• Journal of the Korean Ceramic Society
• /
• v.44 no.11
• /
• pp.607-612
• /
• 2007

Zn-AC and Zn-H-AC series prepared from non- and surface-modified activated carbon were investigated in terms of their hydrogen production capacity. An increase in the concentration of the zinc salts used with these series was shown to lead to a decrease in the values of the surface textural properties. The existence of zinc complexes on the surface was confirmed from an analysis of XRD data. The SEM micrographs of the two different sample types showed that the transformation of the carbon surface with an acid pre-treatment significantly change the metal contents on the surfaces of the carbon matrix. The EDX spectra indicated that all of the samples were richer in the amount of oxygen and zinc compared to any other elements. The results obtained using the Boehm's titration method showed that the positive introduction of the acidic groups on the carbon surfaces with the acid treatment is correlated with an increase in the amounts of zinc complexes with variation of the acidic groups. In terms of the hydrogen production performance, the volume fractions of the Zn-H-AC series were found to produce higher amounts than the Zn-AC series as a function of the metal contents considering the effects of the acid treatment.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.307-312
• /
• 2001

Adsorption capacities of toxic heavy metal ions using as-received carbon(AC), single and double surface-modified activated carbon(OAC and DSMC) in wide pH ranges are extensively evaluated. Physical and chemical properties of surface-modified activated carbons are evaluated through BET analysis, surface acidity and oxides measurements. Based oil tile adsorption isotherms of Pb, Cd and Cr ions by AC, OAC and DSMC, the adsorption amount on DSMC was obviously higher than that on the other carbons. Breakthrough behaviors of ternary metal ions in a column packed with three kinds of carbon were also characterized with respect to the variations of the influent pH and concentration. The adsorption capacity of DSMC in a fixed bed stood a favorable comparison with that of as-received carbon.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.73-76
• /
• 2007

In this study, methane gas adsorption ability of activated carbon (AC) with surface functional group effect, adsorbed methane amount was evaluated after nitric acid and ureatreatment of AC surface. Specific surface area and pore distribution of AC were studied though nitrogen adsorption isotherm at 77 K. Micro pore volume was calculated through H-K method. Adsorbed methane amount was evaluated through volume method at room temperature by using auto adsorption apparatus. Adsorbed methane amount of AC was found to increase with to specific surface area increase.Correlation proposed between the methane adsorption amount and surface nature indicates that the surface nature plays an important role on the adsorption amount at a given temperature.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.739-744
• /
• 2009

The filter has long been used in purification processes for indoor air quality. To determine the deodorization effect of several filter materials in a full-scale air-handling system, the present study has been carried out using a wind tunnel equipped with a heat exchanger and various filter materials, such as commercial fabric, activated carbon(AC) and silver nano-particles attached to activated carbon(Ag-AC). The experiment was conducted using an odor substance with ammonia, acetaldehyde, acetic acid. The results obtained indicate that odor substance is substantially decreased on the moisture condensation on the surface of the heat exchanger. The fabric filter has no effect for removal of odor substances. The deodorization efficiency is found to be approximately 7% in the AC filter, while the deodorization efficiency is increased up to 10% using the Ag-AC filter.

• Journal of the Korean Ceramic Society
• /
• v.46 no.1
• /
• pp.1-9
• /
• 2009

Activated carbon modified with nickel (Ni-AC) was employed the for preparation of Ni-activated carbon/$TiO_2$ (Ni-AC/$TiO_2$) composites. The $N_2$ adsorption data showed that the composites had a decreased surface area compared with pristine AC. This indicated blocking of the micropores on the surface of the AC, which was further supported by observation via SEM. XRD results showed that the Ni-AC/$TiO_2$ composite contained a mixed anatase and rutile phase while the untreated AC/$TiO_2$ contained only a typical single and clear anatase phase. EDX results showed the presence of C, O, and Ti with Ni peaks on the composites of Ni-AC/$TiO_2$. Subsequently, the photocatalytic effects on methylene blue (MB) were investigated. The improved decomposition of MB showed the combined effects of adsorptions and photo degradation. In particular, composites treated with Ni enhanced the photo degradation behaviors of MB.

• Korean Chemical Engineering Research
• /
• v.61 no.3
• /
• pp.472-478
• /
• 2023

In this study, the acetaldehyde removal characteristics of activated carbon (AC) for air purifier filters were investigated using metal catalysts-impregnation and functional group-modification method. The AC with a high specific surface area(1700 m²/g) and micropores was prepared by KOH activation of coconut charcoal and the efficiency of catalyst and functional group immobilization was examined by varying the drying conditions within the pores after immersion. The physical properties of the prepared activated carbon were analyzed by BET, ICP, EA, and FT-IR, and the acetaldehyde adsorption performances were investigated using gas chromatography (GC) at various impregnation and modified conditions. As the concentration of impregnation solution increased, the amount of impregnated metal catalysts increased, while the specific surface area showed a decreasing trend. The adsorption tests of the metal catalyst-impregnated and functional group-modified activated carbons revealed that excellent adsorption performance in compositions MgO10@AC, CaO10@AC, EU10@AC, and H-U3N1@AC, respectively. The MgO10@AC, which showed the highest adsorption performance, had a breakthrough time of 533.8 minutes and adsorption capacity of 57.4 mg/g for acetaldehyde adsorption. It was found that the nano-sized MgO catalyst on the activated carbon improved the adsorption performance by interacting with carbonyl groups of acetaldehyde.

