• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.472-478
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• 2013

Cu and Cr as a base metal and Pt, Pd as a supportive metal were selected for improving adsorption capacity of activated carbon fiber in eliminating especially targeted VOCs. Preparing variables such as metal loading, loading temperature, loading hours and kinds of loaded metals were changed. Properties measurement was carried out by SEM (scanning electron microscope), XRF (x-ray fluorescence analysis) and EDX (Energy Dispersive X-ray spectrometer) and adsorption capacity evaluation were also performed by gas analyzer. Under this study, the adsorption capacity of complex metal loaded activated carbon fiber was improved positively than that of single metal loaded activated carbon fiber. And we found that the best conditions for metal loading were 5 hours loading time at $100^{\circ}C$ and the adsorption capacity was enhanced almost double compared with other condition based activated carbon fiber. Cu-Cr-Pt-Pd loaded activated carbon fiber showed the best adsorption capacity. Also we confirmed that more than 0.5 second is necessary for adsorbate diffusion and adsorption over activated carbon fiber.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.467-473
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• 2008

Natural organic matter (NOM) removal by physico-chemical adsorption and biological oxidation was investigated in five slow sand filters with different media depths. Non-purgeable dissolved organic carbon(NPDOC) and $UV_{254}$ absorbance were measured to evaluate the characteristics of NOM removal at different filter depths. Removal efficiency of NOM was in the range of 10-40% throughout the operation time. At start-up of the filters packed with clean sand media, NOM was probably removed by physico-chemical adsorption on the surface of sand through the overall layer of filter bed. However, when Schumutzdecke layer was built up after 30 days operation, the major portion of NPDOC was removed by biological oxidation and/or bio-sorption in lower depth above 50 mm. NOM removal rate in the upper 50 mm filter bed was $0.82hr^{-1}$. It was about 20 times of the rate($0.04hr^{-1}$) in the deeper filter bed. Small portion of NPDOC could be removed in the deeper filter bed by both bio-sorption and biodegradation. SEM analysis and VSS measurement clearly showed the growth of biofilm in the deeper filter bed below 500 mm, which possibly played an important role in the NOM removal by biological activity besides the physco-chemical adsorption mechanism

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.310-318
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• 1999

The concentration breakthrough curves were examined to predict mass transfer coefficients of nitrogen and oxygen in adsorption column for design data of PSA process. Experimental breakthrough curves for bulk gas flow were compared with theoretical simulation results. For quantitative analysis of the adsorption, coupled Langmuir isotherm was considered and LDF model was used to describe the mass transfer effect. In the experimental and theoretical results, it was found that mass transfer coefficient was not affected by flow rate but strongly affected by pressure. As a result of this tendency, mass transfer resistance in this system was proved to belong to the macropore diffusion controlling region and the mass transfer coefficients could be expressed by exponential functions of pressure change. The mass transfer coefficients for one component, nitrogen or oxygen, were successfully applied to breakthrough curves for bulk mixed gases. The experimental curves were reasonably in consistent with the theoretical curves and the error time was less than 5 percent.

• Journal of Industrial Technology
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• v.23 no.A
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• pp.199-206
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• 2003

The charcoal-encapsulated methyl silica microcapsules were prepared by a O/W microemulsion sol-gel method, and the adsorption properties on aquatic humic acid were investigated. The capsules prepared were spherical, $100{\sim}1000{\mu}m$ in size. The size distribution was controllable by adjusting the size of charcoal powder, charcoal/methyl silica ratio, and agitating speed in O/W sol-gel process. Adsorption efficiency of charcoal for aquatic humic acid was decreased after encapsulation by methyl silica shell. The decreased adsorption efficiency can be dependent on the decrease of the BET surface area and pore volume after encapsulation. Diffusion properties of humic acid through the capsule shell also played an important role on adsorption efficiency. Therefore, the reasonable target pollutants for the capsules can be VOC or odor molecules which can overcome diffusion barrier through shell of capsules in air condition. Functionalization methods for the charcoal-encapsulated $CH_3(SiO)_n$ microcapsules by incorporation of $TiO_3$ as a phtocatalytic function and by incorporation of inorganic pigment as a color function were also investigated. $TiO_2$ coating properties were controllable by adjusting pH, temperature, and the concentration of $TiOSO_4$. In XRD measurement, the crystal form of the coated $TiO_2$ was anatase. For the colorization of the capsules, inorganic pigments were more efficient than organic dyes, and various color was introduced to the capsules using inorganic pigments.

