• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.371-379
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• 2005

Adsorption equilibria of the gases $H_2$, $CH_4$, and $C_2H_4$ and their binary mixtures on activated carbon (Calgon co.) have been measured by static volumetric method in the pressure range of 0 to 18 atm at temperatures of 293.15, 303.15, and 313.15 K. From the parameters obtained from single component adsorption isotherm, multi-component adsorption equilibria could be predicted and compared with experimental data. The binary experimental data were applied to four models : extended Langmuir, extended Langmuir-Freundlich, Ideal Adsorbed Solution theory (IAST), and Vacancy Solution Model (VSM). The models were found to describe the experimental data with a reasonable accuracy. Extended L-F model predicts equilibria of mixture better than any other model.

• Restorative Dentistry and Endodontics
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• v.28 no.6
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• pp.435-448
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• 2003

This study was performed to observe the antibacterial effect of polyphosphate (polyP) with various chain lengths (P3~P75) on virulent. invasive strains of P. gingivalis A7A1-28 and W50, and multidrug resistant E. faecalis ATCC29212. P. gingivalis strains were grown in brain-heart infusion broth (BHI) containing hemin and vitamin K with or without polyP. PolyP was added at the very beginning of the culture or during the exponential growth phase of the culture. Inhibition of the growth of P. gingivalis was determined by measuring the absorbancy at 540nm of the grown cells. Viable cell counts of the culture and release of intracellular nucleotide from P. gingivalis were measured. E. faecalis was grown in plain BHI with antibiotics alone or in combination with polyP(calgon: 0.1~1.0%) and the bacterial absorbancy was measured. The overall results suggest that polyP has a strong antibacterial effect on the growth of the virulent strains of P. gingivalis and the antibacterial activity of polyP seems largely bactericidal. accompanying bacteriolysis in which chelation phenomenon is not involved. Although polyP does not exert antibacterial activity against E. faecalis, it appears to increase antibacterial effect of erythromycin and tetracycline on the bacterium. Therefore, polyP alone or in combination with antibiotics may be developed as a candidate for the agent controlling oral infections including endodontic infection.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.156-164
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• 1998

This study was performed to select media for the development of biological activated carbon process. Using activated carbon made by Norit, Calgon, Samchully Co., removal efficiency of humic acid by the isothermal adsorption test and biodegradation of organic matters by microbes attached to BAC and observation and counting of microbes attached to BAC were examined. The removal efficiency of humic acid with dose of activated carbon was influenced by initial concentration. Compared with other activated carbon, Norit was found to be most effective in view of adsorption capacity, biodegradation of organic matter, and attachment characteristics of microorganism. In conclusion, Norit which has high adsorption capacity and good biodegradation of organic matter was recommended for selecting media in BAC process.

• Carbon letters
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• v.1 no.2
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• pp.82-86
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• 2000

The present research was undertaken to evaluate the possibility of water purification filter with activated carbon fibers (ACFs) using a very low cost precursor consisting of phenolic resin coated on glass fibers. The simplified procedure involving coating, curing and activation and a very low cost glass fiber as a raw material were adopted in order to reduce manufacturing cost. The breakthrough curves of the manufactured ACFs and the commercial activated carbon (AC, Calgon F-200) were investigated in the initial concentration range from 19 to 49 ppm for benzene, toluene and ethylbenzene. From breakthrough profiles, the manufactured ACFs had significantly faster adsorption kinetics than the AC. Especially the benzene breakthrough curves, the manufactured ACF (13 g of ACF with 32% of carbon on the glass) was over the limited level (5 ppb) after flowing of 32 l at initial concentration of 15 ppm, while the commercial AC was shown about 3 ppm in initial adsorption.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.69-79
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• 2003

The purpose of this present study was to develop a new way of self-curing acrylic resin, using commercially available polyphosphate, Calgon, which is known to be antimicrobial and safe. For the study, polyphosphate(polyP) was blended with acrylic powder and devided into four groups as follows: no polyP(control), 1% polyP, 2% polyP, and 3% polyP. For the experiment, Streptococcus mutans GS5, Streptococcus sobrinus 6715, Streptococcus gordonii G9B and Challis, Porphyromonas gingivalis 2561, and Candida albicans ATCC 90027 were used. Resin specimens in each group were tested in vitro for the purpose of investigating the effect of polyP on the microbial attachment, growth and hydrophobicity of the resin surface. The results were as follows. 1. PolyP added to the acrylic resin decreased attachment of S. mutans GS5, S. sobrinus 6715, S. gordonii G9B. The greater binding inhibition was found in acrylic resin polymerized with polyP at higher concentrations. 2. The addition of polyP to acrylic resin failed to significantly affect the growth of the tested microorganisms. 3. The addition of polyP to acrylic resin seemed to reduce hydrophobicity of the acrylic resin. PolyP in acrylic resin does not seem to exert a direct antibacterial activity, but rather inhibit attachment of oral bacteria, especially mutans streptococci to saliva-coated acrylic resin. The acrylic resin reduces attachment of streptococci may be due to the decreased hydrophobicity caused by polyP added to the resin. PolyP may be included to acrylic resin to inhibit dental caries which often occurs when removable acrylic resin appliance is placed.

