• Carbon letters
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• v.3 no.4
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• pp.198-204
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• 2002

In this paper, impregnated activated carbon fiber (IACF) was manufactured to pitch-based activated carbon fibers (ACF) with potassium hydroxide (KOH) by using wet impregnation method to raise nitrogen oxides ($NO_x$) adsorptivity. The properties of IACF were observed using EPMA, TGA and DSC and $NO_x$ adsorptivity was observed at high and low temperature. Before and after adsorption was analyzed using ToF-SIMS for examine surface characterization of adsorbed $NO_x$. The results showed that the better adsorptivity appeared for increasing KOH ratio. So, $NO_x$ adsorptivity showed result that is proportional between KOH and the adsorbed amount. On the other hand, adsorbent that manufactured without washing was better $NO_x$ adsorptivity than adsorbent that manufactured with washing. The behavior of adsorption show that crossing time of NO and $NO_2$ delayed for a rising adsorptivity. And NO ratio increased but $NO_2$ ratio decreased according as KOH ratio increases. $NO_x$ was confirmed through surface analysis that remain in $NO_2^-$ and $NO_3^-$ form on IACF surface.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1463-1471
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• 2015

The surface modified activated carbons (SMACs) were prepared with various $P_2O_5$ concentrations using two activated carbons (ACs: waste citrus peel-based activated carbon and coconut-based activated carbon). The characteristics and adsorptivity of bisphenol A (one of phenolic endocrine disrupting chemicals) were compared between ACs and SMACs. The contents of C, H and N of SMACs were similar to those of ACs, but the content of $P_2O_5$ for the former increased greatly than for the latter, due to the impregnation of $P_2O_5$ into the pores. The specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former decreased due to the impregnation of $P_2O_5$ into the pores, compared to those for the latter. The adsorptivity of bisphenol A for the former were higher than that for the latter, although specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former were lower than those for the latter.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.156-171
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• 1992

Chitin was isolated from crab shell. Chitosan, which was prepared by the deacetylation of chitin, was acylated to obtain N-acetyl(regenerated chitin), N-propionyl, N-butyryl, N-hexanoyl, N-decanoyl and N-maleated chitosans and their metal ion adsorption characteristics of N-acylchitosans were investigated. In order to enhance the adsorptivity, their porous beads were prepared and their adsorptivity with respect to the porosity and the adsorptivities for metal ions($Cu^{2+}$, $Ni^{2+}$, $CO^{2+}$, $Mn^{2+}$, $Ag^{+}$)were investigated. Their metal ion adsorptivities were remarkably imporved compared to those of chitin. As the larger acyl groups were introduced, adsorptivity increased, but that of N-decanoyl chitosan showed some decrease because of steric hindrance of the bulky N-decanoyl group. N-Maleated chitosan containing carboxyl group showed highly improved adsorptivity, and N-acylchitosans showed the good selective adsorption in the mixed metal ions($Cu^{2+}$, $Ni^{2+}$, $CO^{2+}$, $Mn^{2+}$ and $Ag^{+}$). They also showed excellent adsorption characteristics as chelating polymers.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.649-654
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• 2017

An activated carbon was prepared from waste citrus peel produced in large amounts in Jeju Island, Korea, using KOH activation and its characteristics was examined. Under the condition of the KOH ratio between 100 and 300%, activation temperature from 400 to $900^{\circ}C$ and activation time from 0.5 to 1.5 h, the iodine adsorptivity of the activated carbon prepared increased but the yield decreased with respect to the increase of each conditions. The iodine adsorptivity and yield of the activated carbon prepared at the activation time of more than 1.5 h were similar to those of using 1.5 h. In addition, as the KOH ratio increased, the specific surface area and pore volume of the activated carbon increased, but the pore diameter decreased. The activated carbon has an average pore diameter of $20{\sim}25{\AA}$. Also, the activated carbon prepared at 300% KOH and $900^{\circ}C$ for 1.5 h has the highest specific surface area of $1,527m^2/g$ and iodine adsorptivity of 1,246 mg/g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.400-405
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• 2010

This study investigated lead adsorption by carboxylated alginic acid and its application in cleansing cosmetics. Carboxylated alginic acid showed the highest lead adsorptivity after oxidation in a 4-6 mM hydrogen peroxide solution at $20-30^{\circ}C$ for 30-40 min. Carboxylated alginic acid adsorbed $648.1{\pm}2.8-653.0{\pm}2.9$ mg/g of lead dry mass at pH 4-6. Carboxylated alginic acid modified by hydrogen peroxide and potassium permanganate adsorbed $651.3{\pm}3.8$ and $639.9{\pm}4.0$ mg/g of lead dry mass, respectively. Carboxylated alginic acid showed higher lead adsorptivity after modification by hydrogen peroxide than by potassium permanganate, with an increase of ~30% compared with raw alginic acid. To access the potential application of carboxylated alginic acid in cleansing cosmetics, we investigated the lead adsorptivity, conditions of the cosmetics procedure, and cytotoxicity of various concentrations of cleansing cosmetics added to 5% carboxylated alginic acid. The ideal cosmetic concentrations combined with 5% carboxylated alginic acid were 70% for peeling gel, 20% for massage cream, 20% for foam cleansing and 40% for cleansing cream. There was no cytotoxicity in cleansing cosmetics combined with 5% carboxylated alginic acid.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.53-59
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• 1973

