• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.251-257
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• 2011

The processes for the preparation of ZnO powder by using EAF(electric arc furnace)dust was studied by wetting method which are divided to two steps, carried out of the elution processes by various concentrations of sulfuric acid is reacted with EAF dust as the former, and the latter were performed by a number of specified processes, which are leaching process depends on various pH, cementation, ozone and heat treatment processes etc. Experimental results showed that the appropriate pH range is pH7.5~8.0 and the resulting zinc content is range of 37~38%, the residual quantities of the heavy metals are less than 3ppm individually by cementation process except Mn, even though the Mn metal could not be removed by cementation process but was removed up to 0.2ppm by the ozone process from 70ppm initially. Finally, 80.2% of ZnO was obtained by the heat treatment at $500^{\circ}C$.

• Analytical Science and Technology
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• v.28 no.6
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• pp.370-376
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• 2015

An analytical method for determining phenol considered priority pollutants of the US EPA and precursor of toxic phenolic compounds by solid-phase extraction (SPE) and high performance liquid chromatographic systems (HPLC) equipped with fluorescence and mass selective detectors have been developed. The SPE process for sample preconcentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of pH, elution solvent, and elution volume on the recoveries of the analytes were investigated with HPLC/FLD. Average recovery of >87.0% was achieved with 60 mg sorbents using 5 mL of methanol as an elution solvent at pH=3.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1527-1532
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• 2007

Lysine produced during microbial fermentation is usually recovered by an ion-exchange process, in which lysine is first converted to the cationic form (by lowering the pH to less than 2.0 with sulfuric acid) and then fed to a cationexchange column containing an exchanger that has a sulfone group with a weak counterion such as NH;. Ammonia water with a pH above 11 is then supplied to the column to displace the purified lysine from the column and allow its recovery. To enhance the adsorption capacity and for a possible reduction in chemical consumption, monovalent lysine fed at pH 4 was investigated in comparison with conventional divalent lysine fed at pH 1.5. The adsorption capacity increased by more than 70% on a mass basis using pH 4 feeding compared with pH 1.5 feeding. Lysine adsorbed at pH 4 started to elute earlier than that adsorbed at pH 1.5 when ammonia water was used as the eluant solution, and the extent of early elution became more notable at lower concentrations of ammonia. Moreover, the elution of monovalent lysine fed at pH 4 displayed a stiffer front boundary and higher peak concentration. However, when the ammonium concentration was greater than 2.0 N, complete saturation of the bed was delayed during adsorption and the percent recovery yield from elution was lowered., both drawbacks that were considered inevitable features originating from the increased adsorption of monovalent lysine.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.557-564
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• 2009

The objective of this study is to efficiently recover phosphorus contained in sewage sludge by a struvite-forming method. The performances were evaluated under various operating conditions(elution with the kind of acid, Mg-compound and temperature) in order to reach the optimum conditions of struvite-forming. As a result, as an elution solution, the elution efficiency of $H_2SO_4$ was 2.65 times higher than that of HCl. Also, the precipitation efficiency of struvite was the highest (97.4%) in case of using $MgCl_2{\cdot}6H_2O$ as Mg-compounds at $25^{\circ}C$. However, the side reaction by Fe, Al and Zn appeared in process of phosphorus recovery. To solve some problems caused by side reacton, large quantities of co-precipitation materials produced by side reaction were removed by precipitating phosphorus compounds in pH 7. Consequently, the recovery efficiency of phosphorus by a struviteforming method was 82.99%, and purity of the recovered struvite product was high.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.196-203
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• 2002

A novel process for urokinase purification was studied using p-aminobenzamidine as the ligand and sepharose 4B as the matrix. The adsorption, washing, and elution conditions were optimized by an unusual method. An adsorption buffer containing 2.5 M NaCl and $1\%$ Tween 80 facilitated the adsorption of urokinase on the affinity media and prevented contaminants from binding to the p-aminobenzamidine affinity gel. It was found that $5\%$ Tween 80 removed most of the contaminants from the affinity column. A 0.2 M glycine elution buffer containing 0.5 M NaCl (pH 3.0) was found to have a strong elution ability with a high recovery and purity of urokinase. A crude urokinase material of231 IU/mg protein from human urine was purified to 124,300 IU/mg protein with a purification factor of 538 and yield of $86.7\%$. As a result, a high purity urokinase was obtained with only a single affinity chromatography step. The purification process was successfully scaled-up to a 2-1 chromatography column. The resulting urokinase eluate could be directly lyophilized, thereby complying with Chinese pharmacopoeia (1995 version) standards.

