• Analytical Science and Technology
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• v.12 no.2
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• pp.159-165
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• 1999

The adsorption and separation behaviors of transition metal ions using a merrifield resin bound 1,12-diaza-3,4:9,10-dibenzo-5,8-dioxacyclopentadecane (NTOE) and 1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane(NDOE) were investigated in aqueous solution. The orders of adsorption degree(E) and distribution ratio(D) of transition metal ions were Cu(II)$t_R$) of metal ions were affected by adsorption degree(E) and distribution ratio(D). This results showed good separation efficiency of Ag(I) from mixed metal solution.

• Analytical Science and Technology
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• v.11 no.4
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• pp.248-253
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• 1998

The adsorption and separation behaviors of alkali, alkaline earth and transition metal ions using a poly-dibenzo-18-crown-6 were investigated in aqueous solution. The adsorption degree(E) and distribution ratio(D) of alkali, alkaline earth metal ions were Li(I)$t_R$) of metal ions were affected by the adsorption degree(E) and distribution ratio(D). This results showed good separation efficiency of K(I), Sr(II), Ag(I) and Pb(II) from the mixed metal solution.

• Resources Recycling
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• v.20 no.6
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• pp.28-36
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• 2011

The adsorption of nickel(Ni) from sulfuric acid solution was carried out by ion exchange method. A series of batch tests in synthetic solutions were carried out using Lewatit Monoplus TP 220 resin. The following experimental parameters, such as temperature, shaking rate, reaction time, pH, resin dosage and concentration of nickel ions etc. were investigated to establish the effective optimum conditions of nickel adsorption. The solution pH(2.0~5.0) and shaking rate had little effects on the adsorption of nickel and adsorption time of 72hours was required to reach equilibrium. The experimental results show a good agreement with Feundlich isotherm and pseudo-second order reaction. The adsorption behavior of Ni obtained from synthetic solution was compared with that of waste electroplating solution. Elution of nickel from loaded resin increased with increase in $H_2SO_4$ concentration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.190-197
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• 2000

Anions such as C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, P $O_4$$^{3-}$, and organic anions, that do not become a part of the clay mineral crystal lattice, are of considerable interest in soils which are a potential sink caused by acid rain. In this paper, elution of native sulfate and breakthrough curves (BTC) were obtained from miscible displacement of non-specifically or specifically adsorbed anions through non-saturated or saturated Bt soil of Chungwon series. The shape and position of the BTC's could be affected by adsoprtion and ion exchange onto the soil particle surfaces. Measured BTC's for oxalic acid under unsaturated and saturated conditions showed that less pore volumes were required to displace the native S $O_4$$^{2-}$S from the soil column, and that maximum detection limit of oxalic acid reached earlier than under unsaturated. The retarded BTC's to the righthand side could be attributed by different adsorption behavior of each anion, although BTC's may be influenced by the smaller order of velocity change. The alternate breakthrough and elution curves show the rapid approach to the maximum detection limit of C/Co = 1, compared to progressive tailing of elution curve to reach to C/Co = 0. The probable explanation for asymmetric elution patterns for both anion is that the anion was selectively adsorbed on the positively charged soil surface from the solution passing in the soil column. On the other hand, the variations of pH in effluent showed that pH was increased to 7 in the first 6 pore volume and then gradually decreased to pH 4.

• Membrane Journal
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• v.18 no.4
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• pp.306-316
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• 2008

The adsorption characteristics of L-tryptophan of PES-BSA affinity membranes prepared by using electro-spinning were investigated. It was found that the fiber diameters could be controlled by the comparisons of fiber diameters prepared by various spinning conditions through FESEM and Image Analyzer. Darcy's permeability constants, mechanical properties and hydrophobic properties were enhanced since micro-fibers increased by increasing the composition ratio of HFB and BSA. The elution capacity of L-tryptophan in borate-DMSO buffer solution was higher than that in tris-HCl buffer solution, while the elution capacity of A 7906 type BSA was higher than A 8022 type BSA. This is due to the characteristics of BSA type, i. e. higher purity and uniform molecular weight and better pH stability of A 7906 type BSA than those of A 8022 type BSA.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.128-135
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• 2005