The adsorptivity of Methylene Blue on Korean Yeongil bentonite which was premixed with a salt of KF or $NH_{4}Cl$ etc., treated at $200-500^{\circ}C$, washed and dried, was studied. In case of treatment with$NH_{4}Cl$, slight improvement of the adsorptivity of methylene blue on the products was observed. With KF, treated at$200-300^{\circ}C$, the best results was obtained. The adsorption capacity of the products was improved about 1.7 times than that of original bentonite. With $FeSO_4$ or $Na_{2}CO_3$ etc. improvement of the adsorption capacity on the products was not observed.

• Journal of Environmental Science International
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• v.12 no.7
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• pp.817-824
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• 2003

Various kinds of zeolites, such as analcime (ANA), cancrinite (CAN), Na-Pl and sodalite octahydrate (SOD) could be synthesized from Hwangto by hydrothermal reaction in a high-pressure vessel. The adsorption characteristics of Cu(II) and Cd(II) by Hwangto and its synthetic zeolites were investigated using the chemical and electrochemical surface parameters of these adsorbents. The heavy metal adsorptivity among the adsorbents decreased in the following sequences: Na-Pl > SOD > ANA > CAN > Hwangto. This sequence was the same with the values of surface site density (Ns) of these adsorbents and was correlated inversely with the values of pHpzc (pH of the point of zero charge) and the va]ues of K$\_$a2/(int) (intrinsic surface deprotonation constant) of the adsorbents for synthetic zeolites, i.e., the adsorbents with higher values of Ns and with lower values of pHpzc and K$\_$a2/(int) for synthetic zeolites showed higher heavy metal adsorptivity. With increasing pH, the heavy metal adsorptivity increased greatly between pHpzc and pH 6 or 7 because of the steep increase of negatively charged sites for synthetic zeolites, but for Hwangto, it increased broadly because of slow increase of negatively charged sites based on its lower surface sites.

• Analytical Science and Technology
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• v.10 no.4
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• pp.291-299
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• 1997

2,2'-iminodibenzoic acid-cellulose was prepared by reacting 2,2'-iminodibenzoic acid salt with cellulose-Cl obtained by chlorination of cellulose-OH which is the major component of sawdust. The adsorptivity of Pb(II) and Cu(II) was studied using the synthetic chelating adsorbent. The adsorption amounts of those ions increased with increasing pH and the optimum adsorption time of metal ion was about 1hr. The adsorptivity of Pb(II) was larger than that of Cu(II).

• Nuclear Engineering and Technology
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• v.12 no.2
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• pp.121-126
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• 1980

Selection methods of well labelled insulin fractions based on two different criteria were compared to establish an efficient low level RIA of insulin and to elucidate the correlation between the immunoreactivity and the charcoal-adsorptivity of the radioiodine labelled insulin. The results indicated that the selection of well labelled insulin fractions by means of a charcoal-adsorption test is inappropriate. Generally, the distribution of radioactivity antibody-bindability, and charcoal-adsorptivity of the labelled insulin was not consistent with each other. Thus. the selection should be carried out for every labelling batch to get the utmost assay reliability by antibody-bindability but not by charcoal-adsorptivity. By using the well selected labelled insulin fractions based on antibody-binding, a correct assay for a reference serum was possible, and by extending the incubation time upto 96 hrs, a sharp dose response curve could be obtained even in the range of below 5 $\mu$U/ml standard insulin doses.

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.20-29
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• 2005

Cotton fabric was treated with a reactive anionic agent in order to have anionic sites(-S03-) on it, which made it possible for the fabric to adsorb various cationic materials. In this study, the adsorptivity of various heavy metal ions such as Pb(II), Cd(II), Cr(III), Co(II), Cu(II), Ni (II) and Cr(VI) on the cotton fabrics treated with anionic agent was examined at the various conditions; concentrations of heavy metal ions, pHs of solution, reaction time and temperature. As a result, the adsorptivity of the heavy metal ions on the cotton fabrics treated with the anionic agent was highly increased comparing to that of untreated cotton fabrics. The order of the adsorptivity was as follows: $Pb(II)>Cd(II)>Cu(II)\geqNi(II)\geqCo(II)>Cr(III)\ggCr(VI)$. The adsorption amounts of most heavy metal ions were increased in weak alkaline conditions and were reached to an adsorption equilibrium within 10 ~ 30 minutes. The maximum adsorption ratios of Pb(II) and Cd(II) were respectively 99% and 80% of the initial concentration of heavy metal ions. Therefore the anionized cotton fabrics seem to be utilized as an adsorption fabrics for the removal of heavy metal ions in the waste water.