• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1180-1185
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• 2005

Iron sand, having iron as a major component, was applied in the treatment of synthetic wastewater containing Cu(II) or Pb(II). To investigate the stability of iron sand at acidic condition, dissolution of Fe and Al was studied with variation of solution pH ranging from 2 to 4.5. Iron concentration in the extracted solution was below the emission regulation of wastewater even at a strong acidic condition, pH 2. Although an important concentration of aluminum was extracted at pH 2, the dissolution greatly decreased above pH 3. This stability test suggests that application of iron sand has little problem in the treatment of wastewater above pH 3. Adsorption capacity of Cu(II) and Pb(II) onto iron sand was investigated in a batch and a column test. In case of Cu(II), rapid adsorption was noted, showing 50% removal within 2 hrs, and then reached a near complete equilibrium after 24 hrs. Adsorption was favorable at higher pH in each metal ion and showed a near complete removal above pH 6, indicating a typical cationic-type adsorption. From the adsorption isotherm obtained with variation of the concentration of each metal ion, the maximum adsorption capacity of Cu(II) and Pb(II) was identified as 2,170 mg/kg 및 3,450 mg/kg, respectively.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.613-617
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• 1997

This study was performed to investigate the effects of the type of utensils (onggi, aluminum, enamel coated, stainless-steel and stone), cooking sources (deionized-water, doenjang soup and kochujang soup), and cooking time (0, 10, 20, and 30 min) on aluminum leaching. Aluminum content leached by onggi, aluminum, enamel coated, stainless-steel and stone was $0.53{\sim}2.76,\;1.17{\sim}4.20,\;0.77{\sim}3.23,\;0.53{\sim}2.03,\;0.83{\sim}2.70$ ppm in deionized-water, respectively; $4.60{\sim}7.73,\;6.45{\sim}11.50,\;5.53{\sim}9.27,\;3.50{\sim}6.70,\;5.00{\sim}9.13$ ppm in doenjang soup, respectively; $5.18{\sim}9.70,\;6.30{\sim}11.23,\;4.73{\sim}8.63,\;3.23{\sim}6.50,\;4.50{\sim}9.25$ ppm in kochujang soup, respectively. The leached aluminum content was increased with the elapse of cooking time. Aluminum utensil showed the highest leached aluminum content among different types of utensils.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.713-717
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• 2012

Approximately forty proteins in egg white have been widely studied for their functional properties. To develop a procedure of separation for pure and non-altered proteins from egg white, purification study was conducted to isolate lysozyme, ovotransferrin, and ovalbumin. Ion exchange cartridge can selectively separate proteins from egg white, and reversed-phase HPLC (RP-HPLC) could identify separated proteins. Proteins in egg white were purified by HI trap ion exchange cartridge SP and Q with buffers pH 8.0 and 5.2. C18 column (Phenomenex, USA) was used for RP-HPLC analysis and isocratic mobile phase was used with acetonitrile (ACN)/distilled water (DW)/trifluoroacetic acid (TFA) in the ratio of 50/50/0.1. Comparing the retention times of standards in RP-HPLC experiments showed that ovotransferrin, ovalbumin, and lysozyme in egg white were eluted successively in the RP-HPLC column after the pretreatment in SP and Q ion exchange cartridges.

• Journal of the Korean Electrochemical Society
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• v.14 no.3
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• pp.131-137
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• 2011

A simple and rapid electrochemical method for the quantitative analysis of $Mn^{2+}$ ion is demonstrated with a view to examine the $Mn^{2+}$ dissolution behavior of $LiMn_2O_4$. The method described herein is based on the oxidation reaction of $Mn^{2+}$ to $Mn^{4+}(MnO_2)$ in aqueous buffer solution. Under the optimum condition (pH 8.9 0.04 M $NH_3-NH_4Cl$ buffer solution and glassy carbon working electrode), the linear range of $5{\mu}M-100{\mu}M$ (0.275-5.5 ppm) [$Mn^{2+}$] is obtained for the Linear sweep voltammetry(LSV) and $0.2{\mu}M-10{\mu}M$ (0.011-0.55 ppm) [$Mn^{2+}$] for the differential pulse voltammetry (DPV), respectively. It is also noted that the oxidation reaction of $Mn^{2+}$ ion is reduced with increasing amount of the electrolyte ($LiPF_6$, EC, EMC) added to the measuring solution, which is found to be mainly due to $LiPF_6$ and EC rather than EMC.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.564-567
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• 2004

FAs and BAs indicated different chemical compositions and physical properties. Leaching of Pb in FAl and Cu in FA2 were 33.2mg/L and 5.92mg/L, these were high concentration above 30 and 2 times respectively in compared to permit level. Leaching of Hg and Cr were about 1/2 of permit level. When diatom was complexly mixed with portland cement, the 28 days compressive strength of mortar with FA2 was similar with that of control mortar. Furtherfore, leaching of heavy metal ions like as Pb, Cu, Hg, Cr was highly reduced.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.43-47
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• 2003

