scholarly journals Arsenic(v) removal on the lanthanum-modified ion exchanger with quaternary ammonium groups based on iron oxide

2021 ◽  
pp. 117985
Author(s):  
Sebastian Dudek ◽  
Dorota Kołodyńska
Keyword(s):  
Iron Oxide ◽  
Quaternary Ammonium ◽  
Ion Exchanger

Selective Removal of Perfluorobutyric Acid Using an Electroactive Ion Exchanger Based on Polypyrrole@Iron Oxide on Carbon Cloth

2021 ◽  
Author(s):  
Chenxi Huyan ◽  
Shichao Ding ◽  
Zhaoyuan Lyu ◽  
Mark H. Engelhard ◽  
Yuhao Tian ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Selective Removal ◽  
Ion Exchanger ◽  
Carbon Cloth

Sorption and Desorption of a Cationic Polymer by Human Hair: Effects of Salt Solutions

1977 ◽  
Vol 47 (9) ◽  
pp. 616-620 ◽  
Author(s):  
J. A. Faucher ◽  
E. D. Goddard ◽  
R. B. Hannan
Keyword(s):  
Quaternary Ammonium ◽  
Human Hair ◽  
Strong Acid ◽  
Cationic Polymer ◽  
Ion Exchanger ◽  
Cellulose Ether ◽  
Salt Solutions ◽  
Low Concentrations ◽  
Added Salt

Sorption of Polymer JR, a cationic cellulose ether, by human hair is greatly decreased in the presence of added electrolytes. This reflects the competition between cations of the added salt and the quaternary ammonium groups of the polymer for sorption sites in the substrate. In this respect the hair can be regarded as a “strong-acid” ion-exchanger, and it displays a selectivity to ions similar to that observed for conventional resin exchangers. Cations can be ranked in order according to their ability to decrease the sorption of Polymer JR as follows: La+++ > Al+++ < Fe+++ < Ca++ < Fe++ < Cs+ < Na+ < Li+. Salts also promote desorption of Polymer JR that is already sorbed by hair. However, selectivity is less evident in desorption than in sorption and is only observed at relatively low concentrations of salt. About half of the sorbed polymer is readily removed by salt solutions; the rest appears to be tightly attached to the substrate.

Double-barreled K+-selective microelectrodes based on dibenzo-18-crown-6

1988 ◽  
Vol 255 (3) ◽  
pp. C408-C412 ◽  
Author(s):  
J. L. Mooney ◽  
V. Lyall ◽  
M. Acevedo ◽  
W. M. Armstrong
Keyword(s):  
Crown Ether ◽  
Quaternary Ammonium ◽  
Ion Exchanger ◽  
Ammonium Ions ◽  
Neutral Carrier ◽  
Quaternary Ammonium Ions ◽  
Liquid Ion Exchanger

Liquid ion-exchanger microelectrodes based on Corning code 477317 K+ exchanger are known to be much more sensitive to quaternary ammonium ions than to K+. In the presence of such cations, the capability of measuring K+ activities with Corning microelectrodes may be seriously impaired. We have developed a neutral carrier K+-selective microelectrode based on the crown ether dibenzo-18-crown-6. The crown ether cocktail contained (wt/wt) 2.3% dibenzo-18-crown-6, 0.8% Na-tetraphenylborate, 30.1% 2-nitrophenylocylether, and 66.8% O-nitrotoluene. Double-barreled crown ether and Corning microelectrodes were calibrated in KCl solutions with or without choline, acetylcholine, tetramethylammonium, imidazole, Na+, tris(hydroxymethyl)aminomethane (Tris), and N-methyl-D-glucamine. Both kinds of microelectrodes showed similar K+ over Na+, Tris, and N-methyl-D-glucamine selectivities. However, crown ether microelectrodes had immensely greater selectivities of K+ over quaternary ammonium ions and imidazole than Corning microelectrodes. Selectivity factors, defined as log K(ij)K, of crown ether microelectrodes with respect to K+ for tetramethylammonium, choline, acetylcholine, and imidazole were -1.92 +/- 0.13, -2.97 +/- 0.03, -1.75 +/- 0.15, and -1.30 +/- 0.20, respectively. Intracellular K+ activities measured in the same Necturus gallbladders with both kinds of microelectrodes did not differ significantly.

Aqueous natural organic matter removal by quaternary-ammonium-compound-modified iron-oxide-coated sand

2008 ◽  
Vol 8 (5) ◽  
pp. 565-571
Author(s):  
Chunli Ding ◽  
Chii Shang ◽  
Yujung Chang
Keyword(s):  
Organic Matter ◽  
Iron Oxide ◽  
Natural Organic Matter ◽  
Quaternary Ammonium ◽  
Drinking Water Treatment ◽  
Hexadecyltrimethylammonium Bromide ◽  
Ammonium Compound ◽  
Coated Sand ◽  
Positive Effect ◽  
Long Chain

In this study, modification of iron-oxide-coated sand (IOCS) with three quaternary ammonium compounds (QACs) was tested as a means to improve the removal of aqueous natural organic matter (NOM) by IOCS. The assessment was conducted in batch, isotherm setup with changes in types and concentrations of QACs, modification pH, additions of H2O2 during modification, and adsorption pH. IOCS modification with long chain QACs, including hexadecyltrimethylammonium bromide (HDTMA) and hexadecylbenzyldimethylammonium chloride (HDBDMA) significantly increased the adsorption of NOM, while coating IOCS with short chain QAC, tetrapropylammonium chloride (TPA) had no positive effect. The enhancement increased with increasing pH and increasing QAC concentration used during modification. Co-additions of long chain QACs with H2O2 during modification could further improve NOM adsorption. Modification of IOCS with 10.0 mM HDTMA at pH 9.9 with the 0.2% H2O2 addition doubled NOM adsorption capacity on IOCS at pH 9.1. The results presented here suggest that the modification of IOCS using long chain QACs can enhance NOM removal by IOCS during drinking water treatment.

Highly efficient and antibacterial ion exchanger based on graphene oxide for removal of chromate and nitrate from water: synthesis, characterization and application

2021 ◽  
Vol 45 (1) ◽  
pp. 268-281
Author(s):  
Maryam Shojaipour ◽  
Mousa Ghaemy
Keyword(s):  
Graphene Oxide ◽  
Ammonium Chloride ◽  
Anion Exchanger ◽  
Quaternary Ammonium ◽  
Ion Exchanger ◽  
Highly Efficient ◽  
Quaternary Ammonium Chloride

A novel recyclable antibacterial anion exchanger based on graphene oxide (GO) and quaternary ammonium chloride (TMSQA) as a crosslinker/ion exchanger was prepared and used for the removal of chromate and nitrate from water.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

Catalyst- and oxidant-free electrochemical para-selective hydroxylation of N-arylamides in batch and continuous-flow

2020 ◽  
Vol 22 (19) ◽  
pp. 6437-6443
Author(s):  
Cheng-Kou Liu ◽  
Meng-Yi Chen ◽  
Xin-Xin Lin ◽  
Zheng Fang ◽  
Kai Guo
Keyword(s):  
Ammonium Salt ◽  
Quaternary Ammonium ◽  
Continuous Flow ◽  
Quaternary Ammonium Salt ◽  
Selective Hydroxylation

A catalyst-, oxidant-, acidic solvent- and quaternary ammonium salt-free electrochemical para-selective hydroxylation of N-arylamides at rt in batch and continuous-flow was developed.

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