• Environmental Engineering Research
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• v.18 no.4
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• pp.267-276
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• 2013

This study presents a comparison of different protocols for the synthesis of iron-loaded zeolites, and the results of their application, as well as that of zeolite-A (Z-A), to the removal of ammonium and phosphate from aqueous media. Zeolites prepared by three methods were evaluated: iron-incorporated zeolites (IIZ), iron-exchanged zeolites (IEZ), and iron-calcined zeolites (ICZ). The optimal iron content for preparing of IIZ, as determined via scanning electron microscopy and X-ray photoelectron spectroscopy analyses, expressed as molar ratio of $SiO_2:Al_2O_3:Fe$, was below 0.05. Ammonia removal revealed that the iron-loaded zeolites have a higher removal capacity than that of Z-A due, not only to ion-exchange phenomena, but also via adsorption. Greater phosphate removal was achieved with IEZ than with ICZ; additionally, no sludge production was observed in this heterogeneous reaction, even though the coagulation process is generally accompanied by the production of a large amount of undesired chemical sludge. This study demonstrates that the developed synthetic iron-loaded zeolites can be applied as a heterogeneous nutrient-removal materials with no sludge production.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.380-387
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• 2018

Finding poly(amidoxime) (PAO) based adsorbent with better performance in U(VI) extraction from seawater is a hot research topic. By employing plasma treatment, the bi-functionalized adsorbents containing amidoxime and phosphate (labelled as $PO_4/PAO$) were successfully synthesized. The obtained $PO_4/PAO$ was characterized and applied for the potential extraction of U(VI) from aqueous solution. The results show that $-PO_4$ enhanced the hydrophilicity of PAO. $PO_4/PAO$ possesses good selective sorption ability for U(VI) and excellent reusability. The findings is helpful to understand optimizing performance of PAO based adsorbents for uranium extraction from seawater.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.725-730
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• 2005

In the development of biomaterials as a substitute of hard tissues, the biocompatibility and osteoconductivity of the biomaterial are considered to be one of the most significant considerations. These biological properties of a material can be greatly improved by the modification of the surface properties by the depositing calcium phosphate thin films on the material since calcium phosphate films possess similar chemical compositions to hard tissues. The success of a material as a biomaterial will be determined by the interaction of the surface of the material with the adhesion molecules which induce cellular adhesion and biological responses of the adherent cells. Depending on the adsorption mechanisms and adsorbed conformation of the adhesion molecules on the surface of the biomaterial, cellular responses, such as adhesion, proliferation and differentiation of osteoblast cells, can be promoted or restricted. It has been reported that materials of which surfaces were modified with thin films of calcium phosphate appeared to be more osteoconductive. Rapid formations of bone nodule in addition to higher differentiations of osteoblast have been observed on the calcium phosphate thin films.

• Korean Journal of Poultry Science
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• v.16 no.3
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• pp.157-167
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• 1989

Pretreatment of egg white and ion exchange resins was attempted to separate lysozyme from egg white efficiently. Apparent viscosity of egg white could be decreased to 3cp by homogenization for 30 minutes at 2, 000rpm and ultrasonication for 45 minutes. The result of testing adsorption capacity of lysozyme was as follows； CM-Sephadex C-25 ＞Duolite C464＞Amberlite C-50＞Dowex MSC-1＞Amberlite IRC-50＞Amberlite IRC-84. Although CM-Sephadex C-25 showed highest adsorption capacity of lysozyme, egg white could not eluted easily. Duolite Cf64 was selected based on relatively high lysozyme adsorption and good egg white eluting property for separation of egg white lysozyme. Na$^{＋}$ form of Duolite C-464 was most effective on adsorption of Iysozyme. To separate lysozyme from egg white efficiently rinse buffer and eluting solution were selected 0.1M sodium phosphate buffer at pH 6.5 and 10% ammonium sulfate respectively. After separating lysozyme from egg white, foaming power of egg white was decreased to 85.3%. Color of egg white gel was not changed while hardness of egg white gel was decreased by 30% after separating lysozyme. However, elasticity of egg white gel was increased by 13% in lysozyme-separated egg white.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.151-160
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• 2014

Capacitive deionization(CDI) has many advantages over other desalination technologies due to its low energy consumption, less environmental pollution and relative low fouling potential. The objectives of this study are evaluate the performance of CDI which can be used for dissolved salts removal from sewage. To identify ion selectivity of nitrate and phosphate in multiionic solutions and adsorption/desorption performance related to applied potential, a series of laboratory scale experiments were conducted using a CDI unit cell with activated carbon electrodes. The CDI process was able to achieve more than 75 % TDS and $NO_3{^-}$, $NH_4{^+}$ removals, while phosphate removal was 60.8 % and is inversely related in initial TDS and $HCO_3{^-}$ concentration. In continuous operation, increasing the inner cell pressure and reduction of TDS removal ability were investigated which are caused by inorganic scaling and biofouling. However a relative mild cleaning solution(5 % of citric acid for calcium scaling and 500 mg/L of NaOCl for organic fouling) restored the electrochemical adsorption capacity of the CDI unit to its initial level.