• Journal of environmental and Sanitary engineering
• /
• v.16 no.1
• /
• pp.72-90
• /
• 2001

This study was conducted to evaluate desorption efficiencies accuracy and precision by $CS_2$ and thermal desorption method for polar and non-polar organic solvents collected on activated carbon(AC), activated carbon fiber(ACF), carbosieve SIII, materials tested were Methyl alcohol, n-Hexane, Benzene, Trichloroethylene, Methyl isobutyl ketone and methyl cellosolve acetate and six different concentration levels of samples were made. The results were as follows ; 1. Accuracy on kind adsorbent and desorption method was low. In case of $CS_2$ desorption solvent, Overall B and Overall CV on AC and ACF were 43% and 6.63%, respectively. In case of thermal desorption method, accuracy of thermal desorption method appeared higher than solvent desorption method by AC 18.0%, 3.54%, ACF 2.6%, 2.57%, Carbosieve SIII 13.7% and 1.97%, respectively. 2. In the concentration level III, accuracy of thermal desorption method on adsorbent was in order as follow ; ACF > Carbosieve SIII > AC in the methyl alcohol and Carbosieve SIII > ACF > AC in the rest of them all subject material and Concentration levels showed good precision at EPA recommend standard (${\leq}{\;}30%$) 3. DEs by type of organic solvent adsorbent and desorption method are as follows ; In the case that desorption solvent is $CS_2$, DE of Methyl alcohol is AC 47.5%, DE of all materials is ACF about 50%. In the case of thermal desorption method, DE of Methyl alcohol is AC 82.0%, ACF 97.4%, Carbosieve SIII 86.3%. DE of the later case is prominently improved more than one of former. In particular, Except that DE of EGMEA is ACF 88.5%, DE of the rest of it is more than 95% which is recommend standard MDHS 72. With the result of this study, in order to measure various organic solvent occurring from the working environment, in the case of thermal desorption method, we can get the accurate exposure assessment, reduce the cost, and use ACF as thermal desorption sorbent which available with easy.

• Journal of the Korean Chemical Society
• /
• v.62 no.2
• /
• pp.79-86
• /
• 2018

This study reported the adsorption of Cu(II) ions onto activated carbon prepared from Myristica Fragrans shell (MFS AC) over independent variables of contact time, activating chemical (NaOH) concentration, initial adsorbate concentration, initial pH of adsorbate solution and adsorption temperature. The MFS AC structure, morphology and total surface area were characterized by FTIR, SEM and BET techniques, respectively. The Cu(II) ions adsorption on the MFS AC (activated using 0.5 M NaOH) fitted best to Freundlich adsorption isotherm (FAI), and the FAI constant obtained was 0.845 L/g at $30^{\circ}C$ and pH 4.5. It followed the pseudo first order of adsorption kinetic (PFOAK) model, and the PFOAK based adsorption capacity was 107.65 mg/g. Thermodynamic study confirmed the Cu(II) ions adsorption should be exothermic and non-spontaneous process, physical adsorption should be taken place. The total surface area and pore volume based on BET analysis was $99.85m^2/g$ and 0.086 cc/g, respectively.

• Analytical Science and Technology
• /
• v.12 no.2
• /
• pp.105-110
• /
• 1999

The studies on the adsorption properties and the antibacterial effects of the Cd and Cu-treated activated carbon were carried out. From the adsorption studies on the series of these metal-treated activated carbons, typical Type-I isotherm was observed. The surface areas of the treated carbon obtained from BET equation were in the range of $1101-1418m^2/g$ for Cd-AC and of $1084-1361m^2/g$ for Cu-AC. Using ${\alpha}_s$-plot, the micropore volumes and pore size distribution were obtained. From the SEM study, it is also observed that many of micropores in activated carbon are blocked by window blocking effect of metals after the impregnation. Finally, antibacterial effects of M-activated carbon against Escherichia coli was discussed. From the study, the area of antibacterial activity becomes larger with the increase of the amount of metal treated.

• Carbon letters
• /
• v.10 no.1
• /
• pp.33-37
• /
• 2009

Activated carbon (AC) is one of the most effective adsorbents for organic compounds because of their extended surface area, high adsorption capacity, microporous structure and special surface reactivity. The composites of pH-sensitive hydrogel and activated carbon were prepared in order to improve the loading capacity of drug. The pH-sensitive hydrogel matrix swelled well in the basic condition to release the drug loaded in AC. The release of drug was controlled depending on both the pH due to the ionization of the carboxylic acid group and the AC due to the surface properties.