산화환경에 노출된 폐광석에 포함되어 있는 황화광물은 산소와 물과의 화학반응을 통한 산화작용을 받게 되고 주변 환경에 유해한 금속원소의 용출이 발생될 것으로 예상된다. 그러나 용해된 금속이온은 침전(precipitation), 공침(coprecipitation), 흡착(adsorption)반응에 의해 수용액으로부터 제거되어 자연적으로 고정화될 수 있다. 이번 연구는 서보광산의 폐광석 내 용해된 중금속원소들의 이동을 제한하는 요인으로서 2차 산화광물의 침전 및 용해된 중금속 원소들의 흡착 가능성을 광물학적으로 연구하였다. (중략)

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.553-559
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• 1991

The elution characteristics of rare earth elements in $NH^{4+}$ form cation exchange resin had been investigated. Elution were performed varing the loading amount, column diameter, column length and eluent pH. Analysing the chemical species contained in each effluent, elution mechanisms of rare earth elements and the separation of rare earth elements in monazite could be understood. The resolution values of adjacent rare earth elements were improved increasing rare earths adsorption amount wfith the same column within it's exchange capacity. With $NH^{4+}$ resin form, column length does not affect on the resolution values and retention time of rare earth elements and the rare earth-EDTA complex were not adsorbed on $NH^{4+}$ resin form. pH of eluent affected on the reactivities between rare earth elements and EDTA. Decreasing eluent pH, resolution values of adjacent rare earth elements were increased while increasing elution time.

• Journal of Conservation Science
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• v.26 no.4
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• pp.397-406
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• 2010

The most ideal method to measure the water-soluble $Cl^-$ ion eluted from iron artifacts is conducting the analysis on desalting solution by Ion Chromatography. But most institutes related to cultural heritages use Cl meter by reason of lack of budget and experts. This study evaluated reliability and stability between Cl meter and Ion Chromatography by doing cross-validation with results from two methods to detect $Cl^-$ ion of desalting solution. From D.I water, extremely small quantities of $Cl^-$ ion was detected by the influence of remaining water-soluble $Cl^-$ ion at the electrode of Cl meter and water-soluble $Cl^-$ which remains in Sodium sesquicarbonate, components of reagent was detected as well. The first desalting solution had the most $Cl^-$ ions, $Cl^-$ ion slightly decreased from the second to the fourth desalting solution and tend to decrease again at the stage of dealkalified in D.I water. Each Cl meter has the standard deviation according to the measured numbers and the higher concentration of $Cl^-$ ion the desalting solution has, the wider the deviation is. But when the concentration of $Cl^-$ ion is low, it was stable to use Cl meter to detect the concentration of $Cl^-$ ion from iron artifacts because there is the small deviation, It is thought that conductivity meter method is not suitable for measuring $Cl^-$ ion, because the electrical conductivity of alkaline solution is too high to measure $Cl^-$ ion.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.266-271
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• 2004

지리적으로 이격된 마산과 서부산 지역의 불국사 화강암 분포지에서 정량적인 풍화도를 판별하기 위해 화학적 풍화지수와 등급을 산정하였다. 연구를 위해 채취된 시료에 대해 풍화 생성광물 동정, 전암분석, 산침수에 의한 이온용출 시험을 실시하였으며, 풍화지수와 지형적인 요소와 풍화속도를 고려하여 풍화등급들 산정하였다. 분석 결과 동일한 물리적, 광물학적 특성을 가지고 있으나 풍화에 따라 생성되는 점토광물의 종류와 함량에서 차이를 보여주며, 풍화의 진행 경로과 범위는 매우 상이한 결과를 보여 준다. 이러한 결과는 암석의 풍화가 모암의 조건 외에 지형, 지질구조, 기온, 강수량과 같은 환경적인 요소에 밀접하게 관련되어 있는 것을 의미할 뿐만 아니라 풍화도 산정에서 환경적인 요소에 대한 해석이 반드시 요구된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.132-136
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• 2003

폐광된 광산에 방치된 폐광석에 함유되어 있는 황화광물이 분해되어 다른 광물에 흡착되거나, 산화환경에 안정한 형태의 2차 광물로 침전 혹은 공침 되는가에 대한 연구는 광산복 원을 결정하는데 직접적인 지구화학적 자료로 활용될 수 있다. 따라서 이번 연구에서는 청양광산에 방치된 폐광석을 대상으로 XRD, SEM/EDS연구를 이용하여 산화작용으로 인한 황화광물 주변에 침전된 2차 광물에 대한 광물학적 연구를 수행하였다. 광물학적 연구 결과, 산화환경에서 황화광물의 산화작용으로 인하여 용출된 중금속 이온과 철과 망간 이온들은 침전(Fe, Mn, Pb), 공침 (Fe, Mn, As, Pb) 및 흡착(As, Cu, Pb, Zn) 등의 화학반응을 통하여 다시 고정화됨으로서, 현장에서 자연적으로 정화되고 있는 것이 확인되었다.