• Applied Biological Chemistry
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• v.2
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• pp.45-52
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• 1961

The decomposition of malathion in dust for mulations prepared from four Korean tales as carriers during storage period has been studied. Amberlite CG-120, a cation exchange resin . which has higher cation exchange capacity than tales, was also used as a carrier in hope of finding out the effect of nagative charge upon the decomposition of malathion. Besides the original talc powders obtained directly from the mines, the hydrogen ion saturated forms were also used as carriers for comparisonal study. The saturated ions for the resin were hydrogen, sodium and magnesium. As the physical properties of the tales, colloid content, water adsorption capacity, PH, specific surface, phosphate fixing capacity and exchangeable canons were determined, and these properties were correlated with the amount of the decomposition. Following results were obtained from the experiment. 1. The malathion in the talc in dust was found to decompose around 10-15% ofthe total withina month. About 50% of the decom position that took place after a month was found to occur within a week. 2. The resin which has higher cation exchange capacity than the tales was highly effective in the decomposition of malathion compared with the tales. 3. In every case the saturation of the exchange complexes with hydrogen ion greatly accelerated the decomposition of malathion. 4. The most highly correlated physical properties with the decomposition were colloid content and specific surface of the tales. 5. The water adsorption and phosphate fixing capacities of the tales were found not to correlate with the amount of malathion decomposed. From the experimental results it was concluded that the active negative spots on the colloidal tales or the resin attract the electropositive phosphorus atom in a malathion molecule thereby inducing the decomposition easier. The presence of hydrogen ion nearby might cause a catalytic effect in the decomposition of malathion.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.543-550
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• 2016

Amine-type PP-g-VBC-EDA adsorbent, which possesses anionic exchangeable function, was prepared through photoinduced graft polymerization of vinylbenzyl chloride (VBC) onto polypropylene non-woven fabric and subsequent amination reaction using ethylenediamine (EDA). Adsorption characteristics of anionic nutrients on the PP-g-VBC-EDA adsorbent have been studied by batch adsorption experiments. The equilibrium data well fitted the Langmuir isotherm model, and the maximum monolayer sorption capacity was found to be 59.9 mg/g for $NO_3-N$ and 111.4 mg/g for $PO_4-P$. The adsorption energies were higher than 8 kJ/mol indicating anion-exchange process as the primary adsorption mechanism. The pseudo-second order kinetic model described well the kinetic data and resulted in the activation energy of 9.8-36.7 kJ/mol suggesting that the overall rates of $NO_3-N$ and $PO_4-P$ adsorption are controlled by the chemical process. Thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ indicated that the adsorption nature of PP-g-VBC-EDA for anionic nutrients is spontaneous and exothermic. The PP-g-VBC-EDA could be regenerated by washing with 0.1 N HCl.

• Economic and Environmental Geology
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• v.31 no.4
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• pp.291-296
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• 1998

Pedogenic hematite is a well known agent for sink of pollutants and nutrients and for aggregation of particles in soils. Changes in physical and chemical properties of two sandy loam soils (Anahuac and Crowley soils) from the Southern Coastal Plain, the United States of America, were tested after adding finely ground crystalline hematite prepared for drilling fluid weighting material. There was an increase in hydraulic conductivity (HC) of the soils with addition of up to 3% by weight of hematite but a decrease in HC with addition of more hematite. The aggregate stability (AS) of the soils was not affected by adding hematite. Anahuac soil with higher content of organic matter and lower sodium adsorption ratio (SAR) had higher values of HC and AS than Crowley soil. Adding hematite also resulted in a slight increase in zinc (Zn) adsorption by the soils, but had no influence on the adsorption of phosphate.

• Clean Technology
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• v.16 no.4
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• pp.258-264
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• 2010

This study estimated the possibility of phosphate removal characteristics to utilize EAF(electric arc furnace) slag as submarine cover material. The major phosphate removal mechanism was a certain formation of HAP precipitation occurred by the ionization reaction between $Ca^{2+}$ and $OH^-$, which were leached from the EAF Slag. Another phosphate removal mechanism was the adsortion of EAF slag surface. As a result of $PO_4{^-}-P$ removal characteristics using continuous column reactor, $PO_4{^-}-P$ concentration decreased rapidly after 3 days and 10 days later, it show under 0.5 ppm. The result as applied in real sea water, shows that the phosphate removal effects were 93~98% by the subaqueous sediment removal using the EAF slag. In conclusion, EAF slag is useful in $PO_4{^-}-P$ removal and control and it is possible to use without additional process like crush and selection.

• Clinical and Experimental Vaccine Research
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• v.12 no.3
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• pp.232-239
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• 2023

Purpose: The purpose of this study was to compare the antigenic potency and stability of tetanus and diphtheria (Td) vaccines when combined with aluminum phosphate (AlPO₄) and liposome adjuvants. Materials and Methods: In vitro and in vivo analyses were conducted using the single radial immunodiffusion method and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Td vaccines were prepared with AlPO₄ adsorption and liposome-mediated delivery, and protein antigens were characterized using these methods. Results: The results revealed that the liposome-mediated Td vaccines exhibited higher immunogenicity compared to the AlPO₄-adsorbed Td vaccines. Additionally, the liposome-mediated Td vaccines demonstrated higher stability as native antigens. Conclusion: This study highlights the importance of utilizing liposome adjuvants in vaccine development. The liposome-mediated Td vaccines showed enhanced immunogenicity and stability, making them a promising approach for improving vaccine efficacy. Understanding and optimizing adjuvant strategies can contribute to the development of effective vaccines against various diseases.