• Clean Technology
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• v.14 no.3
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• pp.193-203
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• 2008

A surfactant is used to assist the effect of cleaning, dispersibility and adhesion during leather manufacturing process. Existing surfactant for that process includes many hydrophilic groups that may cause problem such as stain, bad water resistance and poor durability, etc. It is potential problem to make high-performance property for future leather market. In this study, we have synthesized the fluorinated surfactant of which property decreases surface tension, increases dispersion, cleaning effect and the better chrome absorption by the high bond energy of C-F to complement weakness that the present alkyl derivative surfactants have. Using fluorinated surfactant, we can confirm that dispersion is increased, chrome absorption ratio is augmented with high osmosis and coherence, chrome content in the tanning waste water is reduced, BOD and COD contents are diminished and physical characteristics are improved.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.93-99
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• 2000

Treatment of shaving scrap, a chrome containing solid scrap generated by leather manufacturing process, has been so far depended on mainly incineration, soil landfill and ocean dumping, which give bad impact on environment and cause pollution. Shaving scrap generates from the mechanical work for controlling the final thickness of leather and its main components are collagen protein and pan of chromium compound. For the purpose of reusing this leather waste as resources, researches in connection with collagen fiber recovery, gelable protein recovery and liquid fertilizer is being speedily progressed. In the experiment, shaving scrap went through wet pulverizing treatment by physical and chemical methods. Then, making the leather sheet evenly, it is mixed with natural latex and every kind of binding materials in the container, and the mixtures were passed through experimental hydraulic press machine and applied to Fourdrinier machine respectively. Lastly, a test for fading out physical strength and properties of multiple-purpose of leather-like material was performed on a continuous leather sheet prepared by the experiment. In result, the physical strength and properties of leather-like material showed noticeable differences according to mixing ratio of binding materials, beating methods and the Ends of binding materials selected, and generally tear strength was the weakest property among others. Also, by the pilot scale experiment in sequence, it was possible to manufacture recycled goods made of soft and hard types of leather-like material with various performances.

• Textile Coloration and Finishing
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• v.5 no.1
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• pp.33-39
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• 1993

This study was to examine the anti-bacteria effect of chrome-tanned garment leathers by various processes to article from hide. Anti-bacterial test by halo test and shake flask method, and pH value measurment are carried out in this study. The results can be obtained as follows: 1. In the soaking process of chrome-tanned garment leathers, it needs more effective anti-bacterial treatment. 2. pH value of samples by various processes has affected to anti-bacteria effect. 3. Chrome used by the tanning and the neutralization process have been found to be the anti-bacteria activity. 4. The dyeing, the fatliquoring and the finishing process has required anti bacteria treatment.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.532.2-532
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• 1986

Alkaline protease which is an important enzyme used in detergents, leather tanning and food industry was produced by alkalophilic bacterium, Bacillus sp. KCTC 1723 isolated from soil. The maximum productivity of the enzyme in alkaline medium containing 1% sodium bicarbonate was obtained by incubating for 3 days at 37$^{\circ}C$. The optimum pH of the enzyme was 11.5 and calcium ion was effective on stabilization of the enzyme at high temperature. The enzyme was not inhibited by metal chelating agent such as El)TA but inhibited by diisopropyl fluorophosphate. Purification of the enzyme was carried out DEAE- and CM-cellulose column chromatographies and molecular weight of the purified enzyme was determined

• Journal of Environmental Impact Assessment
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• v.16 no.1
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• pp.27-33
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• 2007

Hexavalent chromium-contaminated soils are encounted at many unregulated discharge and improper handling of wastes from electroplating, leather tanning, steelmaking, corrosion control, and wood preservation industries. Contamination of hexavalent chromium in the soil is a major concern because of its toxicity and threat to human life and environment. Current technologies for hexavalent chromium-contaminated soil remediation are usually costly and/or cannot permanently prohibit the toxic element from entering into the biosphere. Thus, as an alternative technique, immobilization is seen as a cost-effective and promising remediation technology that may reduce the leachable potential of hexavalent chromium. The purpose of this paper is to develope an immobilization technique for the formation of the geochemically stabilized hexavalent chromium-contaminated soil from the reactions of labile soil hexavalent chromium forms with the added soluble phosphate and chromium reducing agent. From the liquid phase experiment, reaction order of chromium reducing agent, soluble phosphate, alkali solution shows the best removal efficiency of 95%. In addition, actual soil phase experiment demonstrates up to 97.9% removal efficiency with 1:1 molar ratio of chromium reducing agent and soluble phosphate. These results provide evidence for the potential use of soluble phosphate and chromium reducing agent for the hexavalent chromium-contaminated soil remediation.

