• Journal of Environmental Health Sciences
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• v.14 no.2
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• pp.65-71
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• 1988

In this study, the method of adsorption by activated carbon in the removal of Hg(II) ion in waste water was treated. The influence of kinds of activated carbon and effect of temperature and the influence of coexistent salt on adsorption rates, the influence of pH in the adsorption, equilibrium and adsorption of mercury from activated carbon were investigated. From the adsorption on activated carbon of mercury(II) ion in the presence of cyanide or thiocyanate ion was found that mercury(II) was easily adsorved onto the activated carbon in the form of complex artion such as Hg(CN)$_4^{2-}$, Hg(SCN)$_4^{2-}$ respectively. ZnCl$_2$ activation method had a higher adsorptive ability than steam activation method in adsorption of Hg on activated carbon. Activated carbon adsorbed iodide ion is very effective on adsorption of Hg.

• Clean Technology
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• v.27 no.2
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• pp.160-167
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• 2021

This study investigated the environmental effects of improving the general-type activated carbon adsorption tower used at the Sihwa/Banwol Industrial Complex with use of a cartridge-type activated carbon adsorption tower for the application of an activated carbon co-regenerated system. Four general-type activated carbon adsorption towers and two cartridge-type activated carbon adsorption towers were selected to analyze the properties of activated carbon and to compare the efficiency of reducing environmental pollutants. The results showed that the activated carbon used in the cartridge-type activated carbon adsorption towers was high quality activated carbon with an iodine adsorption force of more than 800 mg/g and that a good adsorption performance was maintained within the replacement cycle. From an analysis of the environmental pollutant reduction efficiency, it was confirmed that the cartridge-type activated carbon adsorption tower functioned properly as a prevention facility for handling emissions pollutants with a treatment efficiency of total hydrocarbons (THC), toluene, and methylethylketone (MEK) components of 71%, 77%, and 80%, respectively. The general activated carbon adsorption tower, which was confirmed to use low-performance activated carbon, had a very low treatment efficiency and did not function properly as a prevention facility for dealing with emission pollutants. It is believed that it is possible to reduce pollutants during operations by changing from the general-type activated carbon adsorption tower to a cartridge-type activated carbon adsorption tower.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.491-496
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• 2010

This study aimed to obtain equilibrium concentration on adsorption removal of phosphorus by activated carbon, to express the adsorption characteristics following Freundlich isotherm and also, based on the value obtained, to investigate the relationship between physical properties of activated carbon and dynamics of phosphorus removal by obtaining rate constant and effective pore diffusivity. The results summarized from this study are as follows. Phosphorus adsorption equilibrium reaching time of powdered activated carbon was reduced as the dosage of activated carbon increases, while granular activated carbon despite increased dosage did not have influence on adsorption equilibrium reaching times of phosphorus as well, taking more than 10 hours. It was also noted that powdered activated carbon showed better adsorption ability than granular activated carbon. The value of constant (f) of Freundlich isotherm of powered activated carbon on phosphorus was 4.26 which is bigger than those of granular activated carbon. The adsorption rate constant on phosphorus of powered activated carbon with low effective diameter and iodine number was highest as $8.888hr^{-1}$ and the effective pore diffusivity ($D_e$) was lowest as $2.45{\times}10^{-5}cm^2/hr$, and the value of phosphorus adsorption rate constant of granular activated carbon was $0.174{\sim}0.372hr^{-1}$, It was revealed that, with the same amount of dosage, the adsorptive power of activated carbon with lower effective diameter was better and its rate constant was also high.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3377-3381
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• 2011

