• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.533-540
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• 2010

An activated carbon was tested for its ability to remove transition metal ions from aqueous solutions. Physical, chemical and liquid-phase adsorption characterizations of the carbon were done following standard procedures. Studies on the removal of Ni(II), Cu(II) and Fe(III) ions were attempted by varying adsorbate dose, pH of the metal ion solution and time in batch mode. The equilibrium adsorption data were fitted with Freundlich and Langmuir and the isotherm constants were evaluated, equilibrium time of the different three metal ions were determined. pH was found to have a significant role to play in the adsorption. The processes were endothermic and the thermodynamic parameters were evaluated. Desorption studies indicate that ion-exchange mechanism is operating.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.87-97
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• 2018

The cesium (Cs) removal from the contaminated water system has been considered to be difficult because the cesium likes to exist as soluble phases such as ion and complexes than the solid in water system. Many researches have focused on developing the breakthrough adsorbent to increase the cesium removal efficiency in water. In this study, the laboratory scale experiments were performed to investigate the feasibility of the adsorption process using the bamboo charcoal for the Cs contaminated water system. The Cs removal efficiency of the bamboo charcoal were measured and the optimal adsorption conditions were determined by the adsorption batch experiments. Total 5 types of commercialized bamboo charcoals in Korea were used to identify their surface properties from SEM-EDS and XRD analyses and 3 types of bamboo charcoals having large specific surface areas were used for the adsorption batch experiment. The batch experiments to calculate the Cs removal efficiency were performed at conditions of various Cs concentration (0.01 - 10 mg/L), pH (3 - 11), temperature ($5-30^{\circ}C$), and adsorption time (10 - 120 min.). Experimental results were fitted to the Langmuir adsorption isotherm curve and their adsorption constants were determined to understand the adsorption properties of bamboo charcoal for Cs contaminated water system. From results of SEM-EDS analyses, the surfaces of bamboo charcoal particles were composed of typical fiber structures having various pores and dense lamella structures in supporting major adsorption spaces for Cs. From results of adsorption batch experiments, the Cs-133 removal efficiency of C type bamboo charcoal was the highest among those of 3 bamboo charcoal types and it was higher than 75 % (maximum of 82 %) even when the initial Cs concentration in water was lower than 1.0 mg/L, suggesting that the adsorption process using the bamboo charcoal has a great potential to remove Cs from the genuine Cs contaminated water, of which Cs concentration is low (< 1.0 mg/L) in general. The high Cs removal efficiency of bamboo charcoal was maintained in a relatively wide range of temperatures and pHs, supporting that the usage of the bamboo charcoal is feasible for various types of water. Experimental results were similar to the Langmuir adsorption model and the maximum amount of Cs adsorption (qm:mg/g) was 63.4 mg/g, which was higher than those of commercialized adsorbents used in previous studies. The surface coverage (${\theta}$) of bamboo charcoal was also maintained in low when the Cs concentration in water was < 1.0 mg/L, investigating that the Cs contaminated water can be remediated up with a small amount of bamboo charcoal.

• Resources Recycling
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• v.31 no.4
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• pp.49-55
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• 2022

In this study, the heavy metal ions (of Pb, Cd, Cr, and Hg) in wastewater were removed using a spent Li₂O-Al₂O₃-SiO₂-based crystallized glass previously used as an induction top plate material. Changes in the removal efficiency of heavy metals according to different reaction parameters, such as the amount of zeolite used as a heavy-metal adsorbent, adsorption time, initial concentration of the heavy metals, and pH of the initial solution, were investigated. As the amount of zeolite added increased, the heavy-metal removal efficiency also increased. Adsorption time had a considerable influence on adsorption characteristics, and the removal efficiency of all heavy metals increased with increasing adsorption time. In the case of Cd, the removal efficiency was greatly improved depending on the adsorption time. The initial concentration of the heavy-metal solution did not affect the removal efficiency; however, the initial pH of the heavy-metal solution affected the removal efficiency. More specifically, the removal efficiency of Cd increased while that of Pb and Cr decreased with increasing pH. The adsorption characteristics of Hg were not significantly affected by pH.

• Resources Recycling
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• v.19 no.2
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• pp.28-34
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• 2010

In this study, cow tibial from cow bone, a kind of beef waste, sintered at $800\sim850^{\circ}C$ for three hours was used to measure its removal capacity for metal ions such as Pb, Cd and Zn in a single and a multi-component equilibrium systems. The sorption equilibrium data were analyzed as measured by the effect of media on lead, cadmium and zinc sorption. This analysis shows that the sorption of metal ions for multi-component systems applying IAST can be predicted more reasonably by the Freundlich and the Sips theory than the Langmuir.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.571-580
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• 2018

In this study, hybrid adsorbents (SS) were prepared by mixing spent coffee grounds (SCG) and sericite, a kind of clay minerals, to adsorb Pb(II) from an aqueous solution. In FT-IR analyses, the main functional groups of SS adsorbents were O-H, C=O and C-N groups. The specific surface area, cation exchange capacity and the pore diameter of SS were larger than those of using SCG and sericite. Formation conditions of the SS adsorbent were the optimum pyrolysis temperature of $300^{\circ}C$, SCG : sericite ratio of 8 : 2, and particle size of 0.3 mm. Langmuir adsorption isotherm was more suitable than Freundlich one, and the maximum adsorption capacity was reached 44.42 mg/g. As a result of the adsorption thermodynamic analysis, the adsorption of Pb(II) onto SS was the physical adsorption and exothermic process in nature. The regeneration of SS adsorbent using distilled water showed 88~92% recovery and the active site of SS adsorbent decreased with increasing the reuse cycle time. As a result, SS adsorbent showed that it can be used to remove Pb(II) easily, inexpensively and efficiently without any pre-treatment from aqueous solutions.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.83-87
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• 2012

