• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.75-80
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• 1998

Ammonium ion is notorious for the adverse effects upon many of the important uses of water such as toxcity to fish, corrosion of metals and concrete, and concern over man's consumption. A clinoptilolite, which is a naturally occurring zeolite selective for ammonium ion exchange, has been used. Batch isotherm experiments were conducted for measuring ammonium ion exchange capacity. The ion exchange capacity was well described either by the Langmuir equation or by the Freundlich equation. As the particle size of the clinoptilolite decreased, exchange capacity was increased. The smaller particle size enhaced the exchange of ammonium ion due to the greater surface area and decreased diffusion to the exchange sites within the zeolite. Ammonium ion exchange capacity tended to decrease when the temperature increased from $20^{\circ}C$ to $35^{\circ}C$, and the temperature correction factor was found to be 0.98 in the Langmuir equation.

• Journal of environmental and Sanitary engineering
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• v.23 no.1
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• pp.67-72
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• 2008

Ion exchange performance to remove Ammonium in water was studied using commercially available strong acidic cationic exchange resin of $Na^+$ type in the batch and continuous column reactors. The performance was tested using the effluent concentration histories for continuous column or equilibrium concentrations for batch reactor as a function of time until resins were exhausted or reached ionic equilibrium between resin and solution. The results shoed that cationic exchange resin used in this study was more effective than activated carbon or zeolite for ammonium removal. Ammonium removal with the ion exchange resin temperature to be high qualitative recording minuteness but increases about seasonal change of temperature was judged with the public law where the adaptability is excellent. When the pH comes to be high at 11 degree, the ammonium was not effectively removed.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.750-757
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• 2009

The ammonium ion exchange characteristics of natural zeolite were investigated to remove ${NH_4}^+-N$. The effect of water temperature, particle size and competitive cation on the exchange capacity was examined. Ammonium ion exchange capacity tended to decrease when the temperature increased from $25^{\circ}C$ to $40^{\circ}C$. Exchange capacity was increased according to the particle size of natural zeolite comes to be small. Batch isotherm experiments were conducted for measuring ammonium ion exchange capacity. The ion exchange capacity was well described either by the Langmuir isotherm model or by the Freundlich isotherm model. The ammonium ion exchange capacity ($q_m$) of zeolite carrier can be calculated $11.744mg-{NH_4}^+/g$-carrier. The ion exchange capacity of manufactured zeolite carrier was showed a similar tendency as ion exchange capacity of powder-sized natural zeolite. Therefore, zeolite carrier can be used for increasing of nitrogen removal efficiency in the wastewater treatment plants.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.49-54
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• 2012

Various anion exchange membranes were prepared by radiation graft copolymerization of vinylbenzyl chloride onto fluorinated films and subsequent quaternization with various tertiary amines such as trimethylamine, N,N-dimethylbuthylamine, N,N-dimethylaniline, and N-methylpiperidine. The quaternizations of the anion exchange membranes were confirmed by measuring of the ion exchange capacities of the membranes. The mechanical properties and the water uptakes were also measured. The elongation at break was found to be largely dependent on the fluorinated film, the quateranry ammonium, and the degree of grafting. The results indicate that the poly (ethylene-alt-tetrafluoroethylene) with quaternized trimethylamine moiety exhibits higher flexible property compared to the other prepared anion exchange membranes.

• Asian Journal of Atmospheric Environment
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• v.5 no.2
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• pp.134-143
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• 2011

The present study aimed to investigate the diurnal variations in air concentrations and exchange fluxes of ammoniacal nitrogen ($NH_x$: ammonia ($NH_3$) and particulate ammonium) in a subalpine deciduous forest in central Japan during a week in summer. The $NH_3$ concentrations ($0.50\;{\mu}g\;N\;m^{-3}$ on average) showed a clear circadian variation, i.e., high and low in the daytime and nighttime, respectively. The concentration of particulate ammonium in the coarse fractions was extremely low, whereas that for the PM2.5 fraction was relatively high $0.55\;{\mu}g\;N\;m^{-3}$ on average). The main inorganic ion components of PM2.5 at the study site were ammonium and sulfate. The exchange fluxes of $NH_x$ were bidirectional. Both the maximum and minimum values occurred in the daytime, i.e., $0.39\;mg\;N\;m^{-2}\;hr^{-1}$ of downward flux and $0.11\;mg\;N\;m^{-2}\;hr^{-1}$ of upward flux for $NH_3$ and $0.25\;mg\;N\;m^{-2}\;hr^{-1}$ of downward flux and $0.13\;mg\;N\;m^{-2}\;hr^{-1}$ of upward flux for PM2.5 ammonium. The exchange fluxes of $NH_x$ at night could be considered as zero. The mean deposition velocity during the research period was almost zero for both $NH_3$ and PM2.5 ammonium. The atmosphere-forest exchange of $NH_x$ in the forest during the study period was balanced. The remarkably large deposition of $NH_x$ was attributable to meteorological events such as showers the night before that thoroughly washed the forest canopy and subsequent clear skies in the morning, which enhanced convection. The cleaning effect of rainfall and the rapid change in convection in the early morning should be monitored to evaluate and generalize the gas and particle exchange in a forest.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.181-187
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• 2014

