• Analytical Science and Technology
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• v.13 no.5
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• pp.573-583
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• 2000

Activated carbon fibers (ACFs) were prepared from various precursors of plantic, synthetic, and mixed fabrics of viscous rayon and cotton. Their adsorption performances of phenol and methylene blue in aqueous phase were evaluated through their adsorption isotherms, adsorption rates and breakthrough curves. The two adsorbates showed type I adsorption isotherm on ACFs. Adsorption rates to ACFs were 100 fold faster than to GAC. The effective diffusion coefficients of the adsorbates in ACFs were twenty fold greater than in GAC. The ACFs removed completely ten organic pollutants from a prepared water specimens through the 2nd column of a natural filtration method where 50 L of the water samples were treated.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.15-21
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• 2006

The objective of this research is to develop the technique for carbonization of wood pellet and analyze a possibility for the utilization of carbonized wood pellet. The properties of wood pellet charcoals, such as density, yield, elemental composition, higher heating value, and methyleneblue adsorption, were analyzed. Wood pellet was made of sawdust of Hyunsasi-poplar, Japanese larch, Korean pine, Korean red pine, and Jolcharn-oak (serrate oak), respectively. The high density charcoal ($0.5{\sim}0.7g/cm^3$) was yielded from densified wood pellet. The carbon contents and calorific values of wood pellet charcoals were increased with the increase of carbonization temperature. The methyleneblue adsorptivity of wood pellet charcoal was similar to that of wood charcoal.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.381-388
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• 1974

When mixture of p-phenylenediamine (PPD) and m-aminophenol (MAP) were reacted with formaldehyde (F) varying their amounts under $N_2$ stream at the temperature of -5∼0$^{\circ}$, addition condensation reaction occurred and brown colored resins(in some cases orange colored) were formed immediately. All resins thus formed were insoluble in most ordinary organic solvents and did not melt up to 300$^{\circ}$. When the resins were treated with dilute(7 %) aqueous sodium hydroxide solution, the adsorptivity of methylene blue on them showed marked improvement reaching as much as 80 mg of methylene blue on 1 g of the resin. On the other hand, in the case of bromophenol blue, its amount of adsorption appeared 250 mg per 1 g of the resin. The TGA under $N_2$ atmosphere indicated that the resin formed in molar ratio of 1 : 3 : 8 (PPD : MAP : F) showed the best heat-resistant property among others. About 40 % weight loss was observed for this resin at 900$^{\circ}$ with heating rate of 2$^{\circ}$ per minute.

• Journal of the Korean Wood Science and Technology
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• v.38 no.1
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• pp.27-35
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• 2010

To evaluate the basic characteristics and adsorption properties of commercial wood charcoal, we investigated the proximate analysis, porosimetry analysis, methylene blue adsorption, removal ratios of formaldehyde, and removal ratio of ethylene gas. Fixed carbon contents of traditional black and white charcoal, and mechanical charcoal were 51.8~76.6%, 72.9~84.6%, and 48.5~80.3%, respectively. Refining degrees of the most traditional black charcoal were 9, and those of white charcoal and mechanical charcoals were zero. Specific surface area of traditional black charcoal was 0.1~13.7 $m^2/g$, which was quite lower than that of white charcoal (53.2~372.6 $m^2/g$) and mechanical charcoals (224.3~464.6 $m^2/g$). Also, amounts of methylene blue adsorption were quite lower in black charcoal (0.53~1.97 mg/g) compared with white charcoal (2.68~7.68 mg/g) and mechanical charcoal (11.63~26.10 mg/g). Removal ratios of formaldehyde of the black charcoal were 11.4~26.7%, which is quite similar to white charcoal (17.9~34.9%) and mechanical charcoal (5.5~25.8%). Removal ratios of ethylene gas for traditional black charcoal, traditional white charcoal, and mechanical charcoal were 2.2~43.5%, 21.7~39.1%, 21.7~39.1%, respectively. There was no significant difference in the removal ratios of formaldehyde and ethylene gas among traditional black charcoal, traditional white charcoal, and mechanical charcoal.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.146-152
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• 2005

The activated carbon was produced from Sancheong bamboo by carbon dioxide gas activation methods. The carbonization of raw material was conducted at $900^{\circ}C$, and $CO_2$ activation reactions were conducted under various conditions: activation temperatures of $750-900^{\circ}C$, flow rates of carbon dioxide $5-30cm^3/g-char{\cdot}min$, and activation time of 2-5 h. The yield, adsorption capacity of iodine and methylene blue, specific surface area and pore size distribution of the prepared activated carbons were measured. The adsorption capacity of iodine (680.8-1450.1 mg/g) and methylene blue (23.5-220 mg/g) increased with increasing activation temperature and activation time. The adsorption capacity of iodine and methylene blue increased with the $CO_2$ gas quantity in the range of $5-18.9cm^3/g-char{\cdot}min$. But those decreased over those range due to the pore shrinkage. The specific volume of the mesopore and macropore of bamboo activated carbon were $0.65-0.91cm^3/g$. Because of this large specific volume, it can be used to the biological activated carbon process. Bamboo activated carbon phisically adsorbed the $CO_2$ of maximum 106 mg/g-A.C in the condition of 90% $CO_2$ and adsorption temperature of $20^{\circ}C$. The $CO_2$ adsorption ability of bamboo activated carbon was not changed in the 5 cyclic test of desorption and adsorption.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.259-272
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• 2002

