• 환경위생공학
• /
• 제16권2호
• /
• pp.91-99
• /
• 2001

Cross linked chitosan beads showed high selective adsorption abilities in order of $Au^{3+}$ > $Hg^{2+}$ > $Cu^{2+}$ > $Cd^{2+}$ > $Pt^{4+}$ > ${UO_2}^{2+}$ ions in mixed solution of various metal ions at pH 4.5. N-methyltyiobenzylated chitosan beads(MTB-chitosan beads) were prepared treating with p-(methylthio) benzaldehyde after cross linking of chitosan beads to give them a high selectivity in adsorption of metal ions. The MTB-chitosan beads demonstrated their selectivity on precious metals among various metal ions distinctively. Particularly, the MTB-chitosan had a peculiar selective adsorption on $Pd^{2+}$, $Au^{2+}$, and $Hg^{2+}$ions whilst the cross linked chitosan beads showed its high adsorption on $Pd^{2+}$ at pH 1.1. On the other hand, the cross linked chitosan beads showed its superiority in selective adsorption on $Au^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ions to the MTB-chitosan at pH 4.5 of the test solution. Thus metal selectivities were given to chitosan beads through chemical modifications.

• Bulletin of the Korean Chemical Society
• /
• 제32권7호
• /
• pp.2217-2221
• /
• 2011

We investigated the selective deoxyribonucleic acid (DNA) adsorption on layered double hydroxide (LDH) nanoparticles via studying the interaction between positively charged LDH nanoparticle as adsorbent and negatively charged adsorbates such as methyl orange (MO), fluorescein (FL), and DNA strands. The size controlled LDH $(Mg_{0.78}Al_{0.22}(OH)_2(CO_3)_{0.11}{\cdot}mH_2O)$ was prepared by conventional coprecipitation method, followed by the hydrothermal treatment. According to the adsorption isotherms, the adsorbed amounts of MO and FL were similar, however, that of DNA were much larger. The adsorption behaviors were well fitted to Freundlich adsorption model. The concentration dependent adsorption behavior on LDH surface was described in order to verify the selective DNA separation ability. The result showed that the LDH has advantages in selective adsorption of DNA competing with single molecular anions.

• KSBB Journal
• /
• 제11권6호
• /
• pp.726-732
• /
• 1996

은행나무( Ginkgo bilaha 1.)의 잎으로부터 flavo­n noids 화합물틀을 Amberlite XAD-7으로 흡착시 키 는 최적 조건에 대한 연구를 수행하였다. 흡착제의 투입량, 수용액의 pH, 수용액의 조성 등의 흡착 조 건을 달리 하면서 flavonoids 화합물들의 흡착 경향 을 조사한 결과 20% 의 에탄올이 첨가된 pH 5.0의 수용액에 XAD-7이 15g/L의 양으로 투입된 경우 가장 선택적인 흡착이 이루어졌다. 이 경우 유기용 매 추출에 비해 약 98% 이상의 flavonoids 화합물 이 XAD-7에 흡착되었으며 selectivity도 약 50% 이상 증가된 85%를 나타내었다. 잎 내에 존재하는 여러 가지 화합물들 중 극성인 물질들은 수용액 내 에 용해되어 분리가 이루어졌고 flavonoids 화합물 에 비해 비극성인 지용성 물질들과 polyphen이류 등 은 흡착제가 투입되면 hydrophobic attraction에 의해 aggregation을 이루면서 석출이 되었다. 이로 인해 flavonoids 화합물들만이 흡착제로 이통하게 되 었다. 이와 같은 흡착 공청은 기존의 유기용매 추출 법에 비해 공정에 소요되는 경비와 시간을 크게 감 소시켜 새로운 분리 방법의 지표를 제시할 수 있을 것으로 기대된다.

• Membrane and Water Treatment
• /
• 제14권3호
• /
• pp.121-128
• /
• 2023

This study introduces a NaOH/Zn-assisted hydrothermal method for the synthesis of zeolites derived from coal ash (CA). A zeolite/Zn adsorbent is successfully prepared by the activation of CA with NaOH and Zn; it is characterized by a high surface area and a negative surface charge.Methylene blue (MB) and methyl orange (MO) are selected as dye pollutants, and their adsorption onto the zeolite/Zn adsorbent is investigated. Results show the high adsorption capacities of MB and MO and that the negative surface charge facilitates electrostatic interactions between the adsorbates and adsorbents. The zeolite/Zn adsorbents shows the selective adsorption of positively charged dye MB via electrostatic interactions between the =NH+ group (positive dipole) and the oxygen functional group of the adsorbents (negative dipole). The selectivity for the positively charged dye is sufficiently high, with the removal efficiency reaching 99.41% within 10 min. By contrast, the negatively charged dye MO exhibits negligible absorption. These findings confirm the role of electrostatic interactions in the adsorption of MB, in addition to the effect of a large surface area. The results of this study are expected to facilitate the development of simple, eco-friendly, and cost-effective zeolite-based adsorptive composites from CA residuals for the selective removal of dye pollutants from CA waste.