• Journal of Radiation Protection and Research
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• v.45 no.4
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• pp.154-162
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• 2020

Background: Several studies have reported that wild mushrooms contain high amounts of radioactive cesium (137Cs). After the Fukushima Daiichi Nuclear Power Plant Accident, a significantly high concentration of 137Cs has been detected in wild mushrooms, and their consumption may be the cause of the chronic internal exposure of local consumers to radioactivity. Therefore, an accurate evaluation of the internal radioactivity resulting from mushroom ingestion is needed. Materials and Methods: The 137Cs elution rate through the cooking and digestion stages was evaluated using in vitro experiments. The edible mushroom Pleurotus djamor was taken as a sample for the experiments. The mushrooms were cultivated onto solid media containing 137Cs. We evaluated the internal dose based on the actual conditions using the elution rate data. For various cooking methods, the results were compared with those of other wild edible mushrooms. Results and Discussion: From the elution experiment through cooking, we proved that 25%-55% of the 137Cs in the mushrooms was released during soaking, boiling, or frying. The results of a simulated digestion experiment after cooking revealed that almost all the 137Cs in the ingested mushrooms eluted in the digestive juice, regardless of the cooking method. The committed effective dose was reduced by 20%-75% when considering the dissolution through the cooking process. Conclusion: We found that cooking lowers 137Cs concentration in mushrooms, therefore reducing the amount of radioactivity intake. Besides, since there were differences between mushroom types, we demonstrated that the internal exposure dose should be evaluated in detail considering the release of 137Cs during the cooking stages.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.436-437
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• 2018

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.422-423
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• 2000

The protozoan parasite Giardia lamblia has been implicated as the causative agents of many outbreaks of waterborne intestinal illness. Accurate evaluation of Giardia lamblia removal in water treatment process requires a reliable method for measuring the concentrations of these pathogens in water. The relative recovery of Giardia cysts was assessed for seeded samples of distilled water. Cysts preparation was done by encystment in vitro. Membrane filtration was evaulated with cellulose acetate, polycarbonate, polypropylene, polyethersulfone, nylon membranes. Elution conditions were varied to improve cyst recovery.

• Journal of Fashion Business
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• v.9 no.3
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• pp.99-113
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• 2005

Recently, problems related to the natural dyeing have been addressed. Severer problems have been posed by the elution at metallic ions and dyestuff tram dyed fabrics. In order to prevent the elution tram the dyed fabrics, it is needed to improve the fastness. Especially, it is the most important measure to improve the fastness to perspiration in terms at human body safety. In this study, we employed chitosan pretreatment method bet ore the dyeing process, anticipating that the pretreatment might improve the fastness. We used Al, Sn, and Cu as mordants and investigated the fastness to light and perspiration of the chitosan treated and dyed fabric specimens. By the chitosan pretreatment, the fastness to perspiration improved, while the fastness to light did not.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.9.1-9.5
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• 2024

Method development for complex low molecular mass (LMM) samples using reversed-phase (RP) separation conditions presents significant challenges due to the presence of many unknown analytes over wide concentration ranges. This guide aims to optimize method parameters-column length (L), temperature (T), flow rate (F), and final mobile phase conditions (Øfinal)-to maximize separation peak capacity. Validated by prior research, this protocol benefits laboratories dealing with metabolomics, natural products, and contaminant screening. This practical guide provides a structured approach to maximizing peak capacity for complex LMM separations. It complements computational optimization strategies and offers a step-by-step method development process. The Snyder-Dolan test is highlighted as essential for determining the need for gradient or isocratic elution and guiding column length decisions. The decision tree framework helps analysts prioritize variable optimization to develop effective separation methods for complex samples.