Selenium oxyanions: Highly selective uptake by a novel anion exchanger

2002 ◽  
Vol 17 (12) ◽  
pp. 2993-2996 ◽  
Author(s):  
Naofumi Kozai ◽  
Toshihiko Ohnuki ◽  
Sridhar Komarneni
Keyword(s):  
Anion Exchanger ◽  
High Selectivity ◽  
Contaminated Water ◽  
Basic Salt ◽  
Selective Uptake ◽  
Very High

We report the extremely high and selective uptake of selenium oxyanions by a novel anion exchanger, Ni1-xZn2x(OH)2(OCOCH3)2xnH2O (0.15<x<0.25). The tested Ni–Zn basic salt (x=0.24) exhibited very high selectivity for Se(IV) [Kd = 9.0 × 104 cm3/g with an initial Se(IV) concentration of 1 × 10-4 M] in the presence of 0.1 M C1− solution. The uptake of Se(IV) on the Ni–Zn basic salt was irreversible when treated with solutions containing 1 N C1− 1N NO3− or 1 N PO43−This novel exchanger also showed high Kd (2.6 × 103 cm3/g) for Se(VI), and therefore it is expected to be useful for decontamination and removal of selenium oxyanions from contaminated water.

Microwave-hydrothermal processing of layered anion exchangers

1996 ◽  
Vol 11 (8) ◽  
pp. 1866-1869 ◽  
Author(s):  
Sridhar Komarneni ◽  
Q. H. Li ◽  
Rustum Roy
Keyword(s):  
High Selectivity ◽  
Hydrothermal Processing ◽  
Basic Salt ◽  
Anion Exchangers ◽  
Microwave Hydrothermal ◽  
Order Of Magnitude ◽  
Very High

We have compared the microwave-hydrothermal (M-H) processing with conventional hydrothermal (C-H) processing in the preparation of two layered anion exchangers, i.e., Mg3Al(OH)8NO3 · nH2O and Ni1-xZn2x(OH)2(CH3COO)2x · nH2O. Both these phases can be crystallized more rapidly (an order of magnitude) under M-H processing compared to C-H processing. The above layered mixed basic salt of Ni and Zn was found to exhibit very high selectivity for PO4= (Kd = 15,000). Its order of selectivity for various anions in the presence of 0.1 N̲ NaC1 (ratio of C1- to anion in question is 100) increases as follows: PO4= ≫ SO4= > NO3-.

Synthesis of CuxNi(1−x)O coral-like nanostructures and their application in the design of a reusable toxic heavy metal ion sensor based on an adsorption-mediated electrochemical technique

2017 ◽  
Vol 4 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Sayan Dey ◽  
Sumita Santra ◽  
Anupam Midya ◽  
Prasanta Kumar Guha ◽  
Samit Kumar Ray
Keyword(s):  
Heavy Metal ◽  
Detection Limit ◽  
Metal Ion ◽  
High Selectivity ◽  
Heavy Metal Ion ◽  
Electrochemical Technique ◽  
Toxic Heavy Metal ◽  
Ion Sensors ◽  
Metal Ion Sensors ◽  
Very High

Nanostructured, Cu-doped nickel oxides serve as excellent, ultra-fast, re-usable heavy metal ion sensors with an ultra-low detection limit and very high selectivity towards toxic Cr(vi) ions.

Kinetics of ο-Chloronitrobenzene Hydrogenation on Palladium/Carbon Catalyst

2011 ◽  
Vol 239-242 ◽  
pp. 161-167
Author(s):  
Xiao Zhen Wang ◽  
Yi Feng Zhu ◽  
Xiao Nian Li
Keyword(s):  
High Selectivity ◽  
Total Yield ◽  
Hydrogenation Reaction ◽  
Commercial Application ◽  
Reaction Conditions ◽  
Solvent Free Conditions ◽  
Hydrogenation Kinetics ◽  
Favorable Reaction ◽  
Kinetics Of ◽  
Very High

A 2 wt % Pd/C catalyst has been prepared by chemical impregnation and used to catalyze the hydrogenation of o-chloronitrobenzene (o-CNB) to o-chloroaniline (o-CAN) in solvent-free conditions. The effects of reaction temperature, H2 pressure, and stirring intensity on the hydrogenation kinetics have been investigated. The hydrogenation reaction showed very high selectivity with dehalogenation side products as low as 0.3% of total yield. The favorable reaction conditions were found to be temperature T = 383 K, stirring speed = 900 rpm, and feeding ratio CNB/catalyst = 200/1 (m/m). The recycled Pd/C still retained more than 98% of its original selectivity after 12 repeat used, indicating the catalyst had strong potentials for commercial application at industrial scale.