This study was tried to interpret the important major factors controlling some physicochemical properties by comparing mineralogical and physicochemical characteristics such as pH, cation exchange capacity, Methylene Blue adsorption amount, swelling, viscosity, strength (compressional and tensile), and surface area etc. Investigated bentonite samples are five Korean samples from Dusan, Naa, Oksan, Dongyang, and Yeonil deposits and two Japanese bentonites from Tsukinuno and Tomioka deposits which were formed under a similar geological environment of the Tertiary basin. Tsukinuno bentonite is only natural Na-type bentonite and the others are all Ca-type bentonites. Most of the properties are not explained by the montmorillonite content only though the most important factor controlling the physicochemical properties is the montmorillonite content. The layer charge of montmorillonite will strongly control cation exchange capacity and Methylene Blue adsorption. Zeolite bearing bentonites show the strong alkaline character and causes the increase of cation exchange capacity, however decrease swelling, viscosity and strengths. Pyrite bearing bentonites decrease green compressional strength and wet tensile strength. The exchangeable interlayer cations control some physicochemical properties. Na-type bentonite than Ca-type shows more strong alkaline character and much more advanced swelling and viscosity. Also the size and thickness of montmorillonite flakes seem to control some physicochemical properties. Bentonite mainly composed of montmorillonite of very thin and large flakes is characterized by the very high surface area, cation exchange capacity, viscosity, swelling, Methylene Blue adsorption, green compressional strength and wet tensile strength. Domestic Dusan bentonite shows the most excellent physicochemical properties, which is due to the high content(84%) and very well crystallinity of montmorillonite.

• Clean Technology
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• v.27 no.4
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• pp.359-366
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• 2021

Halloysite nanotubes (HNTs), the multiwalled clay mineral with the composition of Al₂Si₂O₅(OH)₄·nH₂O, have been highlighted as a low-cost adsorbent for the removal of dyes from wastewater. Although a powder of halloysite presents a high specific surface area, forming media are significantly considered due to sludge-clogging induced by the water-bound agglomeration. However, higher firing temperature to achieve the structural durability of the media and lower utilization rate due to longer penetration depth into the media act as hurdles to increase the dye-adsorption capacity. In this work, the retention of the adsorption capacity of halloysite was evaluated with methylene blue solution after the heat treatment at 750 ℃. In order to improve the utilization rate, tubular media were fabricated by extrusion. The images taken by transmission electron microscopy show that HNTs present excellent structural stability under heat treatment. The HNTs also provide superb capacity retention for MB adsorption (93%, 18.5 mg g^-1), while the diatomite and Magnesol^® XL show 22% (7.65 mg g^-1) and 6% (11.7 mg g^-1), respectively. Additionally, compositing with lignin enhances adsorption capacity, and the heat treatment under the hydrogen atmosphere accelerates the adsorption in the early stage. Compared to the rod-type, the tubular halloysite media rapidly increases methylene blue adsorption capacity.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.40-51
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• 2006

The objective of this research is to analyze a possibility for the utilization of carbonized bark and develop the technique for carbonization of bark for using as the adsorbent, the soil improvement agent, the carrier for microbial activity, health products, and so on. The properties of bark charcoals such as methylenehlue adsorption (MBA), equilibrium moisture content (EMC), far infra rad emissivity, pH, water retention and caloric value were analyzed. The MBA values of bark charcoals carbonized for 8 hr of carbonization time at $800^{\circ}C$ of carbonization temperature for Larix leptolepis, Pinus koraiensis, Pinus rigida were greater than 110 mg/g. The bark charcoals pH values of all three species that were carbonized for 4 hr of carbonization time at $400^{\circ}C$ of carbonization temperature was 6.6 and carbonized for 4 hr at 600 and $800^{\circ}C$ was about 9. Therefore the bark charcoals of those species could be used as charcoals if the carbonization temperature and time were controlled.

• Analytical Science and Technology
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• v.20 no.3
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• pp.193-197
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• 2007

In this study, the effect of metal treatment on granular activated carbon (GAC) was investigated in the context of phenol adsorption. Cobalt(II) nitrate, and zinc(II) nitrate solution were used for metal treated. The specific surface area and the pore structure were evaluated from nitrogen adsorption data at 77 K. The phenol adsorption rates onto GAC were measured by UV-Vis spectrophotometer. Iodine adsorption capacity of Co-GAC is much better then that of the GAC. The Co-GAC with mesopore is more efficient than other adsorbents for the adsorption of polymer such as methyleneblue. The adsorption capacity of reference-GAC and metal-GAC were increased in order of Co-GAC>Zn-GAC>Reference-GAC, in spite of a decrease in specific surface area which was resulted from pore blocking by metal.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.33-40
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• 2002

This research was to investigate the adsorption characteristics of charcoals of major Korean wood species (thinned trees) and wood-based materials. As carbonization time and temperature increased, methylene-blue adsorption (MBA) of charcoals of thinned trees and wood-based materials increased. Pinus koraiensis charcoal showed the highest MBA. MBA of softwoods was higher than that of hardwoods. There was a negative correlation between air-dried specific gravity before carbonization and MBA of carbonized thinned trees. The MBA of wood-based materials showed similar value, but wood-based materials in MBA was lower than thinned woods. Surface area and total pore volume of thinned trees and wood-based materials increased as carbonization temperature increased. The species showing highest MBA appeared to have the highest surface area at the carbonization temperature of 600℃ as well. There was a positive correlation between surface area, total pore volume and MBA of charcoals. The charcoal of wood-based materials generally exhibited micro pores.