This study was performed to identify the optimum fractionation method and conditions to obtain exopeptidase-active fractions from octopus hepatopancreas (HP) crude extracts (CEs) using four techniques: solid ammonium sulfate fractionation, polyethylene glycol (PEG) fractionation, anion exchange chromatography, and gel filtration chromatography. The fractions with the highest total activity toward L-leucine-p-nitroanilide (Leu-pNA) were fraction IV from the ammonium sulfate and PEG fractionation, and fraction II in ion exchange and gel filtration chromatography. The total exoprotease activity of these fractions was highest in fraction IV (4,050.20 U) of ammonium sulfate fractionation, followed by fraction II (3,600.28 U) from gel filtration chromatography, fraction IV (2,861.30 U) from PEG fractionation, and fraction II (2,576.28 U) from ion exchange chromatography. These results suggest that ammonium sulfate fractionation using 60-80% ammonium sulfate was the most efficient method for separating the exoprotease active fractions from CEs of octopus HP.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.435-442
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• 2000

Batch test and column test were performed to develop the design factors for permeable reactive barriers(PRBs) against ammonium and heavy metals, Clinoptilolite, a kind of natural zeolites having excellent cation exchange capacity(CEC), was choosen for the reacting materials through the ion-exchange mechanism. In the batch test, the reactivity of clinoptilolite for ammonium, lead, and copper was examined varying the initial concentration of contaminants(ammonium: 20, 40, 80 ppm, heavy metals: 10, 20, 40 ppm) and the particle size of clinoptilolites(0-0.15, 0.42-0.85, 1-1.25 mm). The reactivity is increasing as the initial concentration decrease and particle size decrease. In the column test, the permeability and the reactivity of the specimens were examined using flexible-wall permeameter. Specimens were made of clinoptilolite and Jumunjin-sand with 20 : 80 weight ratio varying particle size of clinoptilolite. The maximum permeability(1${\times}$10$\^$-4/-5${\times}$10$\^$-5/cm/s) was achieved in the specimen made of 0.42-0.85 mm clinoptilolite and sand.

• Journal of the Korean Applied Science and Technology
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• v.25 no.1
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• pp.65-72
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• 2008

The ion exchangers supported on silica gel containing primary, secondary, or tertiary amine groups show a behaviour that is weakly acidic, while the quaternary salts are strongly acidic. These properties change according to the hydrophilicities of the modifier functional groups. Ammonium salt derivatives supported on silica gel were prepared from silica modified with 3-Aminopropyltriethoxysiliane and N-3-(Trimethoxysilyl)propylehtylene diamine. The preparation and the ion exchange properties of two systems were discussed. Two systems have different hydrophilicities and contain ammonium chloride derivatives of 3-amminopropyltriethoxysilane and N-3-(triehtoxysilyl)propyl ethylene diamine supported on silica gel, $SA^+/Cl^-$ and $SA^+/Cl^-$, respectively. The high affinity to perchlorate ion presented by the $SA^+/Cl^-$ through the equilibrium studies of ion exchange led us to its application as an ion selective electrode for the perchlorate ion. The determination of the perchlorate ion in the presence of other anions and in complexes is very difficult. Few analytical methods are available and most of them are indirect. Both materials showed potential use as an ion exchanger; they are thermically stable, achieve equilibrium rapidly in the presence of suitable exchanger ions, and are easily recovered.

• Resources Recycling
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• v.27 no.2
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• pp.48-54
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• 2018

Batch ion exchange experiments of Au(III) were performed from ammonium chloride solution by employing strong anionic exchange resins (Amberlite IRA 402 and AG 1-X8). Au(III) was well loaded into the two resins and the loading behavior of Au(III) into AG 1-X8 was superior to that into Amberlite IRA 402. The loading of Au(III) into AG 1-X8 followed Langmuir adsorption isotherm and the experimentally determined loading capacity was 355 mg/g. Au(III) was successfully eluted by $HClO_4$ from the loaded AG 1-X8 and the elution percentage of Au(III) increased with the concentration of $HClO_4$.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.81-85
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• 2002

A marine bacterium producing superoxide dismutase, strain number B446, was screened with nitrite quantitation method using hydroxy amine and photochemically generated superoxide ion, and the superoxide dismutase was purified through 35-75% ammonium sulfate precipitation, DEAE-Sephadex A-25 ion exchange chromatography, Sephadex G-200 gel filtration chromatography, and High-Q anion exchange chromatography to a yield of 6% and purification fold of 32.3.