• 대한환경공학회지
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• 제35권5호
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• pp.307-311
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• 2013

대기 중 $CO_2$ 포집 기술은 비점오염원 배출 $CO_2$를 포집할 수 있는 유일한 기술 중 하나이다. 본 논문에서는 저농도 $CO_2$를 이용한 흡착 실험을 수행하였다. 세 종류의 흡착제를 이용한 흡착과 열재생을 반복하는 실험을 수행한 결과 제올라이트 5A, 13X 그리고 활성탄의 $CO_2$ 흡착량은 21 mg/g, 12 mg/g 그리고 6 mg/g으로 나타났으며, 열재생 반복실험 결과에서 제올라이트 5A가 가장 우수한 흡착 성능을 보여주었다.

• 한국대기환경학회지
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• 제17권1호
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• pp.67-74
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• 2001

In the manufacturing process of PCB , three kinds of VOCs such as aceton, methanol and 2-metoxyethanol are being used. In this study, adsorption characteristics of activated carbon fibers(ACFs) and active carbon were examined to temove these VOCs. The experimental results showed that ACF has better adsorption and regeneration efficiency than activated carbon. Phenolic-resin based ACF showed the highest adsorption capacity and the capacity was not decreased after repeated regeneration by steam. On the adsorption and desorption experiments for ternary components, preferential adsorption with roll-over phenomena was appeared. 2-Metoxyethanol was strong adsorbaste and it displaced adsorbed methanol and aceton.

• 한국응용과학기술학회지
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• 제20권1호
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• pp.72-79
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• 2003

The impregnated activated carbons were prepared by the incipient wetness method with the contents of $KIO_3$ varied from 1.0${\sim}$10 wt% as the impregnation material. The specific surface area and micropore volume of the rice hulls activated carbon were $2,600{\sim}2,800$ $m^2$/g and 1.1${\sim}$1.4 cc/g, respectively. With increasing the contents of impregnation materials, the surface area and micropore volume decreased by 3${\sim}$21%. However, The amounts of hydrogen sulfide adsorbed increased by 2.1${\sim}$2.8 times depending on the impregnation content. The optimum contents of $KIO_3$ were 2.4 wt%. Although the breakthrough time and adsorption capacity of hydrogen sulfide decreased with increasing temperature in the case of the unimpregnated activated carbons, they increased by 1.2${\sim}$ 3.2 times for the case of the impregnated activated carbons. The optimum aspect ratio(L/D) was 1.0 and the adsorption amount of hydrogen sulfide enhanced with increasing the gas flow rate. The regeneration temperature was determined as 400$^{\circ}C$ from the TGA experiment. The adsorption capacity of hydrogen sulfide with the impregnated activated carbon decreased gradually as the regeneration continued. The hydrogen sulfide adsorption amount of the regenerated activated carbon up to 4 times was still higher than that of the unimpregnated activated carbon.

• 한국환경과학회지
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• 제24권9호
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• pp.1163-1170
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• 2015

This study carried out continuous column test for estimating the regeneration efficiency with regeneration times and temperatures. More times regenerated granular activated carbon (GAC) has more ash in the GAC and has less apparent density. Two times regenerated GAC ($2^{nd}$ re-GAC) could removed the Trihalomethanes (THMs) in the water for the first two week after starting continuous column test, on the other hand five times regenerated GAC ($5^{th}$ re-GAC) did not have adsorption capacity. The THMs concentration in the effluent was almost equal or higher than that of influent at the first time of continuous column test. $2^{nd}$ re-GAC showed much more DOC adsorption capacity than $5^{th}$ re-GAC and the GAC which was regenerated with $700^{\circ}C$ had highest DOC removal efficiency among the GACs with 600, 700, 800, $900^{\circ}C$ regeneration temperatures. It is anticipated the cost of GAC regeneration could be saved more 100 million won by reducing the furnace temperature of 3rd~4th and 5th~6th about $150^{\circ}C$ compared to the current regeneration condition.

• Carbon letters
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• 제3권4호
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• pp.205-209
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• 2002

In the reaction of gas-solid phases, the microwave energy plays a role as a catalyst, because it causes friction between adjacent molecules and enables an unique characteristics of interior heating of the materials. When the dipole gases are adsorbed inside of the pore of carbon materials, the gases are decomposed by the microwave energy and reacted with the carbon atoms. Using this principle, we could make the activated carbon from coconut shell within 20 minute, and this residence time for activation is about 1/16 of rotary kiln. The BET surface area of activated carbon made by microwave is about $1,100m^2/g$ similar to conventional method of rotary kiln. In this study, the power of microwave generator was 400~1000W, and the gas for activation was steam mainly.

