• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.280-283
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• 2005

The adsorption of a model protein bovine serum albumin (BSA) in expanded bed chromatography was undertaken by exploiting a commercially available expanded bed column (20 mm i.d.) from UpFront Chromatography and Streamline DEAE $(\rho=1.2g/cm^3)$ from Amersham Pharmacia Biotechnology. The influence of whole yeast cells on the adsorption capacity of column was explored by employing yeast cells in a concentration ranged of 0 to $15\%(w/v)$. Equilibrium isotherms for adsorption of BSA on Streamline DEAE were correlated by using Langmuir equation. The presence of yeast cells resulted in decreased of BSA binding capacity in both batch binding and expanded bed chromatography. Results indicated that the yeast cells act as competitor for proteins to bind to the sites on adsorbents.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.113-119
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• 2009

The feasibility of using cork oak bark for phosphorus removal from wastewater was evaluated in this study. Recently, development of more cost-effective media while maintaining high efficiency in pollutants removal has received concern. Barks have a negative surface charge and, hence, tend to show a high affinity to bind cations, and they need to undergo chemical modification to increase their adsorption capacity of anions. Bark was hydrolyzed by HCl solution and it received modification using an aqueous solution of high molecular weight polyethylenimine(PEI). Surface modification with HCl and PEI resulted in a decrease of specific surface area of the bark from $1.932 m^2/g$ to $1.094 m^2/g$. The adsorption experiments were carried out in batch tests and the data were fitted to the Langmuir isotherm and Freundlich isotherm equations. Phosphate removal rate was higher at the lower solution pH possibly due to the form of phosphate ion in solution. For the initial phosphate concentration of 10 mg/L, maximum adsorption was 20.88 mg P/g at pH 3 and 12.02 mg P/g at pH 5. Mechanism of phosphorus sorption onto the HCl-PEI bark was examined through FT-IR spectrometer. Ion exchange between $NH^+$ and $H_2PO_4{^-}$ appeared to be a key mechanism of phosphate adsorption onto the HCl-PEI bark surface.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.268-272
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• 2006

A dense, pellicular UpFront adsorbent ($p=1.5 g/cm^3$, UpFront Chromatography, Cophenhagen, Denmark) was characterized in terms of hydrodynamic properties and protein adsorption performance in expanded bed chromatography. Cibacron Blue 3GA was immobilised into the adsorbent and protein adsorption of bovine serum albumin (BSA) was selected to test the setup. The Bodenstein number and axial dispersion coefficient estimated for this dense pellicular adsorbent was 54 and $1.63{\times}10^{-5}m^2/s$, respectively, indicating a stable expanded bed. It could be shown that the BSA protein was captured by the adsorbent in the presence of 30% (w/v) of whole-yeast cells with an estimated dynamic binding capacity $(C/C_o = 0.01)$ of approximately 6.5 mg/mL adsorbent.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.569-574
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• 2005

In this study, alginic acid that had an high affinity for a heavy metal and was noted for biological adsorbent was modified by an oxidizer, $KMnO_4$. Chemical modification changed hydroxyl of the alginic acid into carboxyl and compare with alginic acid, modified alginic acid exhibited a characteristics that carboxyl groups are comparatively high. For the use of them as an adsorbent, beads were prepared by dropping alginic acid and modified alginic acid solution in dilute 2 wt% $CaCl_2$ solution for non water soluble. The amount of removed $Cu^{2+}$ and $Pb^{2+}$ by modified alginic acid beads showed 84.7 mg and 90.9 mg per gram of beads, respectively. And it showed the amount of adsorbed heavy metal ions 10~20% higher than that of alginic acid beads in range of pH 4~7. In particular, modified alginic acid have a good adsorption capacity for $Cu^{2+}$ and $Pb^{2+}$ by Freundlich adsorption isotherm. According to this study, it is verified that alginic acid that is a nature high molecular substance improved capacity for actual application by increased heavy metal adsorption capacity by chemical modification.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.581-586
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• 2014

The most stable adsorption structures and their corresponding energies of 4-pyridone, 4-hydroxypyridine, 2-pyridone and 2-hydroxypyridine have been investigated by Density Functional Theory (DFT) calculation and high-resolution photoemission spectroscopy (HRPES). We confirmed that between the two reaction centers of 4- and 2-pyridone, only O atom of carbonyl functional group can act as a Lewis base while both the two reaction centers of 4- and 2-hydroxypyridine (tautomers of 4- and 2-pyridone) can successfully function as a Lewis base. On the other hand, owing to their molecular structures, there is a remarkable difference between the adsorption structures of 4- and 2-hydroxypyridine. Through the analysis of the N 1s and O 1s core level spectra obtained using HRPES, we also could corroborate that two different adducts coexist on the surface at room temperature due to their activation energy investigating the coverage dependent variation of bonding configurations when these molecules are adsorbed on the Ge(100) surface.