• Journal of Environmental Science International
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• v.16 no.11
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• pp.1279-1285
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• 2007

The activated carbon was prepared from waste citrus peels using NaOH. With the increase of NaOH ratio, iodine adsorptivity and specific surface area of the activated carbon prepared were increased, but activation yield was decreased. The optimal condition of activation was at 300% NaOH and $700^{\circ}C$ for 1.5 hr. For the activated carbon produced under optimal condition, iodine adsorptivity was 1,006 mg/g, specific surface area was $1,356 m^2/g$, and average pore diameter was $20{\sim}25{\AA}$. From the adsorption experiment for benzene vapor in fixed bed reactor, it was found that the adsorption capacity of activated carbon prepared from waste citrus peel was higher than that of activated carbon purchased from Calgon company. This result implied that the activated carbon prepared from waste citrus peel could be used for gas phase adsorption.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.438-443
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• 2007

This study was done to investigate perchlorate contamination in Nakdong river. The perchlorate was detected in Nakdong river and ranged from ND to $82.1{\mu}g/L$. The highest concentration was observed in Wheguan. The perchlorate concentration was decreased with the down stream of Nakdong river. Three different virgin activated carbons made of each coal(Calgon), coconut(Samchully) and wood(Picabiol) based activated carbon(AC) were tested for an adsorption performance of perchlorate in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of coal, coconut and wood based AC as 2,300 bed volumn(BV), 719 BV and 288 BV respectively. Adsorption capacity(X/M) of real, coconut and wood based AC was observed. The experimental results of adsorption capacity showed that coal based AC was highest$(768.2{\mu}g/g)$, coconut based AC was intermediate$(299{\mu}g/g)$ and wood based AC was lowest$(99.2{\mu}g/g)$. Moreover, carbon usage rates(CURs) for coal, coconut and wood based AC had been shown as 0.71 g/day, 2.16 g/day and 3.45 g/day respectively. The constant characteristic of the system, k of coal, coconut and wood based ACs were found to be 307.2, 102.5 and 94.2, respectively.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.141-152
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• 2001

Eliminating the infecting bacteria of the root canal system and preventing reinfection must be the main objectives of all endodontic works. None of commercially available root canal sealers have the properties of desirable tissue compatibility and strong antibacterial activity. The purpose of this study is to develope an ideal root canal sealer using commercially available polyphosphate (polyP), Calgon, which is known to be antibacterial and safe. For the study. resin type AH26, zinc oxide eugenol type Tubli Seal. Ca(OH)$_2$ type Apexit as base sealers for polyP (0~3%) and para formaldehyde containing N2 as a control base were selected. Specimens (3$\times$4mm) of the sealers were prepared in a 37$^{\circ}C$ incubator for 3 and 10 days and their antibacterial activity against streptococci and black pigmented anaerobic rods was observed using an agar diffusion method. The result were as follows: 1. Among 3 day old root canal sealers. N2 as a positive control showed the strongest antibacterial effect. followed by AH26. Tubli Seal and. Apexit which barely showed antibacterial activity against the test bacteria. In contrast. 10 day old AH26 showed a greater antibacterial activity than 10 day old N2. 2. All sealer specimens showed a greater antibacterial activity against black pigmented anaerobic rods than streptococci. Three day old ones appeared to be more antibacterial than 10 day old ones except for Apexit. 3. As compared to N2, 3 day old AH26 demonstrated a similar antibacterial activity against black pig mented anaerobic rods but to a lesser extent to streptococci. Ten day old AH26 showed a greater antibacterial activity against black pigmented anaerobic rods than 10 day old N2. 4. As compared to AH26. Tubli Seal generally revealed a lower antibacterial activity but it showed a greater antibacterial activity aginst S. gordonii Challis. 5. Enhancement of antibacterial activity by polyP was more clearly observed when it was added to Ca(OH)$^{\circ}C$ based root canal sealers. Tubli Seal and N2. 6. The addition of polyP enhanced the antibacterial activity of 3 day old AH26 against S. gordonii G9B (16%) and Challis (29%), and P. gingivalis 2561 (24%) only. Moreover, polyP failed to increase antibacterial activity of 10 day old AH26 against the test strains but P. gingivalis A7A1 28(13%). 7. The addition of polyP increased the antibacterial effect of 3 day old Tubli Seal on several test bacteria including s. mutans GS 5 (50%). s. gordonii G9B (47%) and Challis (122%). and all the test strains of P. gingivalis (13~35%) except for 9 14K 1. The addition of polyP to 10 day old Tubli Seal increased antibacterial activity of the root canal sealer against most test strains. 8. 3 day old Apexit failed to show antibacterial activity. if any very little against S. mutans GS 5 and Pr. intermedia ATCC 49046. However. polyP increased its antibacterial activity by 50 and 69%, respectively. Increase of antibacterial activity of 10 day old Apexit by polyP was more clearly observed than that of 3 day old one.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1280-1286
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• 2006

