• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.459-466
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• 2007

In this study, H-type beta zeolites (BEA) having various metals were used as the adsorbent for the removal of sulfur containing odorants. The different adsorbents containing single or bimetals were utilized to investigate the performance in the individual adsorption of TBM and THT odorants or in the competitive adsorption between them by using a continuous adsorptive bed system. The result shows that the pure H-type BEA zeolite exhibited the highest adsorption capacity for TBM compound, but the higher amount of THT was removed and adsorbed on a HBEA adsorbent having Fe, Pd metal and ZnO oxide. In the case of bimetal containing adsorbents, Cu-Zn/HBEA and Fe-Mo/HBEA showed a higher adsorption capacity for TBM.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.394-401
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• 2014

In order to minimize a building energy consumption with ventilation, a development of smart ventilation system is very important. In this study, a dry adsorbent that is main element of smart ventilation system was developed for removing indoor $CO_2$, and evaluate the adsorption performance. Specific surface area, pore characteristic and crystal structure of the modified sorbent was measured to analyze physical properties. From this analysis, it was found that the developed absorbent has a low specific surface area, due to mesopores of substrate was filled with metal contained raw material. Additionally, through analysis of the adsorption properties, the developed adsorbent was shown a adsorption form of mesopore (type IV), which means adsorption amount was rapidly increased at the part of high-pressure. Order to applying for the field, chamber test was performed. Continuous column tests (2,500 ppm) and batch chamber tests ($4m^3$, 5,000 ppm) showed $CO_2$ removal efficiency of 95% and 88% within 1 hour, respectively.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.10
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• pp.1528-1534
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• 1989

Photoeffects at the p-GaP semiconductor/CsNO3 electrolyte interface were investigated in terms of their current-voltage characteristics. The photoeffects at the semiconductor-electrolyte interfaces and their photocurrent variations are verified using Ar ion laser and continuous cyclic voltammetric methods. The mechanism of charge transfer at the photogeneration in the depletion layer rather than the photodecomposition of the p-GaP semiconductor electrode surface and/or the water photoelectrolysis. The adsorption of Cs+ ions at the interface is physical adsorption.

• Resources Recycling
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• v.15 no.3 s.71
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• pp.66-73
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• 2006

Continuous column adsorption experiments have been conducted fur artificial and actual wastewater which containing $Ni^{2+}$ by using manganese nodule as an adsorbent for the purpose of wastewater treatment along with an increased $Ni^{2+}$ recovery in the refining of manganese nodule. The adsorption features of $Ni^{2+}$ artificial wastewater were examined by taking the height of fixed bed, influent flow rate, and the initial concentration of adsorbate as the influential parameters. The adsorption capacity of manganese nodule and the rate constant for $Ni^{2+}$ adsorption were estimated employing Bohart-Adams equation. In addition, the variation of the adsorbed amount of adsorbate for each column according to the influent flow rate and the initial concentration of adsorbate was investigated based on the breakthrough curves fur each column. For serially connected columns, the adsorbed amount of $Ni^{2+}$ for each column was observed to increase gradually as the adsorption proceeded from the initial column to the final column. The variation of the breakthrough curve for actual wastewater with the height of fixed bed was not so significant as that for artificial wastewater, which was considered to be due to the high concentration of $Ni^{2+}$ in actual wastewater. Regarding the effect of the particle size of manganese nodule on adsorption, the adsorbed amount of adsorbate was found to somewhat increase as the particle size became smaller.

• Mycobiology
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• v.42 no.3
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• pp.249-255
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• 2014

We evaluated a more practical and cost-effective immobilization carriers for ethanol production using the yeast Saccharomyces cerevisiae. Three candidate materials-rice hull, rice straw, and sawdust-were tested for their cell-adsorption capacity and operational durability. Derivatizations of rice hull, rice straw, and sawdust with the optimal concentration of 0.5 M of 2-(diethylamino)ethyl chloride hydrochloride (DEAE HCl) resulted in > 95% adsorption of the initial yeast cells at 2 hr for DEAE-rice hull and DEAE-sawdust and in only approximately 80% adsorption for DEAE-rice straw. In addition, DEAE-sawdust was found to be a more practical carrier for immobilizing yeast cells in terms of operational durability in shaking flask cultures with two different speeds of 60 and 150 rpm. Furthermore, the biosorption isotherms of DEAE-rice hull, -rice straw, and -sawdust for yeast cells revealed that the $Q_{max}$ of DEAE-sawdust (82.6 mg/g) was greater than that of DEAE-rice hull and DEAE-rice straw. During the 404-hr of continuous column reactor operation using yeast cells immobilized on DEAE-sawdust, no serious detachment of the yeast cells from the DEAE-sawdust was recorded. Ethanol yield of approximately 3.04 g/L was produced steadily, and glucose was completely converted to ethanol at a yield of 0.375 g-ethanol/g-glucose (73.4% of the theoretical value). Thus, sawdust is a promising practical immobilization carrier for ethanol production, with significance in the production of bioethanol as a biofuel.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.729-736
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• 2011