• Carbon letters
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• 제8권2호
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• pp.101-107
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• 2007

Activated carbons were prepared by impregnation of crushed clean date pits in concentrated solutions of phosphoric acid or zinc chloride followed by carbonization in absence of air at $600^{\circ}C$. Steam-activated carbon was prepared by gasifying $600^{\circ}C$-carbonization product at $950^{\circ}C$ to a burn-off = 50%. KOH- activated carbon was prepared by impregnating date pitscarbonization product obtained at $450^{\circ}C$ in concentrated KOH solution followed by carbonization at $840^{\circ}C$. Textural properties of these carbons were determined from nitrogen adsorption at $-196^{\circ}C$ and the chemistry of the carbon surface was investigated by determination and of the surface carbon-oxygen (C-O) groups using bases of variable strength and dilute HCl. The adsorption of endosulphan at $27^{\circ}C$ on all the carbons prepared was undertaken. Adsorption of this pesticide at 32 and $37^{\circ}C$ was also undertaken for steam-activated and KOH-activated carbons. Phosphoric acid-activated carbons and steamactivated carbons are mainly microporous and have high surface concentration of C-O groups of acidic nature. Steamactivated and KOH-activated carbons exhibited surface areas > 1000 $m^2/g$ and contain micro and non-micrpores. The adsorption of endosulphan was related to the surface area of non-micropores and was retarded by the high concentration of surface C-O groups. The thermodynamic properties indicated the feasibility of the adsorption process and the possible regeneration of the carbon for further use.

• 한국환경보건학회지
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• 제27권1호
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• pp.63-68
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• 2001

A laboratory experiment was performed to invstigate the nitrate removal using FeCl$_3$ -treated activated carbon. Iron chloride(III) was coated onto the surface of activated carbon. The removal efficiency of nitrate was increased with increasing of FeCl$_3$ was used for coating material. About 22~26mg of Fe per unit g of activated carbon was adsorbed. The nitrate removal was not affected by the pH under the experiment range of pH, but the pH value in solution decrease to 3.5~4.0 after reaction. The removal efficiency of nitrate was increased with increasing of dosage of adsorbents. Ammonia was not detected and the Fe concentration as low as 0.22mg/$\ell$ was desorbed from the adsorbents. The adsorbents was regenerated using KCl solution, and recovery was 76.6% at 1 M of KCl. The adsorption of nitrate by FeCl$_3$-treated activated carbon followed the Freundlich isotherm equation and the Freundlich constant, 1/n, was 0.346. These results showed that the FeCl$_3$-treated activated carbon could serve as the basis of a useful nitrate removal.

• 상하수도학회지
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• 제36권2호
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• pp.121-134
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• 2022

In this study, the removal efficiency of PFCs(perfluorinated compounds) in the GAC(granule activated carbon) process based on the superheated steam automatic regeneration system was investigated in laboratory scale and pilot-scale reactor. Among PFCs, PFHxS(perfluorohexyl sulfonate) was most effectively removed. The removal efficiency of PFCs was found to be closely related to the EBCT, and the removal efficiencies of PFOA(perfluorooctanoic acid), PFOS(perfluorooctyl sulfonate), and PFHxS were 43.7, 75, and 100%, respectively, under the condition of EBCT of 6 min. Afterward, PFOA, PFOS, and PFHxS exhibited the earlier breakthrough time in the order. After that, GAC was regenerated, and the removal efficiency of the PFCs before and after regeneration was compared. As a result, it was shown that the PFCs removal efficiency in the regenerated GAC process were higher, and that of PFOA was improved to 75%. The findings of this study indicate the feasibility of the superheated steam automatic regeneration system for the stable removal of the PFCs, and it was verified that this technology can be applied stably enough even in field conditions.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2468-2473
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• 2018

Nitrogen-doped activated carbon fibers (ACFs) were prepared by chemical vapor deposition using melamine powder and acetonitrile for introducing quaternary nitrogen on the commercial ACFs, subsequently heated at $950^{\circ}C$ and activated by steam. Adsorption experiments of nitrate in aqueous solution were also conducted to evaluate adsorption capacity of the prepared ACFs using ion chromatography. The amount of introduced nitrogen content and nitrogen species on activated carbon fibers was examined by CHN elemental analyzer and X-ray photoelectron spectroscopy, respectively. As a result, adsorption capacity of quaternary nitrogen-doped ACF (ST-ML-AN-ST) was 0.75 mmol/g, indicating ca. two-times higher than that of untreated ACF (0.38 mmol/g). According to the adsorption data, the Langmuir isotherm model was the best fit. The prepared samples were also regenerated using hydrochloric acid. After regeneration, the adsorption capacity of the nitrogen-doped ACF (ST-ML-AN-ST) showed ca. 80% on average, implying that a portion of nitrates was adsorbed on the prepared ACFs irreversibly.

• Plant Resources
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• 제8권3호
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• pp.275-280
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• 2005

Tissue culture systems to optimize regeneration plant species of Ocimum spp were evaluated as a method to micropropagate individual plants and to better study their biology in vitro. Ocimum species were also evaluated for the production of natural plant products during and following the regeneration process. The primary goal of this project was to enhance the regeneration efficiency of basil. Several factors were examined using different Ocimum species and commercial varieties. The effect of cytokinin combination, activated charcoal, gelling agents, and different carbon sources were investigated. Anthocyanin callus spots were produced only in four varieties among six tested. 'Sweet Dani' showed the best results on anthocyanin accumulation, while 'African beauty', 'Tree basil' and 'Methylcinnamate' produced only a few spots. Shoot regeneration was only achieved from 'Sweet Dani' explants. As the activated charcoal concentration increased, callus formation rate decreased respectively compare to the controls for all varieties. There was a decrease in callus growth with increasing concentration of agar and phytagel.