• Journal of the Korean Wood Science and Technology
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• v.50 no.5
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• pp.315-324
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• 2022

The termicidal activity and chemical components of wood vinegar from two sources of biomass, nipah fruit shells (NFS) and a mixture of shells and fiber (MSF), were evaluated against Coptotermes curvignathus. A no-choice test was carried out to evaluate their termicidal activity using filter paper samples treated with 2.5%, 5.0%, 7.5%, 10.0%, and 12.5% NFS or MSF vinegar. Both wood vinegars exhibited antitermitic activity against C. curvignathus. The results show that increased concentrations of NFS and MSF vinegar significantly increased termite mortality. In particular, the NFS vinegar caused complete mortality and the lowest filter paper mass losses at 2.18% when treated with 12.5% wood vinegar. The most abundant chemical compounds of NFS vinegar were cyclopropanecarbonyl chloride, 2,5-dichlorophenol, 2-propanone, acetic acid, propanoic acid, benzenesulfonic acid, 3,7-dimethyl-6-octenal, and trans-geraniol. Meanwhile, the main compounds in the MSF vinegar were 1,2-ethanediol, formic acid, acetic acid, ethanoic acid, 2-furancarboxaldehyde, phenol, 2-methoxy phenol, and 4-methyl phenol.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.5
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• pp.210-216
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• 2007

Porous nickel membrane far high precision gas filter was prepared by in-situ reduced/sintered process of NiO with an addition of polymer(PMMA; polymethyl methacrylate). It showed that the porosity of Ni membrane was approximately 52%. It is similar to metal membrane which prepared using metal fiber as raw materials. The average pore diameter and porosity of Ni membrane increased as content of added polymer and decreased as elevating reduced/sintered temperature from $800^{\circ}C$ to $1000^{\circ}C$. Increase of porosity at $800^{\circ}C$ was associated with surface diffusion mechanism that leads to initial sintering, while decrease of porosity at $1000^{\circ}C$ was associated with lattice diffusion and grain boundary diffusion.

• KSBB Journal
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• v.21 no.3
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• pp.188-193
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• 2006

A new type of biofilter, a rotating drum biotrickling filter(RDBF), was developed and operated for the removal of styrene from industrial waste gas. The porous polyurethane foam sheet was used as a packing materials for the RDBF and a pure culture of Gram-positive bacterium Brevibacillus sp. SP1 was used as an inoculum. The reactor showed a short start-up period of 18 days, during which uniform biofilms were developed on the packing. During a steady operation at an incoming styrene concentration of $200ppm_v$ and a retention time of 0.5 min, a high and stable removal of styrene over 95% was observed. The maximum elimination capacity was estimated to be $125g/m^3{\cdot}hr$. The outstanding performance was attributed to an efficient gas-liquid mass transfer and the appropriate supply of nutrient solution to the biofilm microorganisms on the packing by the rotation of the drum.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.309-315
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• 2005

Volatile organic compounds (VOCs) and odor materials are major sources of air pollution in Ulsan city, where much chemical plants are located. Therefore, it is necessary to develop a new reactor which can remove VOCs and odor materials effectively and be equipped at the end of pipe easily. A modified reactor (bioscrubber trickling filter, BSTF), which have both characteristics of biofilter and bioscrubber, was developed and tested on its reactivity with several VOCs using two types of media, fiber and activated carbon 4- ceramic(A/C). It was observed that the removal efficiencies of several types of VOCs such as acetaldehyde, ethylalcohol, butanol, diethylamine and triethylamine were up to $95\%$ when they had about 100 ppm of initial concentration and 80 seconds of residence time. Good attachment of microorganisms to both media, where it is thought the reaction efficiency can be determined according to the amount of microorganisms attachment, observed with scanning electron microscopy(SEM). Initial pressure drops of the packed bed with both media were 229 $mmH_2O/m$ at A/C column and 670 $mmH_2O/m$, respectively. However, maximum pressure drop of fiber column during the operation was over 1,647 $mmH_2O/m$. Therefore, it was thought that the fiber material would not suitable to use in the local plant as a packed bed media.

• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.60-64
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• 2023

The manufacturing process of antibody drugs comprises two main stages: the upstream process for antibody cultivation and the downstream process for antibody extraction. The domestic bio industry has excellent technology for the upstream process. However, it relies on the technology of foreign countries to execute downstream process such as affinity chromatography. Furthermore, there are no domestic companies capable of producing the equipment for affinity chromatography. High gradient magnetic separation technology using a high temperature superconducting magnet as a novel antibody separation and purification technology is introduced to substitute for the traditional technology of affinity chromatography. A specially designed magnetic filter was equipped in the bore of the superconducting magnet enabling the continuous magnetic separation of nano-sized paramagnetic beads that can be used as affinity magnetic nano beads for antibodies. To optimize the magnetic filter that captures superparamagnetic nanoparticles effectively, various shapes and materials were examined for the magnetic filter. The result of magnetic separation experiments show that the maximum separation and recovery ratio of superparamagnetic nanoparticles are 99.2 %, and 99.07 %, respectively under magnetic field (3 T) and flow rate (600 litter/hr).