Activated carbon fiber (ACF) was used to remove four kinds of trihalomethanes(THMs) from tap water which were remained as by-products during the chlorination of water. Adsorption capacity was investigated as a function of THMs concentration and solution temperature, and adsorption mechanism was studied in relating to the surface characteristics of ACF. All the four kinds of THMs were rapidly adsorbed on the surface of ACF by physical adsorption due to the enormous surface micropores and chemical adsorption due to the hydrogen bonds, showing a Langmuir type adsorption isotherm. Langmuir type is especially profitable for the adsorption of low level adsorptives. ACF was very effective for the removal of THMs from tap water because the THMs concentration is below $30{\mu}g/L$ in tap water. The adsorption amount of THMs on ACF increased in order of the number of brom atom; chloroform, bromodichloromethane, dibromochloromethane, and bromoform. The adsorption capacity increased as increasing the number of brom atom due to the decrease of polarity in solution. The adsorption capacity of THMs on ACF can be enhanced by proper surface treatment of ACF.

• 수도
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• v.23 no.6 s.81
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• pp.30-35
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• 1996

조류의 성장에 기인하여 대청호로부터 발생된 이취미와 천연유기물질의 제거를 위해 활성탄 흡착에 관한 파일롯 플랜트연구를 수행하였다. 대청호원수의 용존유기물질 농도는 1.5-3.5mg/1으로 나타났고, 이취미를 유발시킨 주 성분인 Geosmin농도는 가을에 60ng/1 이상이 검출되었다. 이는 8월말부터 발생하기 시작하여 10월말 까지 지속되었다. 이는 8월말부터 발생하기 시작하여 10월말 까지 지속되었다. 한국수자원공사 대청수도내 파일롯 플랜트는 재래식정수처리 시스템에 오존산화공정, 4개의 입상활성탄 흡착탑으로 구성되었다. 공탑체류시간(EBCT) 15분 이상에서, 이취미 발생기간동안 GAC 3지와 4지에서 이취미는 완전히 제거되었다. 활성탄 원료 종류별 DOC제거를 위한 파일롯연구에서 석탄계 활성탄으로 충진한 GAC 3지와 4지는 운전 3개월 후에 파괴되기 시작하였고, 이 후 4개월의 운전동안 약 40-50%의 일정한 제거효율을 보여주었다. 야자계 활성탄으로 충진된 GAC 2지는 2개월의 운전 후에 완전히 파괴되었다.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.309-312
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• 2006

최근에는 산업의 발전에 따라 다종 다양한 형태의 중금속이 이용되고 있지만 처리공정의 효율상의 한계성 때문에 미량의 중금속이 배출되어 생태계의 치명적인 위협요소로 부각되고 있다. 중금속이 포함된 폐수는 일반적으로 여러 가지 방법이 있지만 생체물질을 이용한 생체흡착에 대한 연구 및 공정 개발이 활발히 이루어지고 있다. 생체흡착은 중금속이 생물체 표면이나 내부로 물리 화학 및 생물학적 상호작용에 의한 이온교환, 흡착등 다양한 기작에 의해 수용액으로부터 중금속이 제거되는 것이다. 본 연구에서 바실러스에 의한 EPS 물질을 추출하였으며 포자화 전과 후의 EPS를 이용하여 중금속제거 실험을 하였다. EPS 물질은 Protein이 Carbohydrate보다 많은 함량을 보였으며 중금속 제거는 포자화 전보다 포자화 후의 EPS가 더 많이 제거되는 것으로 나타났다.

• Analytical Science and Technology
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• v.13 no.1
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• pp.96-100
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• 2000

The adsorption of heavy-elements to zeolite has been investigated at various adsorptional condition for purification of waste water. Four heavy elements, Cd, Cr, Cu and Pb, were examined, because they are concerned to the major heavy-element contamination. The adsorption efficiencies are measured at the different conditions such as adsorption times and pHs. The practical adsorption was achived and reaches to maximum within 30 minute by using of 2-g zeolite for 50 mL of heavy-element solution. The overall adsorption efficiencies for Cr and Cu are high and become better at low pH. Cd and Pb have 95% of adsorption ratio and this is lower than other two elements. Cadmium shows an abnormally low adsorption at low pH.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.259-264
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• 1994

Heparin binders (Cell-PALA) used for selective heparin removal from blood, were prepared by immobilizing a cationic polymer, poly(allylamine) (PALA), onto cellulose substrate by a novel method. Their absorbing capacity for heparin was compared with untreated cellulose control using heparin solution in vitro. The surface areas of obtained heparin binders and untreated cellulose were 1.36 and ($2.56{\mu} g$/$cm^2$, respectively. The amount of bound heparin to PALA immobilized celluloses was determined to be 0.16 - $0.30{\mu}g$/cm, which is much higher than that of untreated cellulose ($0.03{\mu} g$/$cm^2$). These results suggest that Cell-PALA materials can be utilized for a heparin removal system.