Mixed-mode hydrophobic/ionic matrices exhibit a salt-tolerant property for adsorbing target protein from high-ionic strength feedstock, which allows the application of undiluted feedstock via an expanded bed process. In the present work, a new type of mixed-mode adsorbent designed for expanded bed adsorption, Fastline $PRO^{\circledR}$, was challenged for the capture of nattokinase from the high ionic fermentation broth of Bacillus subtilis. Two important factors, pH and ion concentration, were investigated with regard to the performance of nattokinase ad-sorption. Under initial fermentation broth conditions (pH 6.6 and conductivity of 10 mS/cm) the adsorption capacity of nattokinase with Fastline PRO was high, with a maximum capacity of 5,350 U/mL adsorbent. The elution behaviors were investigated using packed bed adsorption experiments, which demonstrated that the effective desorption of nattokinase could be achieved by effecting a pH of 9.5. The biomass pulse response experiments were carried out in order to evaluate the biomass/adsorbent interactions between Bacillus subtilis cells and Fastline PRO, and to demonstrate a stable expanded bed in the feedstock containing Bacillus subtilis cells. Finally, an EBA process, utilizing mixed-mode Fastline PRO adsorbent, was optimized to capture nattokinase directly from the fermentation broth. The purification factor reached 12.3, thereby demonstrating the advantages of the mixed-mode EBA in enzyme separation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.495-499
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• 2004

The analyses of peak shapes in chromatography are useful in operating chroma­tographic system. The asymmetry and sharpness of a chromatographic peak are estimated by the reversed-phase adsorption of two standard peptides (angiotensin II bradykinin) on $C_{18}$ In this work, the average particle diameters of $C_{18}$ were 5 and 15 $\mu$m, while the pore sizes were 100 and 300 A. The composition of the mobile phase was $50/50\;vol.\;{\%}$ of a binary mixture of acetonitrile and water with $0.1\%$ TFA, and the particles were packed in a stainless column ($4.6{\times}150$ mm). The third and the fourth central movement were calculated from the chromatographic elution curves by moment analysis. The peak asymmetry was determined by two theoretical calculations: the asymmetry factor by elution peak analysis and skewness with moment analysis. The sharpness was estimated by the fourth central moment. In this work, the most acceptable skewness was calculated when the pore size was 300 A. The large excess was observed on small pore size.

• Resources Recycling
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• v.27 no.2
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• pp.48-54
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• 2018

Batch ion exchange experiments of Au(III) were performed from ammonium chloride solution by employing strong anionic exchange resins (Amberlite IRA 402 and AG 1-X8). Au(III) was well loaded into the two resins and the loading behavior of Au(III) into AG 1-X8 was superior to that into Amberlite IRA 402. The loading of Au(III) into AG 1-X8 followed Langmuir adsorption isotherm and the experimentally determined loading capacity was 355 mg/g. Au(III) was successfully eluted by $HClO_4$ from the loaded AG 1-X8 and the elution percentage of Au(III) increased with the concentration of $HClO_4$.

• Journal of the Korean GEO-environmental Society
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• v.9 no.4
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• pp.47-52
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• 2008

In this study, it was analyzed the soil components and elution characteristics of heavy metal ions in sediment samples to examine the effect of sediments embedded in Andong and Imha reservoirs on water quality. Major elements of sediments were shown to be Al, Si, K, and Fe by EDS analysis and major soil components of the collected 6 different sediments were illite (I), kaolinite (Ka), quartz (Q) and feldspar (F). And especially quartz took up a considerable part of sediments by XRD analysis. The total concentrations of Zn, As, Cr, Cu and Pb in sediments of Andong reservoir were relatively higher than those of Imha reservoir. The elution property of heavy metal from sediments had various aspects according to pH. Among the heavy metals in Andong reservoir sediments, As and Zn were significantly eluted at pH 6 compared with the other heavy metals. In the case of the adsorption tests using the sediments, the adsorptive capacities of Zn, Cd and Cu were very weak, on the while those of Pb and Cr were high.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.347-360
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• 2010

In order to develop the multi-residue purification method for 180 pesticides commonly used in Korea, many analytical methods on individual and multi- pesticide residues in the agricultural commodities and food product were examined. Through the modification of adsorption chromatographic methods used in Europe, the United States and Korea, the Florisil and silica-gel chromatographic systems were developed. Through these purification systems, elution profiles for all pesticides were examined. As the results, 145 pesticides were recovered in the range of 70-120% in Florisil clean-up system. The distribution of pesticides in the elution profile was 12 pesticides in the first fraction, 76 pesticides in the second fraction, 81 pesticides in the third fraction, 60 pesticides in the fourth fraction and 30 pesticides in the last fraction. And, in silica-gel system, 137 pesticides were recovered in the range of 70~120%. The distribution of pesticides in the elution profile was 22 pesticides in the first fraction, 59 pesticides in the second fraction, 102 pesticides in the third fraction, 46 pesticides in the fourth fraction and 8 pesticides in the last fraction.