• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.952-959
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• 2012

The photocatalytic reactor was designed to have improved efficiency by enhancing a light intensity of photocatalytic reactor using a reflector coated on the surface at the outer radius of annular shaped photocatalytic reactor. The improved photocatalytic reactor performed to treat waste air containing malodor and VOC with the enhanced light intensity, of which the effect on their removal efficiency was investigated. The intensities of illumination of the improved photocatalytic reactor filled with porous silica-based media and nonporous glass bead media carrying photocatalyst were observed to increase by 28.5% and 30.1%, respectively, compared to those of photocatalytic reactor without any reflector. Using the improved photocatalytic reactor filled with porous silica-based media and nonporous glass bead media carrying photocatalyst, the removal efficiencies were enhanced by 2~3% and insignificantly, respectively. The removal efficiencies of the optimized photocatalytic reactor with reflectors, filled with porous silica-based media carrying photocatalyst, were observed to increase by 26% and 60%, compared to those of photocatalytic reactor (i.e., 19% and 53%), without any reflector, filled with nonporous glass bead media carrying photocatalyst, for hydrogen sulfide and toluene, respectively. The roughness of used reflector surface was measured to be ca. four times as big as that of a commercial mirror. However, their removal efficiencies are expected to be enhanced by increasing an light intensity resulting from lowering the roughness of used reflector coated on the improved photocatalytic reactor in the future.

• Analytical Science and Technology
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• v.25 no.1
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• pp.50-59
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• 2012

In this study, the effect of humidity change on DNPH cartridge sampling efficiency for carbonyl compounds (CCs) has been investigated. For this analysis, gaseous standard of 6 different CCs (formaldehyde (FA), acetaldehyde (AA), propionaldehyde (PA), butyraldehyde (BA), isovaleraldehyde (IA), and valeraldehyde (VA)) was calibrated after derivatization with three types of DNPH cartridge products. Their calibration results derived at RH values between 0 and 80% were then compared against liquid phase standards. If the results of our analysis are compared by the RH values between 20 and 80%, the effect of RH can be distinguished between light and heavy CCs. For lighter CCs (like FA and AA), there was no significant change. However, for the ones heavier than PA, there was fairly noticeable increase in relative recovery ratio in RH value between 20 and 80%. Such patterns are seen consistently from all three DNPH products tested for comparison. The results of our analysis suggest that proper correction for RH change may be needed for heavier CCs by the cartridge method.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.105-118
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• 2006

Isolation and Identification of fatty acid and volatile compounds in tuna fish oil were successfully carried out using supercritical carbon dioxide. Samples of the oil were extracted in a 56 ml semi-batch stainless steel vessel under conditions which ranged from 80 to 200 bar and 40 to $60^{\circ}C$ with carbon dioxide flows from 10 ml/min. Volatiles in the oil extracted from the samples with supercritical carbon dioxide were analyzed by gas chromatography, mass detector with canister system. The extracts were contained with various fatty acids, 57.0% of unsaturated fatty acids such as docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA), and 43.0% of saturated fatty acids. The aroma compounds in the oil showed over 129 peaks, of which 100 compounds were identified. Volatile components included 2,4-hepatadienal(fishy), dimethyldisulfide (unpleasant), dimethyltrisulfide (unpleasant) and 2-nonenal(fatty). The isolation efficiency of the volatile compounds from the samples was 99.4% at $50^{\circ}C$ and 200 bar.

• Analytical Science and Technology
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• v.18 no.1
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• pp.43-50
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• 2005

A number of carbonyl compounds including formaldehyde and acetaldehyde are well known for their toxicity and irritancy. Hence, acquisition of both qualitative and quantitative tool for their analysis is essential to resolve issues associated with malodor or indoor pollution. Using HPLC/UV method, we examined various aspects involved in the measurements of formaldehyde in environmental samples. The results of our analysis indicated that its detection was made as low as 0.5 ppb (assuming 5 L of sample volume), while its precision was maintained near 2% in terms of relative standard error (RSE). When the stability of calibration was checked by variability of slope values obtained over long-term period (e.g., one month), its values were found to remain constantly with RSE values of 3%. It was also found that liquid-phase reaction between formaldehyde and DNPH proceed very slowly to attain equilibrium (one and half hour), while requiring adequate amount of DNPH to form their derivatives. The overall results of our study thus suggest that there are a number of factors to consider for the accurate analysis of formaldehyde in ambient air.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.83-91
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• 1997

Phenolic acids are regarded as harmful materials in food and environment science. But recently, regarded as useful materials by their characteristics which bind metal ions and have pharmaceutical effect. It was necessary to remove or recover phenolic acids from solutIon containing phenolic acids. Continuous fixed-bed adsorption was adapted in order to separate phenolic acids from diluted solution and the breakthrough curve was predicted by nonlinear curve fitting method. The larger bed length showed the longer breakpoint time and the slow mass transfer coefficient. Ferulic acid among the phenolic acids was passed through the breakpoint first and the second and. third were p-coumaric acid and gallic acid. These orders were caused by not only ionic strength between adsrobent and adsorbate but also molecular weights.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.22-27
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• 2019

