• Journal of Environmental Science International
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• v.2 no.4
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• pp.291-297
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• 1993

The COD values and chloride ion concentrations of the Taewha river flowing through Ulsan area were determined along the main stream and the relationships between CODs and chloride ion concentrations were described. The results showed that the middle-upper stream and downstream of the Taewha river were polluted deeply with municipal sewage and self-purification occured in the middle-downstream of the river. When domestic sewage is a main source of pollutants, and is especially the only source of chloride in the stream water, the ratio of COD/[$\textrm{Cl}^{-}$] will be utilizable as a measure of self-purification of the stream.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.21-26
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• 1991

the Bacillus subtilis LY-353 which secretes the protease isolated from seafoods. The opti-mum culture condition for production of protease from B. subtilis LY-353 was as follows ; tem-perature 35$^{\circ}C$ pH 7.5 salt concentration 1.0% The purification steps involved ammonium sulfate fractionation DEAE-Sephadex A-50 column chromatography and Sephadex G-100 gel filtration A 7.33 fold purification and 6.55 yield of protease was obtained from culture broth, The optimum pH and temperature for the enzyme action were pH7.5 and 55$^{\circ}C$ respecti-bely.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.12-17
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• 2006

Natural rivers have water purification functions called Gravel Contact Oxidation Process, which decontaminate river water by biological absorption, oxidation and degradation on riverbed gravels. This function has been developed and applied to many small/medium-sized urban rivers in Japan as one of the direct river water purification methods. However the method hasn't been verified in the tropics, which have different climate conditions and river characteristics. A preliminary experiment carried out at a polluted urban tributary in the outskirts of Kuala Lumpur, Malaysia where an increasing attention has been paid to river environment, showed a good applicability to the tropical conditions as a technically practical water purification measure with some maintenance cares for sludge management.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.925-928
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• 2001

Recently great efforts and investment have been made in order to achieve economical production by applying new methods like minimization of man-Power into construction field. This paper describe the performance of water purification, to which living organisms can adapt, and the physical properties of porous concrete with continuous voids. Although conventional concrete has been regarded as a destroyer of nature, water and air can pass freely through concrete when it is made porous by forming continuous voids. this not only enables plants to vegetables, but also makes it possible for microscopic animals and plants, including bacteria, to attach to and inhabit uneven surface as well as internal voids when the concrete is provided in a natural water area or waterside area. As a result, Porous concrete using recycled aggregate improved the performance of water purification.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.87-87
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• 2013

Sample concentration and purification processes are essential in the bio-analytical and pharmaceutical fields because most bio samples or media are extremely sophisticated. To concentrate and purify specific substances, passive membrane type filters have been utilized, which is driven by size or charge differences between target and others. The traditional and representative method to identify nucleic acid sequences in the complex biosample is gel electrophoresis, which has been worked by size and net charge of molecules. The adsorption phenomena have been also utilized to concentrate and purify biomolecules. This adsorption of biomolecule can be controlled under specific salts and surfaces as well as surface area. To utilize the differences of physical properties of molecules or bio-targets such as virus, bacteria, and cells, the nanotechnologies can be introduced in target concentration, purification, and isolation processes. In here, I'd like to briefly survey typical examples of nanobiotechnologies which are introduced in sample treatment. Also I specifically demonstrate two different simple techniques to concentrate and detect bacteria from the samples using multifunctional silica nanotube (SNT).

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.275-280
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• 2001

Bacteriocin J105 is a proteinaceous inhibitory substance produced by Latococcus latis subsp. lactis j105 isolated from Kimchi. Bacteriocin J105 was purified to homogeneity by the pH-dependent adsorption-desorption method and reverse-phase HPLC from the culture broth of Lactococcus lactis subsp. lactis J105. Purification of bacteriocin J105 resulted in a 1.47-fold increase in the specific activity and the recovery was 1.5%. Its molecular mass measured by the electrophoretic pattern in the sodium, dodecyl sulfate polyacrylamide gel was about 3.4 kDa. It was stable at $121^{\circ}C$ for 15 min at pH between 2 and 4. However, at pH above 5, bacteriocin was rapidly inactivated. Twenty-one residues from the N-terminal portion of bacteriocin J105 were sequenced using sequence analysis of lantibiotics. Bacteriocin J105 showed significant homology with known nisin A from lactic acid bacteria.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.986-988
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• 2002

A plasmid expression vector of pEStxl encoding a mature form of the B chain of the Shiga toxin was constructed without a signal peptide under the control of an inducible n promoter. The encoded protein was purified to 90% by simple heat treatment, and then further purified to 95% by Phenyl-Sepharose and DEAE-Sepharose chromatographies, all in a single day. Accordingly, this expression system and heat treatment could facilitate the rapid purification of gram-scale amounts of the Shiga toxin B subunit from recombinant Escherichia coli cells.

• Journal of the Korean Ceramic Society
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• v.11 no.1
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• pp.23-28
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• 1974

1. Stage crushing by jaw crusher, steel mortar, and ball mill in turn has shown an inclination to increase the distribution of andalusite in coarse particles as well as to increase that of micas in fine particles. 2. Water elutriation was effective for the removal of muscovite and magnetic separation was effective for that of Mg-Fe micas such as biotte and chlorite. The process of concentration and that of purification are diagramatized respectively as follows: Concentration; Raw andalusite${\lightarrow}$Crushing${\lightarrow}$Screening${\lightarrow}$Water elutriation${\lightarrow}$Magnetic separation Purification; Concentrated andalusite${\lightarrow}$Calcination${\lightarrow}$Ball milling${\lightarrow}$Screening${\lightarrow}$Water elutriation${\lightarrow}$Magnetic separation${\lightarrow}$Acid washing.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.16-20
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• 2003

Nitrogen(N) and phosphorus(P) in surface streams mainly lead to euthrophication. It aggravates water quality and consequently increases the purification costs. As a resolution of water contamination caused by household drainage through irrigation route by 70% of the 1,300 community residents in Eum-Am Myun, Seo-San city, was implemented biological self-purification method by growing Oenanthe Javanica along the polluted water tunnel. The contaminated water was efficiently purified after passing the dropwort field; DO conc. of effluent water was increased 8.3∼61.9% after through the drop wort field. HRT of experiment system was changed 0.05∼1.50/day. 50% of BOD was eliminated at the range above 12 mg/l of Influent BOD conc. Also, 50% of COD was eliminated at the range above 30 mg/l of Influent COD conc. Finnally, the influent T-N loading at range below 1.5 g/m$^3$/d reduced 50% of Influent T-N conc., and so did influent T-P loading at the range below 0.03 g/m$^3$/dwas reduced 50% of Influent T-P conc.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.336.1-336
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• 2002

Recently, mixers are being widely used in the water purification plant in order to increase the filtration efficiency. The cause of an excessive vibration of a base structure to which the mixers are supported, has been evaluated through modal analysis on the mixer shaft and vibration measurements during operation. The fundamental natural frequency of the mixer shaft is found to be around 1.8 Hz and the main vibratory frequency around 30 Hz. (omitted)