suggested. The obtained metal-polymer complex is stable over a wide range of pH values as well as in the histidine challenge reaction. In vivo distribution experiments in intact animals showed high primary accumulation of thegallium-68 MPC in blood with subsequent excretion via urinary tract.

scholarly journals Titration of chelating fibrous sorbent in the presence of complex-forming divalent cations

2021 ◽  
Vol 57 (3) ◽  
pp. 263-269
Author(s):  
V. S. Soldatov ◽  
T. A. Korshunova ◽  
E. G. Kosandrovich ◽  
P. V. Nesteronok
Keyword(s):  
Metal Ion ◽  
Potassium Hydroxide ◽  
Equilibrium Solution ◽  
Divalent Cations ◽  
Polyacrylonitrile Fiber ◽  
Ph Values ◽  
Titration Curves ◽  
Chelating Sorbent ◽  
Back Titration ◽  
Maximum Sorption

Titration curves of H-forms of the fibrous chelating sorbent with iminodiacetic groups based on industrial polyacrylonitrile fiber Nitron with potassium hydroxide in 1M KCl solution in the presence of Ni2+, Co2+, Cu2+ and Ca2+ chlorides were obtained. The method used made it possible to simultaneously measure the pH of the solution and the concentration of the divalent cation at each point of the titration curve. From these data, the dependences of their sorption values on the pH of the equilibrium solution were calculated. The curves of direct and back titration practically coincided in all cases. As the pH changed during titration, precipitation was observed at pH values of precipitation of the corresponding hydroxides. In this case, the increase in pH was suspended or greatly slowed down by adding alkali to the titration cell. The formation of a precipitate occurred mainly in a solution for Co2+ and Ni2+ (pH 8), when the ion exchanger was saturated with a metal ion. In the case of Cu2+ (precipitate formation pH 4), Cu2+ sorption occurs at both lower and higher pH due to ionization of carboxyl groups and partial dissolution of the precipitate. In all cases, the maximum sorption of Ni2+, Co2+, Cu2+, Ca2+ corresponded to the formation of sorption complexes of the R–N(CH2COO-)2Me2+ type.

Природные материалы для сорбционной очистки хром- и кадмийсодержащих инфильтратов полигонов ТБО

2019 ◽  
pp. 13-19
Author(s):  
A. Safonov ◽  
N. Andriushchenko ◽  
N. Popova ◽  
K. Boldyrev
Keyword(s):  
Sorption Capacity ◽  
Electron Acceptors ◽  
Bacterial Cells ◽  
Maximum Sorption Capacity ◽  
Sorption Material ◽  
Maximum Sorption ◽  
Properties Of Materials ◽  
Solid Waste Landfills ◽  
Sorption Characteristics

Проведен анализ сорбционных характеристик природных материалов (вермикулит, керамзит, перлит, цеолит Трейд ) при очистке кадмий- и хромсодержащих сточных вод с высокой нагрузкой по ХПК. Установлено, что цеолит обладает максимальными сорбционными характеристиками для Cd и Cr и наименьшим биологическим обрастанием. При использовании вермикулита и керамзита или смесей на их основе можно ожидать увеличения сорбционной емкости для Cd и Сr при микробном обрастании, неизбежно происходящем в условиях контакта с водами, загрязненными органическими соединениями и биогенами. При этом биообрастание может повысить иммобилизационную способность материалов для редоксзависимых металлов за счет ферментативных ресурсов бактериальных клеток, использующих их в качестве акцепторов электронов. Эффект микробного обрастания разнонаправленно изменял параметры материалов: для Cr в большинстве случаев уменьшение и для Cd значительное увеличение. При этом дополнительным эффектом иммобилизации Cr является его биологическое восстановление биопленками. Варьируя состав сорбционного материала, можно подбирать смеси, оптимально подходящие для очистки вод инфильтратов с полигонов твердых бытовых отходов с высокой нагрузкой по ХПК и биогенным элементам как при использовании in situ, так и в системах на поверхности.The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, Trade zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.

scholarly journals Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

2021 ◽  
Vol 13 (3) ◽  
pp. 1502
Author(s):  
Maria Xanthopoulou ◽  
Dimitrios Giliopoulos ◽  
Nikolaos Tzollas ◽  
Konstantinos S. Triantafyllidis ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Removal Rate ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Equilibrium Studies ◽  
Maximum Sorption Capacity ◽  
Algae Blooms ◽  
Maximum Sorption ◽  
Phosphate Anions ◽  
Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

scholarly journals Rheology and Water Absorption Properties of Alginate–Soy Protein Composites

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1807
Author(s):  
Estefanía Álvarez-Castillo ◽  
José Manuel Aguilar ◽  
Carlos Bengoechea ◽  
María Luisa López-Castejón ◽  
Antonio Guerrero
Keyword(s):  
Soy Protein ◽  
Water Solubility ◽  
Divalent Cations ◽  
Low Cost ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Guluronic Acid ◽  
Wide Range ◽  
Anionic Polysaccharides ◽  
Porous Matrices