• 품질경영학회지
• /
• 제43권3호
• /
• pp.359-372
• /
• 2015

Purpose: Through studying the expert's and non-experts panel responses to the questions regarding the attributes of chemical-biological protection cloth quality in terms of the levels of customer demand and technical factors has been studied. We are applied to a QFD matrix with find out the relationship between the selective removal efficiency of chemical-biological cloth and the guidelines of technical approach. Methods: We fabricated several composite of ion-exchange resins with selectively permeable performance designed to facilities water vapor transport and selective adsorption of the harmful gases. With these materials, we characterized on the selectively permeable performance to identify ion-exchange resin with chemical-biological protective cloth. Results: Results showed that ion exchange materials possessed performance with selectively efficiencies as NH3, SOx, NOx and HCl gas. The selective adsorption amount of ammonia and hydrogen gases were $90-80{\mu}g/g$ with TRILITE SCR-BH sulfonated ion exchange resin. The PP non-woven/ion exchange resin adsorbent materials possessed performance with water vapor permeability were 1,100-1,350 g/m2/day, it's was two times high value compare with activated carbon. With these materials, we characterized selectively removal efficiency to identify new ion-exchange material with chemical-biological protective capability. Conclusion: This study shows that a QFD aids in deciding with of the adsorption parameters to optimized with chemical-biological protection cloth manufacturing.

• Korean Chemical Engineering Research
• /
• 제53권3호
• /
• pp.269-275
• /
• 2015

질산이온 선택성 탄소전극(NSCE, nitrate-selective carbon electrode)에서 전원공급 방식에 따른 이온들의 흡착특성을 분석하였다. 질산이온에 선택성이 높은 음이온수지 분말을 탄소전극에 코팅하여 NSCE를 제조하였다. 질산과 염소이온의 혼합용액에 대해 정전압(CV, constant voltage)과 정전류(CC, constant current) 모드에서 축전식 탈염(CDI, capacitive deionization)을 실시하였다. 이온들의 총 흡착량은 CV 모드로 운전한 경우 CC 모드에 비해 약 15% 증가하였다. 혼합용액에서 질산이온의 비율은 26%로 낮았지만 흡착된 질산이온의 몰비율은 최대 58%로 나타나 NSCE가 질산이온을 선택적으로 제거하는데 효과적임을 확인하였다. CC 모드에서 운전한 경우 흡착된 질산이온의 몰비율은 흡착기간 동안 55~58%로 일정하였다. 반면 CV 모드에서는 30~58%로 큰 차이를 보였다. 이를 통해 셀에 공급되는 전류가 질산이온의 선택적 제거율을 결정하는데 중요한 인자임을 알 수 있었다.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2004년도 학술논문집
• /
• pp.119-120
• /
• 2004

A study on the selective adsorption of uranium(VI) from a high concentration of chemical salts has tern peformed to investigate the uranium removal mechanisms and the application conditions of the electrosorption technique using the activated carbon fiber(ACF) as a good conductive electrosorption adsorbent. Electrosorption test were carried out using an electrochemical cell.(omitted)

• KSBB Journal
• /
• 제25권5호
• /
• pp.466-470
• /
• 2010

본 연구에서는 자석으로 분리가 가능한 polyaniline nanofiber (PAMP)를 개발하여 선택적인 에탄올 흡착 및 탈착공정을 활용하여 에탄올을 농축하였다. 개발된 PAMP는 용액 중에 있는 에탄올을 80%이상 흡착하였다. 자석을 활용하여 PAMP에 흡착된 에탄올의 회수가 가능하였으며, 물리적인 힘을 통하여 에탄올 탈착이 가능하여 에탄올의 회수가 용이하였다. 본 연구에 개발된 PAMP는 지속적인 재활용이 가능하였다. 본 연구에서 PAMP를 10회 반복 사용하였을 때 PAMP의 에탄올 흡착율은 최초 사용한 경우의 92%를 유지하여 PAMP를 지속적으로 활용할 수 가능성을 확인하였다. 본 연구에서 개발된 PAMP를 사용하여 46 g/L의 저농도 에탄올을 197.6 g/L의 고농도 에탄올로 농축이 가능하였다.

• Nuclear Engineering and Technology
• /
• 제54권8호
• /
• pp.3017-3026
• /
• 2022

The ¹³¹Cs radioisotope with a short half-life time and high average radiation energy can treat the cancer effectively in prostate brachytherapy. The typical ¹³¹Cs production processes have a separation step of the cesium from ¹³¹Ba to obtain a high specific radioactivity. Herein, we suggested a novel ¹³¹Cs separation method based on the Ba²⁺ adsorption of alginate beads. It is necessary to reduce the affinity of alginate beads to cesium ions for a high production yield. The carboxyl group of the alginate beads was replaced by a sulfonate group to reduce the cesium affinity while reinforcing their affinity to barium ions. The modified beads exhibited superior Ba²⁺ adsorption performances to native beads. In the fixed-bed column tests, the saturation time and adsorption capacity could be estimated with the Yoon-Nelson model in various injection flow rates and initial concentrations. In terms of the Cs elution, the modified alginate showed better performance (i.e., an elution over 88%) than the native alginate (i.e., an elution below 10%), indicating that the functional group modification was effective in reducing the affinity to cesium ions. Therefore, the separation of cesium from the barium using the modified alginate is expected to be an additional option to produce ¹³¹Cs.

• Bulletin of the Korean Chemical Society
• /
• 제28권8호
• /
• pp.1346-1352
• /
• 2007

This article presents an original work on kinetically studying the selective adsorption and recognition by molecularly imprinted polymer (MIP). With S-naproxen as template, the imprinted polymer was prepared. The result indicates that the prepared polymer shows a more complicated sorption toward S-naproxen than toward its enantiomer R-naproxen. The rate constant in the case of template appears to be a variable. There are also significant deviations from the idealized Langmuir model. Related information indicates that these, in logic, can be a result of biomimic structural and functional complements between imprint and the template, which makes the polymer capable of selectively recognizing the imprint species.