• Economic and Environmental Geology
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• v.28 no.5
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• pp.455-467
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• 1995

In order to investigate the dispersion patterns and speciations of Cu, Pb, Zn and Cd in soils, stream sediments and stream waters, geochemical studies of soil, stream sediment and stream water samples collected in the vicinity of the Shi-Heung Cu-Pb-Zn mine was carried out Cation exchange capacity measurement, size analysis, X-ray diffraction analysis and batch test were performed to select applicable soil for adsorption treatment The average content of Cu, Pb, Zn and Cd in soils collected from tailings and ore dressing plant is 1084 ppm, 2292 ppm, 3512 ppm and 29.2 ppm, respectively, and therefore, tailings and ore dressing plant site may be the major contamination sources in this study area. The mean content of Cu, Pb, Zn and Cd in stream sediments is extremely high up to 794 ppm, 1633 ppm, 2946 ppm and 25.2 ppm, respectively. Tailing particles and heavy metal ions are dispersed along the tributary system. Results from the sequential extraction analysis indicate; (1) most of Cu is bound to organic matters and sulphides, (2) fraction of Pb is mainly bound to Fe and Mn oxides. Most of Zn is largely bound to Fe and Mn oxides and residual fraction. Ion exchangeable fraction of Cd is relatively higher than those of Cu, Pb and Zn. Batch test on soils collected from the kaolinite and/or pyrophyllite mines and from the control areas was carried out to select an applicable soil samples for adsorption treatment The sample, S10, collected from the control area 2 (clay content 33.2%) shows the highest $K_d$ (distribution coefficient). Organic content in soils and several clay minerals shows relatively good correlation with $K_d$. It means that applicable soils for adsorption treatment of heavy metals show high organic and clay content.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.396-397
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• 2008

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.536-539
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• 2003

This study area has been contaminated by oils. To identify contaminated ranges and to assess the possibility of contamination dispersion, monitoring wells were installed and slug test, field soil permeability test, automatic or manual measurement of groundwater table, and groundwater quality analyses in field and laboratory were performed. In addition, a groundwater modeling program was used to assess the possibility of oil contamination dispersion, based on field data and groundwater quality data. The results showed that concentration of oil contaminants in groundwater have been decreased by dispersion and adsorption.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.4
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• pp.349-356
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• 2016

Volumetric capacity metrics at cryogenic condition are critical for technological and commercial development. It must be calculated and reported in a uniform and consistent manner to allow comparisons among different materials. In this paper, we propose a simple and universal protocol for the determination of volumetric capacity of sorbent materials at cryogenic condition. Usually, the sample container volume containing porous sample at RT can be directly determined by a helium expansion test. At cryogenic temperatures, however, this direct helium expansion test results in inaccurate values of the sample container volume for microporous materials due to a significant helium adsorption, resulting significant errors in hydrogen uptake. For reducing this container volume error, therefore, we introduced and applied the indirect method such as 'volume correction using a non-porous material', showing a reliable cold volume correction.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.267-275
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• 1997

$ZrO_2$ Powder was Prepared by sol-gel process and the adsorption characteristic of cobalt($Co^{2+}$) by $ZrO_2$ adsorbent in high-temperature water was investigated using batch adsorption experiment with a stirred autoclave. The prepared $ZrO_2$ was calcined at $600{\sim}1400^{\circ}C$ and analyzed by X-ray diffractometry, SEM, BET surface area, FT-IR and TG-DTA measurement. The tetragonal Phase of $ZrO_2$ is produced $480^{\circ}C$ from amorphous gel at temperature $480^{\circ}C$. Both tetragonal and monoclinic phase of $ZrO_2$ exist at temperature between $600^{\circ}C$ and $1000^{\circ}C$. At temperature $1200^{\circ}C$, tetragonal to monoclinic phase trasition is occurred. The $Co^{2+}$ adsorption capacity of $ZrO_2$ calcined at $600^{\circ}C$ for 4 hours is 0.16 meq $Co^{2+}/g$ adsorbent in the high temperature at $250^{\circ}C$. The adsorption of $Co^{2+}$ on the $ZrO_2$ adsorbent is irreversible endothermic in the temperature range ($125-175^{\circ}C$). The standard enthalpy change (${\Delta}H^{\circ}$) of $ZrO_2$ calcined at $600^{\circ}C$ for 4 hours is 18 kJ/gmol.

• Membrane Journal
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• v.32 no.5
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• pp.348-356
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• 2022

With the development of the bio industry, membrane chromatography with a high adsorption efficiency is emerging to replace the existing column chromatography used in the downstream processes of pharmaceuticals, food, etc. In this study, through the deacetylation reaction of two commercial cellulose acetate (CA) membranes with different pore sizes, the porous regenerated cellulose (RC) supports for membrane chromatography were obtained to attach the anion exchange ligands. The adsorptive membranes for anion exchange were prepared by attaching an anion exchange ligand ([3-(methacryloylamino) propyl] trimethylammonium chloride) containing quaternary ammonium groups on the RC supports by grafting and UV polymerization. The protein adsorption capacities of the prepared membranes were obtained through both the static binding capacity (SBC) and the dynamic adsorption capacity (DBC) measurement. As a result, the membrane chromatography with the smaller the pore size, the larger the surface area showed the highest protein adsorption capacity. Membrane chromatography which was prepared by using deacetylated commercial CA support with MAPTAC ligand (i.e., RC 0.8 + MAPTAC: 43.69 mg/ml, RC 3.0 + MAPTAC: 36.33 mg/ml) showed a higher adsorption capacity compared to commercial membrane chromatography (28.38 mg/ml).