• 대한환경공학회지
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• 제28권6호
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• pp.640-647
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• 2006

도금공장에서 발생하는 폐수에는 니켈 등 중금속이 고농도로 함유되어 있어 그 처리가 매우 어려운 편이며, 최근에는 공해물질의 발생을 사전에 예방하는 공정을 도입하거나, 발생된 폐수 및 폐기물을 적절히 처리하여 재활용하는 청정기술이 도입되는 추세이다. 본 연구에서는 니켈 도금 공정에서 발생되는 폐수를 대상으로 이온교환과 전기투석 공정을 이용하여 니켈의 회수가능성 및 효율을 평가하였다. 이온교환수지 5 종을 이용한 이온교환 실험결과 S 1467(gel-type 강산성 양이온 교환수지)의 교환용량이 가장 높았으며 재생실험결과 4 N HCl을 재생재로 사용한 경우에서 재생율 및 재생농도가 가장 높았다. 전류밀도, 전극액 농도, 농축액 및 전극액 유량을 변화시켜가며 운전한 전기투석 실험결과 최적의 운전조건은 전류밀도 $250A/m^2$, 전극액 농도 2 N $H_2SO_4$, 전극액 및 농축액 유량 30 mL/min였다. 이온교환수지 500 mL를 사용한 이온교환 scale-up 실험결과 S 1467 수지의 교환용량은 1.88 eq/L resin, 재생율은 93.7% 이었고 cell pair 수를 2개로 증가시킨 전기투석의 scale-up 실험결과, 농축 및 희석효율은 증가하였으나, 전류효율은 일정하였다.

• 공업화학
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• 제7권2호
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• pp.321-325
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• 1996

$Cu^{n+}$ 교환된 Y형 제올라이트 상에서 진행되는 NO분해반응의 특성을 양자화학적 계산을 통해 해석하였다. 제올라이트내 양이온 자리를 나타내는 Cluster모델들에 대해 CNDO/2와 같은 이론적 계산을 수행하여 전체에너지, LUMO에너지 및 Wiberg결합차수값들을 얻었다. 각 모델들의 전체에너지와 결합차수값들을 통해 제올라이트 골격내 $Cu^{n+}$ 양이온 자리에서의 NO분해반응에 대한 반응기구를 고찰하였다. 제안된 분자모델들은 각기 다른 Si/Al비와 $Cu^+$ 및 $Cu^{2+}$ 교환된 양이온의 경우로 구분하여 고찰하였다. LUMO에너지의 계산을 통해 모델분자들의 L산성도를 해석하였다. NO분해반응의 메카니즘은 NO의 흡착, $N_2$ 및 $O_2$로의 분해, $N_2$ 및 $O_2$의 탈착의 단계가 연속적으로 진행될 가능성이 있었다. 양이온 자리에서 $Cu^{2+}$는 $Cu^+$ 보다 더 강한 L산성을 나타내었다.

• 한국산업보건학회지
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• 제6권1호
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• pp.138-143
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• 1996

After oral administration of 14C-labelled $N^G$-mono[methyl-14C]-L-arginine into rats, 38.2 % and 14.7 % of the administered radioactivity bad been recovered in the urine and stool during 10 days. In the urine, 59.4 % of the radioactivity was recovered in the first 24-hours and used for the indentification of the formation of methylamine. The strong cation-exchange resin column chromatography showed 6.3 %, 7.4 %, 4.9 %, and 81.5 % of the distributions of radioactivity of the neutral, monomethylamine, basic, and uneluted portions, respectively. The radioactivity of monomethylamine portion reeluted into the column chromatography was 39.5 %. The radioactivities corresponding monomethylamine in the column chromatography, thin-layer chromatography, and thin-layer electrophoresis were 39.5 %, 37.3 %, and 28.8 % of the recovered radioactivity, respectively.

• KSBB Journal
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• 제30권3호
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• pp.114-118
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• 2015

In this study, we have developed a microbe-carrier that combined Desulfovibrio desulfuricans and zeolite for removal of Zn and As in contaminated seawater. Desulfovibrio desulfuricans, one of the sulfate-reducing bacteria (SRB) microorganism was exhibited stable growth characteristics in highly salted water and strong resistance to Zn and As contaminated seawater. Moreover, zeolites are one of the most useful carrier to remove heavy metals from wastewaters. The results showed that SRB immobilized zeolite carrier can enhance removal ratio of Zn and As. In addition, heavy metals tended to be better removed in medium at conditions of $37^{\circ}C$. In case of heavy metal concentration, they were effectively removed ranging from 50 to 100 ppm. These results show that SRB-zeolite carriers hold great potential to remove cationic heavy metal species from industrial wastewater in marine environment.