• Korean Journal of Pharmacognosy
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• v.7 no.1
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• pp.3-13
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• 1976

The hitherto existing gap in the field of chromatographic methods has been filled by the direct coupling of a suitable oven (TAS-oven) with TLC. The sample to be examined is heated either isothermally or linearly within the temperature gradient of $50{\sim}450^{\circ}C$. The volatile and/or thermolytically evolved substances are fractionated on the TLC-layer and subsequently chromatographed under standard conditions. Transport mechanisms from the sample to the TLC-layer, applications of the TAS-procedure and further developments are discussed. Thermofractography, developed from the TAS-procedure, is demonstrated on different groups of natural substances such as alkaloids, amino acids, nucleic acids. nucleosides, nucleotides, triglycerides and other lipids, pyrone glycosides and aglycon. Experimental work and results on the thermolysis of macromolecular natural and synthetic substances, natural polyphenols, tanning agents and leather and the possibilities of differentiating various lignins, carbohydrate and synthetic polymers are reported. Further, it is shown that classical reactions in the microgram range, e.g. zinc dust distillation, sulphur-and selenium dehydrogenation and catalytic dehydrogenation, can be coupled directly with TLC. Also described is a method which allows to investigate the gaseous compounds evolved during thermofractography in the range of up to $450^{\circ}C$. Thermal procedures coupled with TLC open up the following new possibilities for chemical microanalysis: fractionated separation of distillable and sublimable components, fractionated thermolysis and carrying out of thermal reactions in the ultra micro range.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.357-363
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• 2006

Chromium compounds are widely used in diverse industries including pigment manufacturing, painting, metal plating and leather tanning. With the wide uses of chromium, various adverse effects of the compounds on the environment and human health have been reported. Among them, hexavalent chromium [Cr (VI)], which is a carcinogenic heavy metal, has been widely studies. Epidemiological investigations have shown that respiratory cancers had been found in workers who had been occupationally exposed to Cr (VI). In this study, cell toxicity and induction of reactive oxygen species (ROS) by Cr (VI) (1, 2, 4, $8{\mu}M$) in cultured human bronchial epithelial cells were investigated. Exposure of the cells to Cr (VI) led to cell death, ROS increase, and cytosolic caspase-3 activation. The ROS increase was related with the decreased level of GSH. Chromatin condensation and fragmentation were occurred by Cr (VI) when evaluated by DAPI staining or agarose gel electrophoresis of the extracted DNA. Expression of ROS related genes including glutathione S-transferase, heme oxygenase-1, metallothionein were significantly induced in Cr (VI) treated cells. This result suggests the toxicity in cultured cells by Cr (VI) was expressed through the apoptotic process with ROS induction.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7053-7060
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• 2015

In the present work, novel orange peel was extracted with 100%EtOH (ethanol) and fractionated into four fractions namely F1, F2, F3, F4 which were eluted from paper chromatographs using 100%EtOH, 80%EtOH, 50%EtOH and pure water respectively. The crude extract and its four fractions were evaluated for their total polyphenol content (TPC), total flavonoid content (TFC) and radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Their cytotoxic activity using WST assay and DNA damage by agarose gel electrophoresis were also evaluated in a human leukemia HL-60 cell line. The findings revealed that F4 had the highest TPC followed by crude extract, F2, F3 and F1. However, the crude extract had the highest TFC followed by F4, F3, F2, and F1. Depending on the values of $EC_{50}$ and trolox equivalent antioxidant capacity, F4 possessed the strongest antioxidant activity while F1 and F2 displayed weak antioxidant activity. Further, incubation HL-60 cells with extract/fractions for 24h caused an inhibition of cell viability in a concentration-dependent manner. F3 and F4 exhibited a high antiproliferative activity with a narrow range of $IC_{50}$ values ($45.9-48.9{\mu}g/ml$). Crude extract exhibited the weakest antiproliferative activity with an $IC_{50}$ value of $314.89{\mu}g/ml$. Analysis of DNA fragmentation displayed DNA degradation in the form of a smear-type pattern upon agarose gel after incubation of HL-60 cells with F3 and F4 for 6 h. Overall, F3 and F4 appear to be good sources of phytochemicals with antioxidant and potential anticancer activities.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.5
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• pp.17-23
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• 2013

