• Journal of Environmental Science International
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• v.4 no.5
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• pp.527-534
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• 1995

The waste biomass of Sacchromyces uvarum, used in fermentation industries to produce ethanol, were studied for their ability to absorb various heavy metal ions. Heavy metal ions studied in this research were Cd, Co, Cr, Cu, Ni and Pb. The order of the sorption capacity was Pb>Cu>Co=Cr=Cd>Ni. The living Sacchromyces uvarum exhibited higher metal-uptake capacity than the dead Sacchromyces uvarum. After we compare the uptake capacity of the Sacchromyces uvarum for individual metal ions with for a mixture of them, the following was observed: in the mixed heavy metal solution the uptake capacity was decreased than the one heavy metal solution. The selective uptake was observed when all . the heavy metal ions were dissolved in a mixed solution. The adsorption isotherm modelling was decribed with the Langmuir and Freundlich model. The results were in good agreement with the Langmuir model.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.6
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• pp.325-331
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• 2017

Adsorption experiments of carbon dioxide were performed on ZSM5 and Molecular Sieve 13X (MS13X) impregnated with Monoethanol Amine (MEA). Adsorption efficiency of $CO_2$ was investigated in a U type packed column with GC/TCD. The adsorption capacities of adsorbents are estimated in the temperature range of $30-80^{\circ}C$. The modified adsorbents was characterized by BET surface area, $N_2$ adsorption/desorption isotherms, X-ray diffraction and FT-IR. Surface analysis results showed that the impregnation method did not affect the crystallinity of any adsorbents. BET surface area of the MS13X impregnated amine decreased to $19.945m^2/g$ from $718.335m^2/g$. These reults showed that amine molecules were filled with the pore volume in MS13X, as a results restricting access of nitrogen into the pores. The MEA modified MS13X showed improvement in $CO_2$ adsorption capacity over the ZSM5 impregnated with MEA. The MS13X-MEA showed the highest adsorption capacity due to physical adsorption and chemical adsorption by amino-group content. This results also showed that adsorption capacity of MS13X-MEA increases with the temperature range of $60-80^{\circ}C$ compared with pristine MS13X.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.111-117
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• 1989

The optimum reaction conditions for the acid consuming capacity of aluminum silicate synthesized from the reaction of sodium silicate solution and potassium aluminum sulfate solution were investigated by Box-Wilson experimental design, and the micromeritic properties were examined by the means of BET $N_2$ adsorption, Hg penetrometer and methylen blue adsorption. The chemical composition of the samples were analyzed by gravitic method. The results were found to be as follows: optimum reaction temperature $54.7^{\circ}C$, both concentrations of reactant soln 15.7%, reactants molar ratio (Al/Si) 0.5 and drying temperature $65.0^{\circ}C$. The acid consuming capacity of the sample prepared by above optimum conditions was 68 ml and the chemical composition was $Al_2O_3{\cdot}3.6SiO_2{\cdot}3H_2O$. The relationship between acid consuming capacity and micromeritic properties could not found in the range of experiments. Therefore, it is assumed that the acid consuming mechanism of aluminum silicate depends on the neutralization of $Al_2O_3$ and buffer action of $SiO_2$ in sample.

• Environmental Engineering Research
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• v.19 no.3
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• pp.289-292
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• 2014

The effect of carbon dioxide ($CO_2$) on global warming is serious problem. The adsorption with solid sorbents is one of the most appropriate options. In this study, the most interesting adsorbent is granular activated carbon (GAC). It is suitable material for $CO_2$ adsorption because of its simple availability, many specific surface area, and low-cost material. Afterwards, GAC was impregnated with chitosan solution as impregnated granular activated carbon (CGAC) in order to improve the adsorption capacity of GAC. This research aims to compare the physical and chemical characteristics of GAC and CGAC. The experiment was carried out to evaluate the efficiency of $CO_2$ adsorption between GAC and CGAC. The results indicated that the iodine number of GAC and CGAC was 137.17 and 120.30 mg/g, respectively. The Brunauer-Emmett-Teller results (BET) of both GAC and CGAC show that specific surface area was 301.9 and $531.3m^2/g$, respectively; total pore volume was 0.16 and $0.29cm^3/g$, respectively; and mean diameter of pore was 2.18 and 2.15 nm, respectively. Finally, the $CO_2$ adsorption results of both GAC and CGAC in single column how the maximum adsorption capacity was 0.17 and 0.25 mol/kg, respectively; how degeneration time was 49.6 and 80.0 min, respectively; and how the highest efficiency of $CO_2$ adsorption was 91.92% and 91.19%, respectively.

• Journal of Environmental Science International
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• v.29 no.12
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• pp.1261-1274
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• 2020

The characteristics of ammonia-nitrogen (NH4+-N) adsorption by a zeolitic material synthesized from Jeju scoria using the fusion and hydrothermal method was studied. The synthetic zeolitic material (Z-SA) was identified as a Na-A zeolite by X-ray diffraction, X-ray fluorescence analysis and scanning electron microscopy images. The adsorption of NH4+-N using Jeju scoria and different types of zeolite such as the Z-SA, natural zeolite, and commercial pure zeolite (Na-A zeolite, Z-CS) was compared. The equilibrium of NH4+-N adsorption was reached within 30 min for Z-SA and Z-CS, and after 60 min for Jeju scoria and natural zeolite. The adsorption capacity of NH4+-N increased with approaching to neutral when pH was in the range of 3-7, but decreased above 7. The removal efficiency of NH4+-N increased with increasing Z-SA dosage, however, its adsorption capacity decreased. For initial NH4+-N concentrations of 10-200 mg/L at pH 7, the adsorption rate of NH4+-N was well described by the pseudo second-order kinetic model than the pseudo first-order kinetic model. The adsorption isotherm was well fitted by the Langmuir model. The maximum uptake of NH4+-N obtained from the Langmuir model decreased in the order of Z-CS (46.8 mg/g) > Z-SA (31.3 mg/g) > natural zeolite (5.6 mg/g) > Jeju scoria (0.2 mg/g).