• Mycobiology
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• 제41권3호
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• pp.149-154
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• 2013

An ${\alpha}$-glucosidase inhibitor was developed from Aspergillus oryzae N159-1, which was screened from traditional fermented Korean foods. The intracellular concentration of the inhibitor reached its highest level when the fungus was cultured in tryptic soy broth medium at $27^{\circ}C$ for five days. The inhibitor was purified using a series of purification steps involving ultrafiltration, Sephadex G-25 gel permeation chromatography, strong cation exchange solid phase extraction, reverse-phase high performance liquid chromatography, and size exclusion chromatography. The final yield of the purification was 1.9%. Results of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis indicated that the purified ${\alpha}$-glucosidase inhibitor was a tri-peptide, Pro-Phe-Pro, with the molecular weight of 360.1 Da. The IC50 value of the peptide against ${\alpha}$-glucosidase activity was 3.1 mg/mL. Using Lineweaver-Burk plot analysis, the inhibition pattern indicated that the inhibitor acts as a mixed type inhibitor.

• 약학회지
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• 제54권5호
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• pp.377-386
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• 2010

Single-dimensional (1-D) and two-dimensional (2-D) LC methods were utilized to separate peptides from various sources followed by MS/MS analysis. Two-dimensional ultra-high performance liquid chromatography is a useful tool for proteome analysis, providing a greater peak capacity than 1-D LC. The most popular 2-D LC approach used today for proteomic research combines strong cation exchange and reversed-phase LC. We have evaluated an alternative mode for 2-D LC of peptides using 2-D RP-RP nano UPLC Q-TOF Mass Spectrometry, employing reversed-phase columns in both separation dimensions. As control experiments, we identified 129 proteins in 1-D LC and 322 proteins in 2-D LC from E. coli extract peptides. Furthermore, we applied this method to rat primary hepatocyte and a total of 170 proteins were identified from 1-D LC, and 527 proteins were identified from all 2-D LC system. The in-depth protein profiling established by this 2-D LC MS/MS from rat primary hepatocyte could be a very useful reference for future applications in regards to drug induced liver toxicity.

• 방사성폐기물학회지
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• 제19권1호
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• pp.1-7
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• 2021

The pH dependence of sorption distribution coefficient (Kd) of Np(IV) on MX-80 in Ca-Na-Cl type solution with the ionic strength of 0.3 M, which was similar to one of the reference groundwaters in crystalline rock, was experimentally investigated under the reducing conditions. The overall trend of Kd on MX-80 was independent of pH at 5 ≤ pH ≤ 10 but increased as pH increased at pH ≤ 5. The 2-site protolysis non-electrostatic surface complexation and cation exchange model was applied to the experimentally measured pH dependence of Kd and the optimized surface complexation constants of Np(IV) sorption on MX-80 were estimated. The values of surface complexation constants in this work agreed relatively well with those in the Na-Ca-Cl solution previously evaluated, suggesting that compared to Na+, the competition of Ca2+ with Np(IV) for surface complexation on MX-80 was not much strong in Ca-Na-Cl solution. The sorption model well predicted the pH dependence of Kd values but slightly overestimated the sorption at the low pH region.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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• pp.43-49
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• 1998