In this work, the amine grafting treated activated carbons were studied for carbon dioxide adsorbent. The surfaces of activated carbon were functionalized by 3-chloropropyltrimethoxysilane, which was subsequently grafted with amine compounds tris-(2-aminoethyl)amine and tri-ethylenetetramine and subjected to comparison. The surface functional groups of the amine grafted activated carbons were characterized using XPS. The textural properties of the amine grafted activated carbons were analyzed by $N_2$/77 K isotherms. Carbon dioxide adsorption behaviors of the amine grafted activated carbons were examined via the amounts of carbon dioxide adsorption at 298 K and 1.0 atm. From the results, tris-(2-aminoethyl)amine grafted activated carbons showed 43.8 $cm^3$/g of carbon dioxide adsorption while non-treated activated carbons and triethylenetetramine grafted activated carbons showed less carbon dioxide adsorption. These results were thought to be due to the presence of isolated amine groups in the amine compounds. Tris-(2-aminoethyl)amine grafted activated carbons have basic features that result in the enhancement of adsorption capacity of the carbon dioxide molecules, which have an acidic feature.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.54-61
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• 2000

Recently, our circumstances are threatened by an accident that leakage of under ground storage tank and illegal dumping of synthetic organic compounds at chemical plants and many treatment methods, Activated carbon adsorption, Ozonization, Membrane filtration and Photocatalystic oxidation, are developed to remove such a synthetic organic compounds. And it has reported that Activated carbon adsorption have a great removal efficiency to nondegradable matters and organic compounds which have a high molecular weight. Comparing with other adsorbents, Activated carbon adsorption have a worse efficiency when ad desorption speed is low. Thus improved type of adsorbents was invented and one of those is Activated Carbon Filter. The purpose of this study was getting information about adsorption characteristic phenol which can be applied Activated Carbon Fiber and Granular Activated Carbon. In detail, With comparing removal characteristics of phenol in the presence Humic Acid using Activated Carbon Fiber(ACF) and Granular Activated. Carbon(GAC), it is to certify an effective application of Activated Carbon Fiber. At the range of this study, Batch test, Isotherm adsorption test and Factorial analysis, following conclusion were obtained from the results of this study. Batch test was carried to know time of adsorption equilibrium. In this study about time of adsorption equilibrium by ACF was faster than GAC's, for developed micropore of ACF. From the result of phenol adsorption test, High removal rate of adsorption is shown at pH 5. The result of lsotherm adsorption test, it has represented that the Freundlich's isotherm is most suitable one in others, that a ACF's adsorption capacity is more excellent than GAC's. Adsorption of phenol exiting humic acid is decreased getting raised humic acid concentration. Since ACF's micropore is developed at this time, an effect of high molecular humic acid is lower. Factorial analysis was carried to know about Main effect which was injection dosage of adsorbent in the range of this study.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.25-32
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• 1993

Granular activated carbon is commonly used in fixed-bed adsorbers to remove organic chemicals. In this experiment organic chemical solutions were prepared by adding the reagent grade organic chemical to distilled water. Isotherm adsorption tests of volatile organic chemicals were conducted using bottle-point technique and column test. Organic chemicals after passing through the column were extracted with hexane and analyzed with gas chromatography (Hewlett-Packard 5890) to check the adsorption capacity and breakthrough curve. The result were as follows: 1. The BET surface area of coconut activated carbon was 658~1,010 m$^2$/g where as coconut shell carbon was 6.6 m$^2$/g. Coconut activated carbon increased the BET surface area and adsorption capacity in bottle-point isotherm. 2. The adsorption capacity of coconut activated carbon for trichloroethylene (TCE) was reduced in the presence of humic substance. 3. A decrease in particle size of activated carbon resulted in higher adsorption capacity and lower intraparticle diffusion coefficient. It is reflected not only as a decrease in Freudlich adsorption capacity value (K) but also as an increase in Freudlich exponenent value (1/n).