This work is to compare the experiment results by a continuous fixed-bed adsorption of water vapor, acetone vapor, and toluene vapor on zeolite 13X (SAU) and silica-alumina (SAK). SAU and SAK have very different pore structure but similar composition as inorganic adsorbent. The relationship between the equilibrium adsorption capacity and specific pore size range were studied. Adsorption of water vapor was more suitable on SAU than SAK because SAU has relatively more developed pores around $5\;\AA$ than SAK in the pore range of $10\sim100\;\AA$. Adsorption of acetone vapor was more suitable on SAK than SAU because SAK has relatively more developed pores around $5\sim10\;\AA$ than SAK in the pore range of less than $10\;\AA$. Adsorption of toluene vapor was more suitable on SAK than SAU because SAK has relatively more developed pores in the pore range of $10\sim100\;\AA$ than SAK. Adsorption capacity of the adsorbent was closely related to the surface area generated in the specific pore size region. But it was difficult to distinguish the relationships between adsorption capacity and micro area, and the external surface area of adsorbent.

• Environmental Engineering Research
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• v.7 no.1
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• pp.33-37
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• 2002

The two kinds of pellet-type red-mud adsorbents (bead-type, crushed-type) were from red mud, which is generated as a by-product during the production of aluminum hydroxide from bauxite ore. The adsorption experiments of Pb^{2+} ion in the aqueous solution by these red-mud adsorbents were studied with a continuous adsorption ccolumn. As a result, the crushed-type adsorbent shows better performance in adsorption of Pb^{2+} than the bead-type adsorbent between the two types of the pellet-type adsorbents. The continusous adsorption experiment shows that the pellet-type adsorbents made from red mud have good performance for removal of Pd^{2+}. The breakthrough curves of the red-mud adsorbents were compared with that of activated carbon.

• Advances in environmental research
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• v.4 no.2
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• pp.135-142
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• 2015

In this study, we evaluated the adsorption/desorption of uranium (U) in pure soil environment using continuous column reactor. We additionally investigated the adsorption/desorption mechanism of U on vivianite surface in molecular scale using quantum calculation. We observed that below $0.1{\mu}M$ of U was detected after 20 d from U injection ($1{\mu}M$) in adsorption test. However, all of absorbed U was detached from vivianite surface in 24 h by injection of CARB solution ($1.44{\times}10^{-2}M\;NaHCO_3$ and $2.8{\times}10^{-3}M\;Na_2CO_3$). Based on exchange energy calculation, we found that $UO_2(CO_3)_2{^{2-}}$ and $UO_2(CO_3)_3{^{4-}}$ species have higher repulsive energy than $UO_2(OH)_2$ species. The results obtained from this study could be applied to predict the behavior of uranium in contaminated and remediation sites.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1123-1129
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• 2015

This research was performed by means of several different virgin granular activated carbons (GAC) made of each coal, coconut and wood, and the GACs were investigated for an adsorption performance of iodine-131 in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of the virgin two coals-, coconut- and wood-based GACs were observed as bed volume (BV) 7080, BV 5640, BV 5064 and BV 3192, respectively. The experimental results of adsorption capacity (X/M) for iodine-127 showed that two coal- based GACs were highest (208.6 and $139.1{\mu}g/g$), the coconut-based GAC was intermediate ($86.5{\mu}g/g$) and the wood-based GAC was lowest ($54.5{\mu}g/g$). The X/M of the coal-based GACs was 2~4 times higher than the X/M of the coconut-based and wood-based GACs.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.155-160
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• 2007

Constructed wetland has been widely used for the treatment of sewage, stormwater runoff, industrial wastewater, agricultural runoff, acid mine drainage and landfill leachate. For the removal of nitrogen and phosphorus, uptake by plants and adsorption to media material are the major processes, and, therefore, the selection of media with specific adsorption capacity is the critical factor for the optimal design of wetland along with the selection of appropriate plant species. In this study, two media materials (loess bead and mixed media) possessing different adsorption characteristics for ammonium and phosphate were selected, and their adsorption characteristics were evaluated. In addition, the performance of subsurface-flow wetland systems employing these media was evaluated in both batch and continuous flow systems. With LB medium, beter phosphorus removal was observed, while better ammonia removal was obtained with MM medium. In addition, enhanced removal efficiencies were observed in the wetland systems employing both media and aquatic plants, mainly due to the better environment for microbial growth. As a result, appropriate selection or combination of media with respect to the inflow water quality maybe important factors for the successful design and operation of wetland systems.