Nail polish is used to decorate nail beautifully however, it contains lots of toxic materials. Generally, Nail polish consists of film-forming agent, colorant, solvent, surfactant and stabilizer. In this study, to replace toxic chemicals to low irritative, eco-friendly ingredients, we prepared 4 kinds of nail polish and tested safety, stability and performance. Nail polish including shellac/gelatin showed best performance in water-resistance, friability and drying time. When cell toxicity test is done by MTT assay, shellac-gelatin nail polish showed over 70% cell viability at $1,000{\mu}g/mL$ whereas control nail polish in market showed 50% cell viability. At 4 weeks temperature stability test, color was stable at low temperature however it needs formulation improvement at higher temperature.

• Clean Technology
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• v.21 no.2
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• pp.108-116
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• 2015

Hydrogen sulfide and ammonia are one of the common malodorous compounds that can be found in emissions from many sewages treatment plants and industrial plants. Therefore, removing these harmful gases from emissions is of significance in both life and industry because they can cause health problems to human and detrimental effects on the catalysts. In this work, pyrolytic carbon blacks from waste tires were used to develop adsorbent with good adsorption capacity for removal of hydrogen and ammonia. Pellet-type adsorbents were prepared by a mixture of carbon black, metal oxide and sodium hydroxide or hydrochloric acid, and their adsorption capacities were estimated by using breakthrough curve of a continuous fixed bed adsorption column at ambient condition. The adsorbent manufactured with a mixture of carbon black, iron oxide(III) and sodium hydroxide showed the maximum working capacity of hydrogen sulfide. For ammonia, maximum working capacity was obtained by the adsorbent manufactured with a mixture of carbon black, copper oxide(II) and hydrochloric acid.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.530-534
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• 1990

A strain of actinomycetes, Thermoactinomyces sp. CH-53, was isolated from manure and composted livestock feces. Actinornycetes-feed additive was prepared with the solid wheat bran medium of Thermoactinomyces sp. CH-53 that grew vigorously on unsterilized poultry feces at $50^{\circ}C$. pH 6.5- 9.5 and moisture content of 55-65% and added at a rate of 1% (wtlwt) to the commercially assorted feed to be fed poultry. The excreted feces contained $10^7-10^8$. Thermoactinomyces sp. CH-53 cells per gram. Poultry feces malodour was got rid of during treatment. The effect on plant growth was evaluated on the basis of the amount of nitrogen as fertilizer under a loading of 0.2g N1600g soillpot. A11 samples were showed a promotion effect for plant growth. The treated poultry feces added from O.lg to 0.4g total nitrogen per 600g soil in a pat increased the growth of Brassica rapa var. perui-ridis.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.110-124
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• 2007

In this study, the control efficiency of odorous compounds was measured from diverse control process units of 14 individual companies located within the Ban-Wall industrial complex of Ansan city, Korea (January to July 2005), To quantify the control efficiency levels of major odorous compounds, we collected odor samples from both the front and rear side of 17 control process units ($N=17{\times}2=34$). If the control efficiency is compared for each of 32 compounds between different process units, wet scrubber (WS) was found to be the most effective unit in terms of the sum of pollutants showing the positive control signals. Although the WS system shows generally a good control pattern for VOC, it is not the case for most index odorous pollutants; only 3 out of 12 index compounds were found to show positive control efficiencies. The results of the study also indicated that the control efficiency differ greatly between different industrial sectors and/or control process types. In the case of leather industry, carbonyl compounds were found to exhibit the highest control efficiency with its values varying from 19 to 90%. On the other hand, in the case of metal production sector, VOC recorded the maximum control efficiency with values varying from 18 to 79%. According to this study, most air pollution control facilities operated in most companies show fairly poor control efficiencies for most malodor compounds. Hence, to obtain best control efficiency of odorous pollutant emission, acquisition of better information on source characteristics and establishment of effective control technologies are highly demanding.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.327-332
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• 1997

This study was conducted to find out the effect for removal of $NH_3$ gas, one of the offensive odor. The removal efficiencies of $NH_3$ gas through zeolie column increased with the decreased percolation velocity. The effect of zeolite colum in removing $NH_3$ gas was influenced by the water content of zeolite and the added amount of zeolite, but was not influenced by the setting method of zeolite. The $NH_3$ gas removing sequence of saturated cation species on zeolite was in order of Ca->Na->$NH_4$ ->Natural->K-zeolite. Consequently the effect of zeolite on $NH_3$ gas removal efficiency is consided by the water content, added amount and saturated cation of the zeolite.