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.46-50
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• 1997

The pH of coconut based activated carbon was changed by treating with NaOH and HNO3 and we have calculated the adsorption amounts of ammonia, hydrogen sulfide and methylmercaptan on the activated carbons using the break-through time which was obtained from break-through curve experiments. As a result of this study, the adsorption amounts of ammonia Has on the activated carbons were 2,6 mg/g, 17.2 mg/g and 31.6 mg/g with the pH 11, pH 7 and pH 3, respectively. These results indicated that the adsorption ability of ammonia on activated carbon was increased with decreasing the pH of activated carbon. Otherwise, in the cases of the adsorption experiment of hydrogen sulfide and methylmercaptan on the activated carbons with different pH. the activated carbon with pH 11 showed higher adsorption capacity than the activated carbons with pH 7 and pH 3. The adsorption amounts of hydrogen sulfide and methylmercaptan were 39.9 mg/g and 178 mg/g with pH 11, respectively. Finally, we analyzed the amount of ammonia delivered from 88 Lights cigarette made of triple filter which contained the activated carbon. The amount of ammonia delivered to smoke from the filter cigarette containing the activated carbon with pH 3 was 45.1${\mu}g$/cig. This value was lower 23.8 % than that from the activated carbon with the pH 11.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.16-23
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• 2023

Heavy metal (Zinc, Cadmium, Lead) adsorption onto surface modified activated carbon was performed in order to better understand the effect of sodium ion addition to activated carbon. Surface modification methods in this research included water washing, nitric acid washing, and sodium addition after nitric acid washing. These surface modifications generated oxygen functional groups with sodium ions on the surface of the activated carbon.. This caused the change of the specific surface area as well as in the ratio of the carboxyl groups. Heavy metal adsorption onto sodium-containing activated carbon was the most among the three modifications. After the adsorption of heavy metals, the carboxyl group ratio decreased and sodium ions on the surface of the activated carbon were almost non-existent after the adsorption of heavy metals onto sodium-containing activated carbon. The results from this research indicated that ion exchange with sodium ions in carboxyl groups effectively improved heavy metal adsorption rather than electrostatic adsorption and hydrogen ion exchange.

• Carbon letters
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• v.2 no.1
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• pp.9-14
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• 2001

Adsorption and desorption characteristics of methyl iodide at high temperature conditions up to $250^{\circ}C$ by TEDA-impregnated activated carbon, which is used for radioiodine retention in nuclear facility, was experimentally evaluated. In the range of temperature from $30^{\circ}C$ to $250^{\circ}C$, the adsorption capacity of base activated carbon decreased sharply with increasing temperature but that of TEDA-impregnated activated carbon showed higher value even at high temperature ranges. Especially, the desorption amount of methyl iodide on TEDA-impregnated carbon represented lower value than that on unimpregnated carbon. The breakthrough curves of methyl iodide in the fixed bed packed with base carbon and TEDA-impregnated activated carbon at high temperature were compared. TEDA-impregnated activated carbon would be applicable to adsorption process up to $150^{\circ}C$ for the removal of radioiodine in a nuclear facility.

• Carbon letters
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• v.5 no.4
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• pp.170-179
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• 2004

The equilibrium and dynamic adsorption of methylene blue from aqueous solutions by activated carbons have been studied. The equilibrium studies have been carried out on two samples of activated carbon fibres and two samples of granulated activated carbons. These activated carbons have different BET surface areas and are associated with varying amounts of carbon oxygen surface groups. The amounts of these surface groups was enhanced by oxidation with $HNO_3$ and $O_2$ gas at $350^{\circ}C$ and decreased by degassing at increasing temperatures of $400^{\circ}$, $650^{\circ}$ and $950^{\circ}C$. The adsorption increases on oxidation of the carbon surface and decreases on degassing. The increase in adsorption has been attributed to the formation of acidic carbon-oxygen surface groups and the decrease in adsorption on degassing to their elimination. The dynamic adsorption studies have been carried out on the two granulated activated carbons using two 50 mm diameter glass columns at a feed concentration of 300 mg/L and at different hydraulic loading rates (HLR) and bed heights. The minimum achievable concentrations are comparatively lower while the adsorption capacities are higher for GAC-S under the same operating conditions. The adsorption capacity of a carbon increases with increase in HLR but the rate of increase decreases at higher HLR values.