Retardation effect of heavy metals in soils caused by adsorption onto the surfaces of solids particles is well known phenomena. The adsorption of metal ions has been recognized more strong in clay mineral and organic matter contents rather than sands and gravels. In this study, we investigated the retardation effect in two sandy soils by conducting batch and column tests. The column tests were conducted to obtain the relationship between concentration and time known as breakthrough curve (BTC). We applied pulse type injection of ZnCl$_2$solution on the inlet boundary and monitored the effluent concentration at the exit boundary under steady state condition using EC-meter and ICP-AES. Batch test consisted of an equilibrium procedure for fine fractions collected from two sandy soils for various initial ZnCl$_2$concentrations, and analysis of Zn ions in equilibrated solution using ICP-AES. The results of column test showed that i) the peak concentration of Zn analyzed by ICP was far less than that detected by EC-meter for both soils and ii) travel times for peak concentration were more less identical for two different monitoring techniques. The first result can be explained by ion exchange between Zn and other cations initially present in the soil particles since ICP analysis showed a significant amount of Ca, Mg ions in the effluent. From the second result, we found that retardation effect was not present in these soils due to strong cation exchange capacity of Zn ion over other cations since we did not apply a solution containing more adsorptive cations such as Al. The result of batch test also showed high distribution coefficients (K$_{d}$) for two soils supporting the dominant ion exchange phenomena. Based on the retardation factor obtained from the Kd, we predicted the BTC using CDE model and compared with the BTC of Zn concentration obtained from ICP The predicted BTC, however, disagreed with the monitored in terms of travel time and magnitude of the peak concentrations. The only way to describe the prominent decrease of Zn ion was to introduce decay or sink coefficient in the CDE model to account for irreversible decrease of Zn ions in liquid phase.e.

• 한국환경과학회지
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• 제18권6호
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• pp.645-654
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• 2009

Lab-scale Electrodialysis(ED) system with different membranes combined with before or after pyroma process were carried out to remove nitrate from two pickling acid wastewater containing high concentrations of $NO_3\;^-$(${\approx}$150,000 mg/L) and F($({\approx}$ 160,000 mg/L) and some heavy metals(Fe, Ti, and Cr). The ED system before Pyroma process(Sample A) was not successful in $NO_3\;^-$ removal due to cation membrane fouling by the heavy metals, whereas, in the ED system after Pyroma process(Sample B), about 98% of nitrate was removed because of relatively low $NO_3\;^-$ concentration (about 30,000 mg/L) and no heavy metals. Mono-selective membranes(CIMS/ACS) in ED system have no selectivity for nitrate compared to divalent-selective membranes(CMX/AMX). The operation time for nitrate removal time decreased with increasing the applied voltage from 10V to 15V with no difference in the nitrate removal rate between both voltages. Nitrate adsorption of a strong-base anion exchange resin of $Cl\;^-$ type was also conducted. The Freundlich model($R^2$ > 0.996) was fitted better than Langmuir mode($R^2$ > 0.984) to the adsorption data. The maximum adsorption capacity ($Q^0$) was 492 mg/g for Sample A and 111 mg/g for Sample B due to the difference in initial nitrate concentrations between the two wastewater samples. In the regeneration of ion exchange resins, the nitrate removal rate in the pickling acid wastewater decreased as the adsorption step was repeated because certain amount of adsorbed $NO_3\;^-$ remained in the resins in spite of several desorption steps for regeneration. In conclusion, the optimum system configuration to treat pickling acid wastewater from stainless-steel industry is the multi-processes of the Pyroma-Electrodialysis-Ion exchange.

• 멤브레인
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• 제21권4호
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• pp.389-397
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• 2011

본 연구에서는 용액 캐스팅법을 이용하여 각기 다른 함량의 VMT가 첨가된 SPAES/VMT 복합막이 제조되었다. SPAES 매트릭스 내의 VMT입자 분산은 전자주사현미경으로 관찰된 평균분포에 의해 확인되었다. 1 wt%보다 적은 함량을 포함한 복합막은 고분자 매트릭스 내에 좋은 분산성을 나타내어 막의 상부층과 하부층에 매끈한 표면을 가졌다. 복합막의 함수율은 온도가 증가함에 따라 급격하게 증가되었으며 VMT는 높은 이온교환능력으로 인하여 강한 수분친화도를 가짐으로 인해 높은 모든 흡착된 수분은 bound water인 것으로 확인하였다. VMT의 함량이 1 wt%보다 적게 첨가된 복합막에서 증가된 이온전도도와 낮아진 메탄올 투과도를 확인할 수 있었다. 모든 복합막 중에서 SPAES/VMT 1.0 wt% 복합막은 선택도 측면에서 가장 뛰어난 연료전지 성능을 가졌으며 Nafion 112과 비교하여 두배 이상 우수한 값을 나타내었다. 이것은 SPAES/VMT 1.0 wt% 복합막이 직접메탄올 연료전지의 구동을 위한 가장 우수한 조건이 될것이라 사료된다.