Kinetics of 2-Chloro-6-Nitrotoluene Hydrogenation on Palladium/Carbon Catalyst without Inhibitors

2012 ◽  
Vol 487 ◽  
pp. 107-110
Author(s):  
Feng Wen ◽  
Yi Feng Zhu ◽  
Xiao Nian Li
Keyword(s):  
Activation Energy ◽  
High Selectivity ◽  
Hydrogenation Reaction ◽  
Zero Order ◽  
Carbon Catalyst ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Favorable Conditions ◽  
Kinetics Of ◽  
Very High

Pd-only catalyst supported on activated carbon has been prepared by chemical impregnation and used to catalyze the hydrogenation of 2-chloro-6-nitrotoluene (2-CNT) to 3-chloro-2-methylaniline in solvent-free condition. The effects of reaction temperature，H2 pressure on the hydrogenation have been investigated. The reaction showed very high selectivity with the dehalogenation side product with a yield of less than 1.2 %. The most favorable conditions could be temperature= 353 K, stirring speed= 1200 rpm, H2 pressure= 1 MPa. The catalytic hydrogenation reaction was found to have a zero order with hydrogen and 1 order with 2-CNT. The apparent activation energy of the hydrogenation was 60.58 kJ/mol.

PURIFICATION OF LYSOZYME BY INTRINSICALLY SHIELDED HYDROGEL BEADS

2013 ◽  
Vol 27 (19) ◽  
pp. 1341028
Author(s):  
CONG LI ◽  
R. ZHANG ◽  
L. WANG ◽  
A. BOWYER ◽  
R. EISENTHAL ◽  
...  
Keyword(s):  
Binary Mixture ◽  
High Purity ◽  
High Selectivity ◽  
Egg White ◽  
Titration Calorimetry ◽  
Binding Affinities ◽  
Affinity Separation ◽  
Hydrogel Beads ◽  
Relative Binding ◽  
Very High

Macro-sized intrinsically shielded hydrogel beads have been prepared from BSA and CM-dextran grafted with CB using a technique based on freeze-thawing gelation method. The size of the beads lies in around 500 μm. Isothemal titration calorimetry (ITC) showed that the relative binding affinities of the lysozyme for CB, compared with BSA, at pH 3.0 was stronger than that at pH 7.4. They were employed for the affinity separation of lysozyme using chromatography column. Their adsorption capacity for lysozyme at pH 3.0 is higher than that at pH 9. In a binary mixture of lysozyme and ovalbumin, the beads showed very high selectivity toward lysozyme. Lysozyme of very high purity (> 93%) was obtained from a mixture of lysozyme and ovalbumin, and 85% from egg white solution. The results indicate that the macro-sized bead can be used for the separation, purification, and recovery of lysozyme in a chromatograph column.

scholarly journals A Z-scheme photocatalyst constructed with an yttrium–tantalum oxynitride and a binuclear Ru(ii) complex for visible-light CO2 reduction

2016 ◽  
Vol 52 (50) ◽  
pp. 7886-7889 ◽  
Author(s):  
Kanemichi Muraoka ◽  
Hiromu Kumagai ◽  
Miharu Eguchi ◽  
Osamu Ishitani ◽  
Kazuhiko Maeda
Keyword(s):  
Visible Light ◽  
Band Gap ◽  
High Selectivity ◽  
Co2 Reduction ◽  
Very High ◽  
Hybrid Photocatalyst

A hybrid photocatalyst composed of an yttrium–tantalum oxynitride (with a 2.1 eV band gap) and a binuclear Ru(ii) complex containing both photosensitizing and catalytic units was capable of reducing CO2 to HCOOH with very high selectivity (>99%) under visible light (>400 nm) irradiation.

Design of the Compact Parallel Coupled Wideband Bandpass Filter With Very High Selectivity and Wide Stopband

2007 ◽  
Vol 17 (7) ◽  
pp. 510-512 ◽  
Author(s):  
Cheng-Yuan Hung ◽  
Min-Hang Weng ◽  
Ru-Yuan Yang ◽  
Yan-Kuin Su
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Very High
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