Composite materials based on proteins and carbohydrates normally offer improved water solubility, biodegradability, and biocompatibility, which make them attractive for a wide range of applications. Soy protein isolate (SPI) has shown superabsorbent properties that are useful in fields such as agriculture. Alginate salts (ALG) are linear anionic polysaccharides obtained at a low cost from brown algae, displaying a good enough biocompatibility to be considered for medical applications. As alginates are quite hydrophilic, the exchange of ions from guluronic acid present in its molecular structure with divalent cations, particularly Ca2+, may induce its gelation, which would inhibit its solubilization in water. Both biopolymers SPI and ALG were used to produce composites through injection moulding using glycerol (Gly) as a plasticizer. Different biopolymer/plasticizer ratios were employed, and the SPI/ALG ratio within the biopolymer fraction was also varied. Furthermore, composites were immersed in different CaCl2 solutions to inhibit the amount of soluble matter loss and to enhance the mechanical properties of the resulting porous matrices. The main goal of the present work was the development and characterization of green porous matrices with inhibited solubility thanks to the gelation of alginate.

Preparation of Functionalized Diorganomagnesium Reagents in Toluene via Bromine or Iodine/Magnesium-Exchange Reactions

Synthesis ◽  
2021 ◽  
Author(s):  
Alexandre Desaintjean ◽  
Fanny Danton ◽  
Paul Knochel
Keyword(s):  
Exchange Reaction ◽  
Nitro Group ◽  
General Formula ◽  
Functional Groups ◽  
Exchange Reactions ◽  
Acyl Chlorides ◽  
Aryl Iodides ◽  
Highly Sensitive ◽  
Wide Range ◽  
Magnesium Exchange

A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents were prepared in toluene within 10 to 120 min between −78 °C and 25 °C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2Mg (R = sBu, Mes). Highly sensitive functional groups, such as a triazene or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arenes and alkenes derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides.

scholarly journals Modified Exfoliated Carbon Nanoplatelets as Sorbents for Ammonium from Natural Mineral Waters

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3541
Author(s):  
Ion Ion ◽  
Daniela Bogdan ◽  
Monica Maria Mincu ◽  
Alina Catrinel Ion
Keyword(s):  
Natural Waters ◽  
Mineral Waters ◽  
Aqueous Samples ◽  
Sorption Mechanism ◽  
Characteristic Parameters ◽  
Sorption Characteristic ◽  
Natural Mineral ◽  
Maximum Sorption Capacity ◽  
Ammonium Removal ◽  
Maximum Sorption

In this manuscript an improved sorbent based on modified exfoliated carbon nanoplatelets, applied in the removal of ammonium from aqueous samples, is presented. This sorbent showed better efficiency in comparison with the previous one obtained in our group for ammonium removal, the values of the maximum sorption capacity being improved from 10 to 12.04 mg/g. In terms of kinetics and sorption characteristic parameters, their values were also improved. Based on these results, a sorption mechanism was proposed, taking into account ion-exchange and chemisorption processes at the surface of the oxidized exfoliated carbon nanoplatelets. Future applications for simultaneous removal of other positive charged contaminants from natural waters might be possible.

scholarly journals A Mixed Numerical-Experimental Method to Characterize Metal-Polymer Interfaces for Crash Applications

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 818
Author(s):  
Jonas Richter ◽  
Moritz Kuhtz ◽  
Andreas Hornig ◽  
Mohamed Harhash ◽  
Heinz Palkowski ◽  
...  
Keyword(s):  
Experimental Parameter ◽  
Dissimilar Materials ◽  
Calibration Method ◽  
Parameter Determination ◽  
Failure Behavior ◽  
Cohesive Elements ◽  
Interface Failure ◽  
Wide Range ◽  
Polymer Metal ◽  
Metal Polymer

Metallic (M) and polymer (P) materials as layered hybrid metal-polymer-metal (MPM) sandwiches offer a wide range of applications by combining the advantages of both material classes. The interfaces between the materials have a considerable impact on the resulting mechanical properties of the composite and its structural performance. Besides the fact that the experimental methods to determine the properties of the single constituents are well established, the characterization of interface failure behavior between dissimilar materials is very challenging. In this study, a mixed numerical–experimental approach for the determination of the mode I energy release rate is investigated. Using the example of an interface between a steel (St) and a thermoplastic polyolefin (PP/PE), the process of specimen development, experimental parameter determination, and numerical calibration is presented. A modified design of the Double Cantilever Beam (DCB) is utilized to characterize the interlaminar properties and a tailored experimental setup is presented. For this, an inverse calibration method is used by employing numerical studies using cohesive elements and the explicit solver of LS-DYNA based on the force-displacement and crack propagation results.

Sign in / Sign up

Export Citation Format

Share Document