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1132-1138
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• 2008

The study was carried out to investigate adsorption characteristic on hydrogen sulfide (H$_2$S) and methylmercaptan (CH$_3$SH) odor gas using the char made by a thermal decomposition of sewage sludge. The fixed bed adsorption experiments of the optimum L/D ratio could be 1.0, and adsorption capacity and break point increased with the increase of temperature. A simultaneous adsorption characteristic of H$_2$S and CH$_3$SH increased in breakthrough time and adsorption capacity more than single adsorption experiment, and CH$_3$SH had higher effective diffusivities than H$_2$S in same condition. The adsorption capacity of CH$_3$SH increased with fast velocity. When it was compared the produced absorbent with commercial activated carbon, As to adsorbent amount, it was H$_2$S 77% and CH$_3$SH 80% of commercial activated carbon.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1011-1016
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• 2010

The $H_2S$ adsorption characteristics and property analyses of granular activated carbon adsorbent impregnated with basic solution such as NaOH, KOH, and $(CH_2CH_2OH)_2NH$ were investigated. The concentrations of NaOH and KOH reagent ranged over 1 to 5 M, The concentration of $(CH_2CH_2OH)_2NH$ was in the range of 0.1 to 1 M. Adsorption temperature($25{\sim}45^{\circ}C$) and adsorbate ($H_2S$) concentration (18.23 mg/L) were applied. The experimental results showed that the BET surface area of activated carbon impregnated with KOH decreases from $1,050\;m^2/g$ to $750\;m^2/g$, and the acidity of activated carbon impregnated with NaOH decreases from 0.541 meq/g-AC to 0 meq/g-AC, as the concentration of basic solution increases, while the pH of impregnated activated carbon increased from 9.54 to 10.94 for three basic solutions. It was also found that the $H_2S$ adsorption equilibrium capacity of activated carbon impregnated with NaOH, KOH, $(CH_2CH_2OH)_2NH$ increased with increasing temperature and $H_2S$ adsorption equilibrium capacity of the activated carbon impregnated with diethanolamine was much higher than other cases. At adsorption temperature of $45^{\circ}C$, the $H_2S$ adsorption equilibrium capacity of impregnated activated carbon was 2.0~3.3 times lager than that of pure activated carbon.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.246-252
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• 2015

In steel factory, hot roller cleaning process produces a lot of iron oxide particles called as mill scale. Major components of these particles are wustite (FeO), magnetite ($Fe_3O_4$), and hematite ($Fe_2O_3$). In this study, we tried to produce pure magnetite from the mill scale because of the largest phosphate adsorption capacity of the magnetite. The mill scale was treated with acid (HCl+$H_2O_2$), base (NaOH), and acid-base ($H_2SO_4$+NaOH). Batch adsorption tests showed the acid and/or base treatment could increase the phosphate adsorption capacity of the iron oxides from 0.28 to over 3.11 mgP/g. Magnetite, which could be obtained by acid and base treatment of the mill scale, showed the best adsorption capacity. From the kinetic analysis, both Freundlich and Langmuir isotherm well described the phosphate adsorption behavior of the magnetite. In Langmuir model, maximum phosphate adsorption capacity was found to be 5.1 mgP/g at $20^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.371-377
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• 2004

Sulfate adsorption in forest soils is a process of sulfur dynamics playing an important role in plant uptake, cation movement, acid neutralization capacity and so on. The relationship between sulfate adsorption and some physicochemical properties of four forest soils was investigated. Extractable sulfate contents and sulfate adsorption capacity (SAC) in the forest soils varied much among study sites. Extractable sulfate contents were more in sub-surface soils with lower organic matter and greater Al and Fe oxides than in surface soils. The average contents of $Al_d$ and $Fe_d$ in the sub-surface soils were 8.49 and $12.45g\;kg^{-1}$, respectively. Soil pH, cation exchange capacity and clay content were positively correlated with the extractable sulfate contents and SAC. Organic carbon content, however, was negatively correlated with the extractable sulfate contents, implying the competitive adsorption of sulfate with soil organic matter. Considerably significant correlation was found between inorganic + amorphous Al and Fe oxides and the sulfate adsorption, but crystalline Al and other fractions of Fe oxide showed no correlation. Relatively close relationship between the adsorbed sulfates and soil pH, cation exchange capacity, or amorphous Al oxides indicates that the accelerated soil acidification may substantially reduce the potential for sulfate adsorption contributing to sulfur flux in forest ecosystems.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.202-209
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• 2022

Effects of the support and amount of NiCl₂ on ammonia adsorption capacity were investigated to improve the ammonia adsorption performance. NiCl₂ was impregnated onto the surface of various supports under ultrasonic irradiation. The physicochemical properties and ammonia adsorption performance of NiCl₂-impregnated adsorbents were investigated. Among the various supports, it was found that the adsorption capacity of ammonia was the best when NiCl₂ was impregnated on activated carbon (AC) with the highest specific surface area. As a result of changing the amount of NiCl₂ impregnated on AC, the NiCl₂(2.0)/AC adsorbent impregnated with 2 mmol·g^-1 of NiCl₂ showed the highest ammonia adsorption capacity of 5.977 mmol·g^-1. In addition, the adsorption capacity was found to be maintained at an almost constant level in five repeated cycle tests under the condition that low-temperature heat could be utilized. This indicates that the adsorbent has excellent regeneration ability.