• Journal of Photoscience
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• v.6 no.3
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• pp.91-96
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• 1999

Zeolites and microporouos materials continue to attract attention as novel hosts for photochemical reactions. Zeolities are attractive because of their ability to selectivity exchange and incorporate species within the void spaces and interconnecting channels, providing a spatial arrangement of molecules. Our research has primarily focused on intrazeolitic electron transfer from excited Ru(bpy)32+ in supercages of zeolite Y to a series of bipyridinium ions. In the Ru(bpy)32+ viologen-zeolite Y samples, the slowing of the back electron transfer from the bipyridinium radical cation to Ru(bpy)32+ allows for charge propagation via self exchange between diquat molecules. This provides an opportunity for permanent charge separation. When the migrating charge on the diquat radical within the zeolite reaches the surface, it can be transferred to a neutral viologen (PVS) in solution, resulting in permanent charge separation. The advantage of long-lived charge separation can be exploited for useful chemistry if suitable catablysts can be assembled on the zeolities. We have studied Ru(bpy)2 as water oxdiation catalysts. We have demonstrated that synthesis of RuO2 fibers on a zeolite via thermal decomposition of Ru3(CO)12 leads to the most active water decomposition catalyst reported to date. Because of the extensive interest of photochemical water reduction to H2, much is known about catalytic systems usin gone electron catalyst, and even more importantly, that no reaction of viologen occurred with H2 over this catalyst. The present challenge is to incorporate all these elements of the system into an architecture and we are examining zeolite membranes for this purpose.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.316-320
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• 1987

In order to determine effects of molinate mixture granular formulations on release rate and weed control efficacy of herbicides and growth of rice plants, zeolite impregnation, slurry, and sand-coating granules were tested in laboratory and greenhouse. Release rate of molinate and simetryn was faster in sand-coating granule than in zeolite impregnation and slurry type granules. Mixture granular formulations of molinate/simetryn or molinate/simetryn/MCPB showed good weed control efficacy and this trend was more remarkably shown in sand-coating granule. Sand-coating granule more inhibited growth of rice plants compared to zeolite impregnation and slurry type granules.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.719-728
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• 2017

In order to investigate the adsorption characteristics for Sr ion using the Na-X zeolite synthesized from coal fly ash, batch tests and response surface analyses were carried out. The adsorption kinetic data for Sr ions, using Na-X zeolite, fitted well with the pseudo-second-order model. The uptake of Sr ions followed the Langmuir isotherm model, with a maximum adsorption capacity of 196.46 mg/g. Thermodynamic studies were conducted at different reaction temperatures, with the results indicating that Sr ion adsorption by Na-X zeolite was an endothermic (${\Delta}H^o$>0) and spontaneous (${\Delta}G^o$<0) process. Using the response surface methodology of the Box-Behnken method, initial Sr ion concentration ($X_1$), initial temperature ($X_2$), and initial pH ($X_3$) were selected as the independent variables, while the adsorption of Sr ions by Na-X zeolite was selected as the dependent variable. The experimental data fitted well with a second-order polynomial equation by multiple regression analysis. The value of the determination coefficient ($R^2=0.9937$) and the adjusted determination coefficient (adjusted $R^2=0.9823$) was close to 1, indicating high significance of the model. Statistical results showed the order of Sr removal based on experimental factors to be initial pH > initial concentration > temperature.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.685-690
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• 2017

Ammonia is a useful substance which is widely used in various industries. It is generally released by the decomposition of agricultural wastes and known to have toxic effects on human beings. Due to the common usage, it is possible to cause water pollution through either direct or indirect leakage. Such cases, it is preferable to use the adsorption capacity of zeolite to rapidly remove ammonium ions, but it is not sufficiently removed by the adsorption only. In this paper, the removal efficiency of ammonium ion through both the adsorption capacities of commercial synthetic zeolites and the biological mechanism of microorganisms were compared. In addition, microorganisms were immobilized on the zeolite in order to enhance the removal efficiency by applying a chemo-biological process. As a result, the standard commercial zeolite showed 67~81% of the removal efficiency in 2~4 hours at a 100 ppm concentration of ammonium, whereas the selected microorganism Klebsiella pneumoniae subsp. Pneumoniae showed up to 97% within 8 hours. When the microorganism was immobilized on the zeolite, the highest removal efficiency of approximately 98.5% were observed within 8 hours.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.555-564
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• 2005

This study was conducted to investigate the effect of dietary supplementation of zeolite on growth performance, carcass characteristics and fecal ammonia gas release in the finishing pigs. A total of 120 crossbred finishing pigs (50.2$\pm$1.4kg, Landrace$\time$Yorkshire$\time$Duroc) were assigned to 4 treatments and randomly divided into 12 groups. They were divided between early finishing period (50~80kg) and late finishing period (80-120kg). Finishing pigs were fed on a basal diet supplemented with 0, 1, 2 and 4% levels of zeolite. Average daily gain and feed conversion were significantly (P<0.05) improved by the dietary supplementation of 4% zeolite compared with other treatments during overall period. In the finishing periods, ammonia gas emission was reduced (P<0.05) in 4% zeolite treatment more than that of the other treatments. Carcass weight and back fat thicknesses were not affected by zeolite treatments. But, the appearance of A grade pork was increased by the dietary supplementation of 4% zeolite. Feed cost was linearly decreased by increasing the supplementation of zeolite. According to this study, 4% supplement of zeolite is suitable for the improvement of carcass quality and feed conversion, the reduction of fecal ammonia gas emission and feed cost per body weight gain.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.3-13
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• 1985

The sorption behavior of some typical fission products such as Cs-137, long-lived radionuclide; Ce-144, rare-earth element; and Co-60, corrosion product on zeolite A, zeolite F-9 (faujasite) and amorphous zeolite was determined with the salt concentrations, 0.01 M- to 2.0 M- nitric acid and ammonium nitrate, and the shaking time, 15 minutes interval from 15 minute to 90 minute. Kd values were obtained through the batch experiment. In conclusion, the optimal conditions for isolation and removal of the typical radionuclides are as following: zeolite, amorphous zeolite; concentration, $0.01\;M-HNO_3\;and\;0.1\;M-NH_4NO_3$; pH4; shaking time, one hour; the most effective species, Cs-137.