• Membrane and Water Treatment
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• v.5 no.3
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• pp.171-182
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• 2014

Organic compounds are adsorbed on RO/NF membranes, and the adsorption may influence the rejection of organic compounds by the membranes. Because almost RO/NF membranes are composite membranes, the results obtained by adsorption experiment with using membrane pieces are unable to avoid the influence by the support membrane. In this work, the interaction between membrane polymer and organic solutes was examined by an inverse HPLC methodology. Poly (m-phenylenetrimesoylate), the constituent of skin layer of RO/NF membranes, was coated on silica gel particles and used as a stationary phase for HPLC. When water was used as a mobile phase, almost hydrophilic aliphatic compounds were not effectively adsorbed on the stationary phase, although hydrophobic compounds were slightly adsorbed. The results indicated that the hydrophilic aliphatic compounds are useful probe solutes to examine the molecular sieving effect of a membrane. When water was used as a mobile phase, the aromatic compounds were strongly retained, and therefore $CH_3CN/H_2O$ (30/70) was used as a mobile phase. It was revealed that the adsorption of aromatic compounds was controlled by stacking between solute and polymer and was hindered by non-planar structure and substituents.

• Clean Technology
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• v.17 no.4
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• pp.389-394
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• 2011

A compact adsorption-based process for removal of carbon dioxide and nitrogen from natural gas has been discussed. Among the adsorption-based processes, especially, the pressure swing adsorption (PSA) process has been a suitable unit operation for the purification and separation of gas because of low operation energy and cost. A step cycle is made up of pressurization, feed, equalization, blowdown and rinse. In this work, the PSA process is composed of zeolite 13X and carbon molecular sieve (CMS) for removal of carbon dioxide and nitrogen from mixed gas containing $CH_4/CO_2/N_2$ (75:21:4 vol%). A CMS selectively removes carbon dioxide and a zeolite 13X separates nitrogen from methane. CMS is investigated experimentally due to the high throughput of the faster diffusing component ($CO_2$). The gas composition of top, bottom and feed tank was measured with the gas chromatography (GC) using TCD detector, helium as carrier gas and packed column for analysis of methane, carbon dioxide, and nitrogen.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.180-191
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• 2016

Optimizing energy usage for maximum efficiency is an essential goal for manufacturing plants in every industrial manufacturing sector. The generation and distribution of purifying compressed air is a large expense incurred in practically all manufacturing processes. Not only is the generation and treatment expensive equipment of compressed air, but frequent maintenance and effective operation is also required. As a plant's compressed air system is often an integral part of the production process, it needs to be reliable, efficient, and easy to be maintain. In this paper, we study to find operating method to save energy from the adsorption dryer in the process of purifying compressed air, which is required for a clean room production site in "A" company. The compressed air passes through a pressure vessel with two "towers" filled with a material such as activated alumina, silica gel, molecular sieve or other desiccant material. This desiccant material attracts the water from the compressed air via adsorption. As the water clings to the desiccant, the desiccant particle becomes saturated. Therefore, Adsorption dryer is an extremely significant facility which removes the moisture in the air $70^{\circ}C$ below the dew point temperature while using a lot of energy. Also, the energy consumption of the adsorption dryer can be varied by various operating conditions (time, pressure, temperature, etc). Therefore, based on existing operating experiments, we have searched operating condition to maximize energy saving by changing operating conditions of the facility. However, due to a short experiment period (from September to October), further research will be focused on considering seasonality.

• Journal of environmental and Sanitary engineering
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• v.10 no.2
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• pp.1-12
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• 1995

Under accelerated industrial developments environment pollution comes out to be very stirious. Especially the ions of heavy metal from wastewater, even if they are minimal, accumulated in ecology circle and do finally injury to human health. The general process for removal of heavy metals include coagulation and following sedimentation, ion -exchange and active carbon adsorption and sedimentation that applicate in popular, needs the expense of coagulant the additional treatment of sludge on the general process of coagulation and sedimentation. It is also a serious problem that the second pollution caused by coagulant. However chelating adsorption that uses natural chelating high- molecular compound has not pollution problem Among chelating high- molecules, the diminishing chitin that contained in crustaceans as crawfish and crab in our country with affluent water resources are easy to get. So it is advantageous to use this ubiquitous material for removing heavy metals because we could reuse natural resource. In this research, the author tested the effectiveness of the adsorption and removal of heavy metal ions by chitin and its derivatives. Chitin and cellulose became beads and used as flocculant, in this test. The results are as follows . First, bead showed higher removal ratio than powder in the comparative test on adsorbents such as chitin, chitosan and cellulose. Secondly, in the variety test by the kinds of adsorbent and time. chitosan bead and cellulose bead that showed the highest removal ratio. One hour need to remove the ions of heavy metal. Thirdly, the results of the adsorption degree test by pH revealed high removal ratio adsorption of chitin, cellulose and chitosan bead in alkalin condition but chitosan bead in acidic condition.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.206-212
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• 2013

This study accessed the adsorption characteristics of the 11 perfluorinated compounds (PFCs) on coal-based granular activated carbon (GAC). The breakthrough appeared first for PFODA and sequentially for PFHDA, PFTeDA, PFTDA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, PFOS, and PFHpA. The maximum adsorption capacity (X/M) for the 11 PFCs with apparent breakthrough points ranged from 2.43 ${\mu}g/g$ (for PFODA) to 64.5 ${\mu}g/g$ (for PFHpA). Carbon usage rate (CUR) for PFODA was 0.291 g/day, 11.2 times higher than that for PFHpA (0.026 g/day). The X/M values for the 11 PFCs were fitted well with a linear regression ($r^2$ = 0.89) by their molecular weight (chain length).