Six-valent chromium ($Cr^{6+}$) is a highly toxic pollutant, supplied in a variety of industrial activities such as leather tanning, cooling tower blowdown, and plating. Herein, we investigated the removal of $Cr^{6+}$ from aqueous phase using low-cost adsorbents. Steel slag, montmorillonite, illite, kaolinite, red mud, and acid treated red mud with 0.5, 1.0, and 2.0 M HCl were used as adsorbent for the removal of $Cr^{6+}$ and the results showed that acid treated red mud with 2.0 M HCl (ATRM-2.0 M) had higher adsorption capacity of $Cr^{6+}$ than other adsorbents used. Accordingly, $Cr^{6+}$ removal by ATRM-2.0 M were studied in a batch system with respect to changes in initial concentration of $Cr^{6+}$, initial solution pH, adsorbent dose, adsorbent mixture, and seawater. Equilibrium sorption data were described well by Freundlich isotherm model. The influence of initial solution pH on $Cr^{6+}$ adsorption was insignificant. The use of the ATRM-2.0 M alone was more effective than mixing it with other adsorbents including red mud, zeolite, oyster shell, lime stone, and montmorillonite for the removal of $Cr^{6+}$. The $Cr^{6+}$ removal of the ATRM-2.0 M was slightly less in seawater than deionized water, resulting from the presence of anions in seawater competing for the favorable adsorption site on the surface of ATRM-2.0 M. It was concluded that the ATRM-2.0 M can be used as a potential adsorbent for the removal of $Cr^{6+}$ from the aqueous solutions.

• Journal of Sericultural and Entomological Science
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• v.21 no.2
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• pp.11-19
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• 1979

This has been carried out how the sericin insoluble fixations of raw silk should be with potassium alum. This is learned from the leather tanning technique which the process works with collagen, a kind of proteins. Former reports had shown such works, however, they did not consider the moisture absorbability after their process reports by using chromium alum, formalin or vinyl acetate grafting. This report, however, paid attention to protect such absorbability as well as sericin fixation, so far it may be useful for plactical use of silk. In order to clear how the sericin is fixed with such chemicals, fundermental mechanism of weding process and chemical reaction against proteins were also discussed. The obtained results of the report are as followings. 1. Alum should not be treated for raw silk with high temperature bath like other reports because such treat induces raw silk to be stiffly after the treat. 2. It is recommended that raw silk should be treated with alum solution at room temperature for more than three hours. Even in this case, the use of only alum with raw silk could to fix sericin some how, but it increased the water proofness of the silk. 3. 1% of alum solution was found to be able to fix the sericin of raw silk. 4. In case we consider only sericin fixations, a combination treat of 1% alum for three hours and 0.5% NaOH for ten minutes method showed the best result. 5. In case we consider sericin insoluble fixation and moisture absorbility, the reversive combination of the above process was found to be the best results. 6. Sericin fixing evidence was shown with drying feature curves of wed each treated silk where we could to analyze how the chemical nature is changed after each treat. 7. Deguming ratio may be obtained up to 4.3% after the alum combination treat with regular raw silk. Such ratio was considered to be good enough for the purpose when the textile is washed with warm soap water. 8. Moisture absorbability of the combination treat of alum and NaOH was found to be good enough as well as non treated silk. 9. The tenacity and elongation of the treated silk did not change even after three month. 10. Above all, this method is considered to be better process than other coloured fixing (tannin method. Cr-alum method) or smell fixing (formalin method. vinyl acetate method).