• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.168-172
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• 2001

실제로 폐수 등에는 중금속 이온이 단일이온으로 존재하기보다는 여러 중금속으로 존재하여 있는 것이 대부분이다. 이런 혼합 중금속의 이온들은 모두 경쟁적인 관계에 있으면서 각각의 중금속이온의 제거능은 떨어지지만 전체적인 중금속 제거량은 비슷한 것으로 나타났다.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.238-246
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• 2005

We conducted this investigation to observe competitive adsorption phenomena among the heavy metals onto the available sorption sites of soil particle surfaces in sandy clay loam and clay soil collected from Nonsan city, Chungnam and Yoosung, Daejeon in Korea, respectively. Polluted and contaminated soils can often contain more than one heavy metal species, resulting in competition for available sorption sites among heavy metals in soils due to complex competitive ion exchange and specific sorption mechanism. And the adsorption characteristics of the heavy metals were reported that the selectivity for the sorption sites was closely related with electropotential and electro negativity carried by the heavy metals. The heavy metals were treated as single, binary and ternary systems as bulk solution phase. Adsorption in multi-element system was different from single-element system as Cr, Pb and Cd. The adsorption isotherms showed the adsorption was increased with increasing equilibrium concentrations. For binary and ternary systems, the amount of adsorption at the same equilibrium concentration was influenced by the concentration of individual ionic species and valence carried by the respective heavy metal. Also we found that the adsorption isotherms of Cd and Pb selected in this experiment were closely related with electronegativity and ionic potential regardless number of heavy metals in solution, while the adsorption of Cr carried higher valance and lower electro negativity than Cd and Pb was higher than those of Cd and Pb, indicating that adsorption of Cr was influenced by ionic potential than by electronegativity. Therefore adsorption in multi-element system could be influenced by electronegativity and ionic potential and valance for the same valance metals and different valance, respectively. But it still needs further investigation with respect to ionic strength and activity in multi-element system to verify sorption characteristics and reaction processes of Cr, especially for ternary system in soils.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.74-78
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• 2003

To determine the urease inhibitory activity of various heavy metal ions, a photometric cuvette assay for measuring ammonia production was developed. In this assay, the absorbance values at 630 m were linearly increased according to the ammonia concentrations up to 3.0 mg/l (r : 0.998). The urease inhibitions upon addition of a single species of heavy metal ions were in the decreasing order of Hg(II) > Pb(II) > Cu(II) > Cd(II) > Zn(II) ions. As expected, the urease inhibitions at a fixed concentration of a single species and at varying concentrations of other species occurred in the additive way. The above results show the applicability of the current method to the selective detection on Hg(II) ions as well as the screening of heavy metal ions possibly present at various samples.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.159-164
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• 2021

Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.84-85
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• 1994

본 연구는 수용상에 포함된 중금속이온중 에멀젼 액막법(Emulsion Liquid Membranes, ELM)을 이용하여 납이온을 제거시키기 위한 연구이다. 지금까지 수용액상의 중금속 이온의 제거는 전통적으로 이온 침전법을 사용하여 왔다. 그러나 이 방법은 스럿지 처리문제가 남아 있고 식수로 이용되는 수처리에는 식수기준 만족도 때문데 적합하지 않았다. ELM법에 의한 금속이온 제거처리는 전기도금에 의하여 중금속이온을 회수할 수 있고 고도의 수처리를 가능케하여 최근 많은 관심을 갖고 있다. 본 연구에서는 납 이온 추출제로서 D2EPHA와 Alamine336의 이온교환제를 사용하여, 이 씨스테므이 추출 평형자료를 구하고 pH, 추출제의 농도, 교반속도, 에멀젼비율등에 의한 추출효과등을 검토하였다. 또한 2단계 추출 방법을 사용하여 금속이온추출에서 가장 큰 문제점인 유기상 용액의 leakage를 해결하고자 하였다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.315-318
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• 2003

본 연구에서는 NaCl 용응법에 의해 fly ash로부터 합성된 swelling mica의 다양한 이온의 교환특성과 이온교환이 결정구조에 미치는 영향을 규명함으로서 swelling mica에 의한 유해 방사능 물질 및 중금속의 효과적인 제거제로서의 활용 가능성을 조사하고자 하였다. 1가 양이온이 흡착된 FA-swelling mica의 $d_{001}$/ peak의 강도는 흡착된 이온의 직경이 클수록 감소하는 경향을 나타내었으나, $d_{001}$/ value는 흡착된 이온의 직경과 뚜렷한 상관관계가 없었다. 또한 FA-swelling mica의 NH4 이온의 흡착량은 133 $cmol^{+}$/kg, K 이온은 127 $cmol^{+}$/kg, Li 이온은 23 $cmol^{+}$/kg으로서 방사성 물질과 중금속 이온에 비해 낮은 경향을 나타내었다. 2가 양이온이 흡착된 FA-swelling mica의 $d_{001}$/ peak 강도와 $d_{001}$/ value는 이온의 직경에 관계없이 비슷한 값을 나타내었으며 1가 양이온의 흡착에 비해 구조적 안정성이 높았다. Sr 및 Ba 이온의 흡착반응은 느리고 지속적으로 일어났으며 Ca와 Mg 같은 2가 양이온에 비해 선택성이 훨씬 높은 것으로 나타났다. 또한 Sr 및 Ba 이온과 같이 직경이 큰 방사성 원소들은 swelling mica의 층간에 흡착되어 결정구조가 부분적으로 붕괴됨으로서 이온을 비가역적으로 고정하는 특성을 나타내었다. Zn, Cu, Cd 및 Pb 등의 중금속 이온이 흡착된 FA-swelling mica의 $d_{001}$/ value는 12.70~12.80$\AA$으로서 매우 일정하였으며, 이온 흡착에 의한 층간 팽창정도는 이온의 크기뿐만 아니라 수화정도에 따라 상이하였다. FA-swelling mica의 중금속 이온의 흡착은 층간 붕괴에 의해 일어나는 것으로 판단되며, 선택성과 흡착능력은 층간 붕괴속도와 비례하는 경향을 나타내었다. 또한 FA-swelling mica의 중금속 이온의 선택성은 Pb>Cu>Cd$\geq$Zn 순으로 나타났다.

