• 대한안전경영과학회지
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• 제16권2호
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• pp.231-236
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• 2014

In this study, the changes in collection efficiencies due to the time changes of activated carbons were ascertained, and in order to identify the magnitude of adsorption, the before-use and after-use iodine adsorption values were analyzed. In addition, as a result of examining the characteristics of continuous process and non-continuous process and as a result of investigating whether the emission standards would be maintained, the continuous process and printing facilities were seen as not being able to maintain the emission standards. Also were found, in the case of non-continuous process,-taking into consideration the special nature of the job -for 4${\o}$ palletized charcoal, a collection efficiency near 50% was shown even after 96 hours. Also, when the inlet concentration was about 300ppm, it is thought that the emission standards would be maintained if the activated carbons are replaced within at least 96 hours in the case of 4${\o}$ palletized charcoal and the use was deemed pointless in the case of carbon. The results of this study are expected to provide assistance in selecting replacement periods for activated carbons and in selecting absorbents at the project sites, and are expected to be of significant help in the selection of precipitators that can collect total hydrocarbons for compliance of the emission standards.

• 한국환경과학회지
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• 제21권10호
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• pp.1195-1202
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• 2012

The purpose of this work is to study the adsorption and desorption characteristics of acetone vapor and toluene vapor from adsorption tower in the VOCs recovery device. The six kinds of activated carbon with different pore structures were used and the adsorption and desorption characteristics were compared according to pore structure, desorption temperature, and adsorption method, respectively. Adsorption capacity of acetone vapor and toluene vapor by batch method was higher than that by dynamic method. Especially, activated carbon with medium-sized or large pores had more difference in adsorption capacity according to adsorption methods as a result of gradually condensation of vapors on relatively mesopore and large pores. Activated carbons with relatively large pores and relatively small saturated adsorption capacity had excellent desorption ability.

• 공업화학
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• 제33권2호
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• pp.133-144
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• 2022

Fast-paced industrial and agricultural development generates large quantities of hazardous heavy metals (HMs), which are extremely damaging to individuals and the environment. Research in both academia and industry has been spurred by the need for HMs to be removed from water bodies. Advanced materials are being developed to replace existing water purification technologies or to introduce cutting-edge solutions that solve challenges such as cost efficacy, easy production, diverse metal removal, and regenerability. Water treatment industries are increasingly interested in activated carbon because of its high adsorption capacity for HMs adsorption. Furthermore, because of its huge surface area, abundant functional groups on surface, and optimal pore diameter, the modified activated carbon has the potential to be used as an efficient adsorbent. Metal-organic frameworks (MOFs), a novel organic-inorganic hybrid porous materials, sparked an interest in the elimination of HMs via adsorption. This is due to the their highly porous nature, large surface area, abundance of exposed adsorptive sites, and post-synthetic modification (PSM) ability. This review introduces PSM methods for MOFs, chemical modification of activated carbons (ACs), and current advancements in the elimination of Pb²⁺, Hg²⁺, and Cd²⁺ ions from water using modified MOFs and ACs via adsorption.

• Carbon letters
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• 제1권3_4호
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• pp.178-190
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• 2001

• Composites Research
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• 제31권2호
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• pp.76-81
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• 2018

In this study, the elemental mercury removal behaviors of silver-plated porous carbons materials were investigated. The pore structures and total pore volumes of the hybrid materials were analyzed by $N_2$ adsorption/desorption analysis at 77 K. The pore structures and surface morphologies of the hybrid materials were characterized by XRD and SEM, respectively. The elemental mercury adsorption capacities of all silver-plated porous carbons hybrid materials were higher than those of the as-received samples, despite the fact that the specific surface areas and total pore volumes decreased with increasing metal loading time. It was found that silver nanoparticles showed excellent elemental mercury removal behaviors in carbonaceous hybrid materials.

• Carbon letters
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• 제8권1호
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• pp.17-24
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• 2007

Microporous carbons with narrow pore size distribution have been successfully synthesized by using hydrolyzed and calcined silica as templates and phenol formaldehyde (pf) resin as carbon precursor. Phenol formaldehyde-silica micro composites were prepared by solution route. Subsesequently, silica templates were removed by HF leaching. Resulting carbons were steam activated. The porous carbons were characterized by nitrogen adsorption-desorption isotherm, SEM, FTIR analysis, iodine adsorption, thermogravimetry analysis, etc. Adsorption isotherms show that the porous carbon prepared from calcined silica as templates are microporous with 88% pores of size <2 nm porosity and are of type I isotherm, while porous carbon prepared by using hydrolyzed silica are microporous with 89% microporosity, shows hysteresis loop at high relative pressure indicating the presence of some mesoporosity in samples. The microporosity in porous carbon materials has a bearing on the nature of silica templates used for pore formation.