Three different virgin activated carbons made of each coal(Calgon), coconut(Samchully) and wood(Picabiol) based activated carbon(AC) were tested for an adsorption performance of 1,4-dioxane in a continuous adsorption column. Breakthrough behavior was Investigated that the breakthrough points of coal, coconut and wood based AC were observed as 3600 bed volumn(BV), 1440 BV and 144 BV respectively. Adsorption capacity(X/M) of coal, coconut and wood based AC was observed. The reported results of adsorption capacity showed that coal based AC was highest(578.9 ${\mu}g/g$), coconut based AC was intermediate(142.3 ${\mu}g/g$) and wood based AC was lowest(7.4 ${\mu}g/g$) due to increasing specific surface area. Moreover, carbon usage rates(CURs) for coal, coconut and wood based AC had been shown as 0.48 g/day, 1.41 g/day and 6.9 g/day respectively. The constant characteristic of the system, k of coal based AC was found to be 91.5 and k of coconut based AC was found to be 17.9. Removal efficiencies of 1,4-dioxane with different ozonation dosages(2 and 5 mg/L) for 20 min ozonation had been shown 38% and 87% respectively. There was no observation for biological removal of 1.4-dioxane by attached micro-organisms when used(3.1 years and over 5 years) biological activated carbon(BAC) without pretreatment of oxidation were employed. When a combination of ozonation(2 mg/L and 5 mg/L) and BAC process for $10{\sim}30$ min was applied, removal efficiency for 1,4-dioxine increased only $2{\sim}6%$ compared to only applying ozonation. Therefore removal efficiency of BAC process prior to using oxidation was proven to negligible. Consequently, the results presented in this paper provide a better insight into the adsorption performance of 1,4-dioxane. This observation suggests that using virgin activated carbon made of coal is the best selection for removal of 1,4-dioxane in the water treatment for an advanced treatment. It is clear from this research that longer EBCT for ozonation or higher ozone concentration are more effective operation methods for removal of 1,4-dioxane than longer EBCT in the BAC process.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.7
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• pp.699-705
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• 2010

In this study, three different biological activated carbons (BACs) were prepared from activated carbons made of each coal (F400, Calgon), coconut (Samchully) and wood(Pica, Picabiol) which were run for two and half years in the pilot plant. The attached bio-film microorganisms in and on the BACs were isolated and identified. The results showed that nine different bacteria species (Chryseomonas luteola, Stenotrophomonas maltophilia, Pseudomonas vesicularis, Aeromonas hydrophila, Spingomonas paucimobilis, Agrobacterium radiobacter, Pseudomonas fluorescens, Spirillum spp., and Pasteurella haemolytica) were isolated and identified, the dominant species was Pseudomonas sp. that had occupied 56.5%. More specifically, it was observed that the populations of the microorganisms deceased in the order: Pasteurella haemolytica (18.9%) > Chryseomonas luteola (4.0%) > Agrobacterium radiobacter (3.5%) > Aeromonas hydrophila (2.0%) in and on the BACs. After isolating of 9 species of biofilm microorganisms, the growth curve for the biomass was investigated. During 24~96 hours, the biomass has the highest concentration, and activity of the biomass was the best to uptake geosmin as carbon resources. The operation temperatures for investigating the biodegradation of geosmin were set at $4^{\circ}C$ and $25^{\circ}C$. Pseudomonas vesicularis, Pseudomonas fluorescens, Agrobacterium radiobacter and Stenotrophomonas maltophilia played a maior role in removing the target compound as geosmin. However, geosmin was not biodegraded well by Chryseomonas luteola, Spingomonas paucimobilis, and Spirillum spp.. It is also interesting to evaluate kinetics of biodegradability of geosmin. The first-order rate constants for biodegradability of geosmin at $4^{\circ}C$ and $25^{\circ}C$ were $0.00006{\sim}0.0002\;hr^{-1}$ and $0.0043{\sim}0.0046\;hr^{-1}$ respectively. Higher water temperature produced better geosmin removal rates. When concentrations of geosmin increased from 10 to 10,000 ng/L, the rate constants for biodegradability of geosmin increased from 0.0003 to $0.0882\;hr^{-1}$. As described earlier, higher geosmin concentration in the reactor produced higher rate constant.