• Journal of the Korea Convergence Society
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• v.7 no.1
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• pp.155-160
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• 2016

The convergence process utilized both leaching and ion exchange techniques has been investigated for the heavy metals removal in the abandoned mine of Chungyang Province, Korea. The contaminated soil samples by heavy metals from Samkwang mine were analysed by statistical analyses. The highly contaminated soils was initially separated by the flotation process. The selectivity indices were increased with increasing flotation reagents. The selectivity of separation was then improved by the use of both leaching and ion exchange processes in order to extract the heavy metals. The results of this study showed that the higher the sulfuric acid concentration, the leaching rate of heavy metals was increased. The lecheate then was removed by the ion exchange method. The anticipating results might imply that convergence process utilized both leaching and ion exchange techniques would somehow apply for the removal of heavy metals in the abandoned mine.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.21-28
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• 2006

We investigated the mobilization of Cd, Pb, and Cr in two different soils in response to sorption capacities and competition for available sorption site while they moved under saturated water conditions. Two soil samples that were clay and sandy clay loam were collected within 20 cm from the upland surface. To do this, we used three different systems of heavy metal combinations such as single, binary, and ternary as solution phase. And then we observed the breakthrough curve (BTC) and elution as a function of pore volume by applying heavy metal solution and displacing K solution until these curves reached to maximum and minimum. The results showed that BTC and elution curves were not symmetric and it required more pore volumes with increasing species of heavy metals in solution phase, as well as longer tailings. Compared the areas over and under BTC and elution curve, relatively small amount of heavy metal was displaced by K even though there were differences in electronegativity among heavy metals. Conclusively, we assumed that heavy metals transport in soil could be influenced by soil physical nonequilibrium and chemical equilibrium in solution as far as there were more than two species of heavy metals existed.

• KSBB Journal
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• v.16 no.6
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• pp.609-613
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• 2001

New protein-based biosensors using fluorescence for the detection heavy metal ions were developed. The detection range of heavy metal ions was between 10$\^$-3/ mM - 1 mM using casein and albumin as a transducer of biosensor, respectively. Casein showed better results for detecting heavy metal ions than albumin. Simple assay method was developed for the selective analysis of the two heavy metal ions by the fluorescence at wavelength of excitation and emission. This method was successfully applied to determining the concentrations Of Co$\^$2+/ and Fe$\^$3+/.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.134-139
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• 2000

Crab shell의 중금속 제거 가능성과 그 효율을 검토하기 위하여 chemical sorbent인 cation exchange resin(CER), zeolite, granular activated carbon(GAC), powdered activated carbon(PAC)의 중금속 제거능을 비교한 결과 다음과 같은 결론을 도출할 수 있었다. 1) 0.1 mM～l.0 mM의 초기 중금속 농도에서 중금속 제거량에 미치는 영향을 비교해 보았을 때 중금속 제거의 평형에 도달하는 시간은 농도가 높을수록 오래 걸렸으며 단위 흡착제 질량당 중금속 제거량은 초기 중금속 농도가 높을수록 증가하였다. 특히 구리 이온 제거 실험에서는 낮은 농도에서 crab shell의 구리 이온 제거량이 CER의 경우보다 조금 떨어지는 경향을 보였으나, 대부분의 중금속 제거에 있어서는 crab shell이 다른 chemical sorbent에 비해 뛰어난 중금속 제거능력을 보였다. 2) 흡착 등온 모델에 적용해 보았을 때, 단위 흡착제 질량당 중금속 최대 흡착량이 crab shell > CER > zeolite > PAC =GAC의 순으로, 모든 중금속 제거 실험에서 crab shell이 가장 뛰어난 것으로 나타났다. 실제 폐수처리 공정에서는 GAC나 PAC가 많이 이용되고 있는데, 수중의 중금속을 보다 효율적이고 경제적으로 처리할 수 있는 crab shell을 폐수처리 공정에 응용할 수 있는 방안을 검토할 필요성이 있을 것으로 판단된다.