• Membrane and Water Treatment
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• v.8 no.5
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• pp.437-448
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• 2017

A high quality Na-X zeolite membrane was synthesized on a seeded ${\alpha}-alumina$ disc by the secondary growth method. Structural characterization was done by X-ray spectroscopy, FT-IR spectroscopy, SEM and AFM imaging. The performance evaluation of the membrane was firstly tested in separation of glucose/water solutions by pervaporation process. There was obtained a separation factor $182.7{\pm}8.8$, while the flux through the membrane was $3.6{\pm}0.3kg\;m^{-2}\;h^{-1}$. The zeolite membrane was then used for desalination of aqueous solutions consisting of $Na^+$, $Ca^{2+}$, $Cs^+$ and $Sr^{2+}$ because of the importance of these ions in water and wastewater treatments. The effects of some parameters such as temperature and solution concentration on the desalination process were studied for investigating of diffusion/adsorption mechanism in membrane separation. Finally, high water fluxes ranged from 2 up to $9kg\;m^{-2}\;h^{-1}$ were obtained and the rejection factors were resulted more than 95% for $Na^+$ and $Ca^{2+}$ and near to 99% for $Cs^+$ and $Sr^{2+}$. Based on the results, fluxes were significantly improved due to convenient passage of water molecules from large pores of NaX, while the fouling was declining dramatically. Based on the results, NaX zeolite can efficiently use for the removal of different cations from wastewaters.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.552-557
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• 2010

This study was performed to investigate the effect of zeolite on the reduction of soil EC level in the plastic film house. The EC level of experimental soil was 5.0 dS $m^{-1}$ and the zeolite was applied to the soil at seven levels (0.5, 1, 2, 5, 10, 15, 20%) with three replications. The reduction degree of soil EC level showed positive tendency to the mixing ratio of zeolite. Especially, the EC level reduced rapidly from 5.01 to 2.8 dS $m^{-1}$ in the plot where zeolite was mixed by 20% 10 days after treatment. The pH level of soil was in positive relation to the mixing ratio of zeolite, contrary to the negative relation to the concentration level of water soluble Ca, Mg and phosphorus (P). The water contents of soil mixed with 15% and 20% zeolite were 14% and 17.3% respectively but it was 12.7% for control soil. Therefore, we expect natural zeolite to salts reduction agent for exchangeable cation and phosphate which is difficult to reduce by watering and other methods.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.726-732
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• 2016

In this study, we used activated carbon(AC) as a carbon source, along with zeolite, to prepare spherical carbons using sucrose, starch and phenolic resin(PR) as binder material. The physicochemical characteristics of the three samples(AZ4P, AZ6P and AZ8P) were examined by BET, XRD, SEM, EDX, $H_2S/NH_3$ gas adsorption, compressive strength and ignition test techniques. Through comparative analysis of the compressive strength and ignition test results the AZ8P sample was found to have the best hardness and the highest temperature resistance capacity. After activation, the AZ8P sample had the best $H_2S$ adsorption capacity, and AZ6P was the most suitable for the adsorption of ammonia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2028-2034
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• 2013

The effect of zeolite on the quality properties of fresh and broiled pork loin was investigated using 84 pigs that were fed with different feed ration of zeolite (0, 0.5, 1.0 and 2.0% zeolite) for 3 months. The pH of fresh pork loin fed with 0% and 2.0% zeolite was 5.95, which was higher than those of others (P<0.05). The cooking loss of fresh pork loin fed with 0.5% and 1.0% zeolite were 26.24% and 26.42%, respectively, which was higher than those of others (P<0.05). The dissolution crude lipid of 1.0% zeolite (3.11%) was highest, but that of 0% zeolite was lowest (P<0.05). L and a values were highest in fresh pork fed with 1.0% zeolite, however, b value was highest in fresh pork fed with 2.0% zeolite (P<0.05). In the results of L value of the broiled pork loin, the feed ration with 0% zeolite was highest (75.49) and decreased as the feed ration of zeolite increased (P<0.05). The a and b values were highest in broiled pork fed with 0.5% zeolite (P<0.05). The hardness, springiness, gumminess and chewiness of fresh and broiled pork loin fed with 2.0% zeolite were highest and increased as the feed ration of zeolite increased (P<0.05). In the result of sensory evaluation in broiled pork loin, color preference was increased as the feed ration of zeolite increased (P<0.05). Taste preference was highest in the 1.0% zeolite (10.70), followed by 2.0% (8.72), 0.5% (7.64), and 0% zeolite (6.44) (P<0.05). Flavor and appearance preferences were not significantly different between the groups. Texture preference was decreased as the feed ration of zeolite increased. The overall preference was highest in the 1.0% with zeolite (10.80), followed by 0.5% (10.04), 0% (8.41), and 2.0% (7.92) with zeolite (P<0.05). In conclusion, the optimal feed ration of zeolite for broiled pork loin was between 0.5 and 1.0% zeolite.