• Journal of Environmental Science International
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• v.18 no.6
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• pp.691-698
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• 2009

Trickling filter has been extensively studied for the domestic wastewater treatment especially for the small scale plants in rural area. The performance of the trickling filter depends on the microbial community and their activity in the biofilms on the media. Nitrification. denitrification, and phosphorus removal of the trickling filter from the wastewater depend on the activity and the amount of the specific microorganisms responsible for the metabolism. For the estimation of the performance of a trickling filter, batch nitrification experiment and fluorescence in situ hybridization (FISH) were carried out to measure the microbial activity and its distribution on the media of the trickling filter. Batch nitrification activity measurement showed that the top part of the 1st stage trickling filter had the highest nitrification activity and the maximum activity was 0.002 g $NH_4$-N/g MLVSS${\cdot}$h. It is thought that higher substrate (ammonia) concentration yields more nitrifying bacteria in the biofilms. The dominant ammonia oxidizer and nitrite oxidizer in the biofilm were Nitrosomonas species and genus Nitrospira, respectively, by FISH analysis. Less denitrifiers were found than nitrifiers in the biofilm by the probe Rrp1088 which specifically binds to Rhodobacter, Rhodovulum, Roseobacter, and Paracoccus. Phosphorus accumulating bacteria were mostly found at the surface of the biofilm by probe Rc988 and PAO651 which specifically binds to Rhodocyclus group and their biomass was less than that of nitrifiers.

• Journal of environmental and Sanitary engineering
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• v.23 no.3
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• pp.9-22
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• 2008

This study was conducted to develop a system that processes harmful gases and dust, which being generated in the production of micro-inorganic fabric. This can be obtained by melt spinning raw materials such as agalmatolite, fluorspar, limestone, silica under high temperature at $1500-1600^{\circ}C$ in a glass recuperator using a dry method by Cyclone Reactor or Envelope Type (ET) type Bag Filter. If the number of the members of Korea Glass Industry Association reaches up to 45, the damage of the harmful gas being generated in recuperator should not be small. In addition, research of existing facilities showed the most of harmful gas treatment facilities which adopt wet treatment or semi-dry treatment process. This was caused the problems for wastewater and the second pollutive materials. Moreover, in the dust collecting facility behind recuperator, it is also problematic that electric dust collector requires enormous initial investment. We have researched various methods to show both economic and efficient new processes for the preventive facilities of recuperator. As the result of the experiments, the removal efficiencies of HF and SOx were 99% and 87%, respectively. Although it was insignificant reaction, a pretty much interesting result that NOx showed an absorption reaction with $Ca(OH)_2$(removal efficiency was more than 25%) was obtained.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.750-756
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• 1996

$TiO_2$ was dispersed in zeolite and glass filter by soaking them in isopropanol solution of titanium tetraisopropoxide and drying in the air, followed by calcination at $500^{\circ}C$. The analysis of chlorothalnoil was carried out by gas chromatograph with an electron capture detector. Chlorothalnoil was degraded photocatalytically over the matrix-supported $TiO_2$ efficiently and could be completely photodegraded after 3hrs. Production were 5.0ppm of $Cl^-$ for $TiO_2$ supported zeolite, 7.5ppm of $Cl^-$ for $TiO_2$ supported glass filter and 2.0ppm of $Cl^-$ for $TiO_2$ powder. But, $CN^-$ was lower than the detection limit irrespective of matrices.

• Journal of the Korean Chemical Society
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• v.8 no.2
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• pp.47-56
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• 1964

When a developed paper partition chromatogram was irradiated by means of the pneumatic tube system of the Korean research reactor (neutron flux: 1.5 ${\times}10^{12}n/cm^2$sec.) the qualitative confirmation of the developed spot on the chromatogram was possible. In the case of an organic halogen compounds (chloro-acid, chloro-ester, iodide, and fluoride) the spot analysis was possible by the present method whereas the same spot could not give the distinct coloring with a common coloring reagents. Filterpaper thickness calibration and activity calibration induced by irradiation of the components of the filter paper, which were a source of erraneous interpretation of the spot, were searched and an average filterpaper calibration method and filter paper activity were improvised to obtain a good qualitative analysis of the spot. Finally the use and applicability of this method for the analysis identification of an organic halogen compound were evaluated. As the filter paper phase an ordinary phase (Whatmann #1, filter paper) and reversed phase (liquid paraffin impregnated) were used.

• Clean Technology
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• v.24 no.1
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• pp.27-34
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• 2018

Catalytic filter has many advantages for the industrial application owing to its bi-functional ability to treat nitrogen oxides and particulate simultaneously. The technical feasibility of using the catalytic filter in the flue gas treatment process will be more promoted if the high porous ceramic sheet filter is utilized. However, it is not easy to prepare the effective catalytic filter using sheet filter as it has less room for catalyst support due to its thin layer. In this study, catalytic filter using a domestic ceramic sheet filter element has been prepared and conducted the experimental evaluation for NO reduction performance. The current sheet filter element shows the low catalytic activity less than 92% conversion for NO concentration 700 ppm at the face velocity $0.02m\;s^{-1}$. This unexpected low catalytic activity seems to be caused by the present of extraordinary large pores from the lack of uniformity in the pore size distribution of the sheet filter. The large pore size of the sheet filter is reduced by composing the smaller powder as its raw material, which presents improvement in NO conversion more than 96%. More improvement is observed showing 98% NO conversion which is applicable to a commercial plant when the catalyst coating layer is expanded by adding the large $TiO_2$ particles during the catalyst preparation. Both of above two methods is regarded as that the broad gates of the larger pores in the coating layer are effectively filled with the proper catalyst. So these results encourage the utilization of sheet filter as a good catalytic filter material with its potential merit of high permeability.