• Carbon letters
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• 제17권1호
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• pp.85-89
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• 2016

• 한국대기환경학회지
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• 제29권3호
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• pp.317-324
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• 2013

This research assessed the surface properties of modified activated carbons with three different acids and five different metals for ammonia gas removal. Raw bituminous coal-based activated carbon ($4{\times}8$ mesh) had low adsorption capacity of 0.72 mg $NH_3/g$ based on the analysis in the column adsorption experiment. Adsorption capacities of carbons modified with $CH_3COOH$, $H_3PO_4$, and $H_2SO_4$ increased up to 3.34, 21.00, and 35.21 mg $NH_3/g$, respectively. Those of carbons with Cu, Zn, Zr, Fe, and Sn were 9.63, 9.13, 7.09, 25.12 and 15.03 mg $NH_3/g$. Ammonia adsorption was enhanced by the presence of surface oxygen groups on carbon materials, which influenced pH of carbon surface. BET surface area of raw carbon was analyzed to be $1087m^2/g$, but it decreased by carbon surface modification. Fe-impregnated carbon showed $503.02m^2/g$ of surface area. These observations were mostly caused by chemical adsorption.

• 대한환경공학회지
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• 제30권2호
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• pp.218-224
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• 2008

본 연구에서는 석탄계, 야자계, 목탄계 활성탄과 흡착능이 없는 안트라사이트를 이용하여 클로랄하이드레이트에 대한 흡착 및 생물분해 특성을 평가하였다. 활성탄 공정에서 클로랄하이드레이트의 제거기작은 운전초기에는 흡착이 높은 비중을 차지하나 부착미생물의 활성이 증진되면서 부착미생물에 의한 생분해와 흡착에 의해 제거되었으며, 클로랄하이드레이트는 생분해능이 큰 물질들로 조사되었다. 입상활성탄 재질별 클로랄하이드레이트의 제거 특성은 석탄계와 야자계 활성탄에서 제거율이 높았고, 목탄계는 상대적으로 낮은 제거능을 보였으며, 안트라사이트 biofilter에서 가장 낮은 제거능을 보였다. 활성탄 재질별 부착 미생물의 생체량과 활성도는 석탄계가 가장 높았고, 야자계, 목탄계, 안트라사이트 순으로 나타났으며, 수온 변화에 따른 클로랄하이드레이트의 제거 특성은 수온이 10$^{\circ}C$ 이하로 저하될 경우 부착 bacteria의 생체량과 활성도 감소로 제거율이 감소하였다. 안트라사이트를 이용한 생물여과 공정은 수온의 변화에 아주 민감하게 변하는 양상을 나타내었으며, 이는 부착 bacteria에 의한 직접적인 생물분해가 주 제거 메카니즘이기 때문인 것으로 나타났다. 클로랄하이드레이트의 제거시 유입농도가 높은 경우에는 수온의 영향이 매우 중요하며, 흡착능이 소진된 활성탄이나 흡착능이 없는 여재를 사용한 생물여과 공정에서는 수온이 낮은 동절기에는 클로랄하이드레이트의 유출 가능성이 있었다.

• Carbon letters
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• 제11권3호
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• pp.192-200
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• 2010

Common reed (Fragmites australis), a local invasive grass, was investigated as a possible feedstock for the production of activated carbon. Dried crushed stems were subjected to impregnation with phosphoric acid (30, 40 and 50%) followed by pyrolysis at $400{\sim}500^{\circ}C$ with final washing and drying. Obtained carbons were characterized by determining: carbon yield, ash content, slurry pH, textural properties and capacity to remove color bodies from factory-grade sugar liquor. Produced carbons possessed surface area up to 700 $m^2/g$, total pore volumes up to 0.37 $cm^3/g$, and proved to be microporous in nature. Decolorization of hot sugar liquor at $80^{\circ}C$ showed degrees of color removal of 60 up to 77% from initial color of 1100~1300 ICU, at a carbon dose of 1.0 g/100 ml liquor. No correlation seems to hold between synthesis conditions and % R but depends on the degree of microporosity. A commercial activated carbon N showed a comparative better color removal capacity of 91%. Common reed proved to be a viable carbon precursor for production of good adsorbing carbon suitable for decolorization in the sugar industry, as well as in other environmental remediation processes.