• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.430-431
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• 2018

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.437-438
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• 2016

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.336-337
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• 2017

• Journal of Environmental Science International
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• v.10 no.4
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• pp.299-304
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• 2001

For the remediation of the contaminated soil with heavy metals, Cd, Cr, Cu, and Pb, the reaction parameters were optimized. Tartaric acid (TA) and oxalic acid(OA) as a washing agent and recovery of metals, The optimum washing conditions of TA and OA were in the ratio of 1 : 20 between soil and acid solution during 2hr reaction under unbuffered pH solutions. At the optimized reaction conditions, the removal efficiencies were compared with that of 0.1 M HCl and ethylenediamine tetraacetic acid(EDTA). TA showed higher efficiency on the removal of Pb than that of EDTA, which established for the remediation of contaminated soil with Pb and Cd metals. The recovery of metal ions from washing solution was achieved by adding calcium hydroxide and sodium sulfide by forming the precipitation of metal hydroxide and metal slfied. Optimum amounts of sodium sulgide and calcium hydroxide were Cd = 25g/$\ell$, Cu = 5~10g/$\ell$ and Pb = 5~10g/$\ell$ for the washing solution of OA and 2~5g/$\ell$ for the washing solution of TA, respectively. The amounts of $Na_2S$ and $CA(OH)_2$ for the tartaric acid was less than that of oxalic acid.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1047-1052
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• 1998

The porous alumina membrane was prepared from aluminum metal(99.8%) by anodic oxidation using DC power supply of constant current mode in aqueous solution of sulfuric, oxalic, phosphoric and chromic acid. Pore size and distribution, membrane thickness, morphology and crystal structure were examined with several anodizing conditions : reaction temperature, electrolyte concentration, current density and electrolyte type. It was found that ultrafiltration membrane was fabricated in electrolyte of sulfuric, and oxalic acid. On the other hand, microfiltration membrane was fabricated in electrolyte of phosphoric, and chromic acid. Also, it was shown that crystal structure of porous alumina membrane prepared in sulfuric, oxalic, and phosphoric acid was amorphous, whereas porous alumina membrane prepared in chromic acid had ${\gamma}$ type of crystal structure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.220-224
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• 1991

Six reagents (water, citric acid, phosphoric acid, oxalic acid, acetic anhydride and maleic anhydride) were evaluated for their effectiveness is degumming rice bran oil. All chemical reagents tested were found to be significantly more effective than water in removing phosphatides from crude rice bran oil. Especially acetic anhydride and phosphoric acid were effective in reducing phosphorous levels (92.5% and 93.3% removeal, respectively). Nonhydratable phospholipids, lysophosphatidyl choline, were removed more effectively by the chemical reagents than by the water degumming. The major phospholipid(PL) components were phophatidyl choline. Oleic, linolieic and palmitic acids were the major fatty acids of PL in rice bran acetone insolubles(AI). The AI recovered by acetic anhydride degumming produced the most stable emulsions. However, the AI obtained from phophoric acid or oxalic acid treatments had very poor emulsifying properties.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.27-32
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• 1988

The almost similar degumming effect was obtained by using oxalic acid instead of phosphoric acid, which also improves waste-water treatment. At this point, solution of Phosphoric, Acetic, Citric, Oxalic, and Nitric acid were used for degumming of rapeseed and soybean oil. Compared with Phosphoric(PA) and Oxalic acid(OA) were showed a simillar degumming effect in these vegetable oils. In rapeseed oil of 85% PA treating group and 5,10% OA fretting group, residual soap and phosphorus content in neutralized oil, color in bleached oil, and peroxide value and fatty acid content in deodrized oil were showed to simillar result. Soybean oil as well as rapeseed oil were showed to similar result. As a result, we could comfirmed substitutive possibility, which change PA into OA as a degumming agent. In the other hand, waste waters were obtained from 55% PA treating group and 10% OA treating group. Analytical result for this waste waters has showed a wide difference, especially in the BOD and COD. The amount of treating agents and time required in the precipitation seperation and chemical treatment each 3 and 1.7 times, which is PA treating group than OA treating group. We have investigated both the simillar degumming effect by OA solution and an alternative the pollution program means of a chemical treatment process is not possible.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.490-497
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• 2011

In this study, we determined optimal conditions for simultaneous saccharification and fermentation (SSF) using corncob biomass pretreated with oxalic acid. The effect of SSF temperature ($25.8{\sim}34.2^{\circ}C$) and agitation speed (80~220 rpm) were significant at a 99% confidence level in its effect on ethanol production. The highest ethanol production was expected when SSF was performed at $30^{\circ}C$, 170 rpm (22.5 g/L). The ethanol production was improved by mixture of yeast extract (1.25 g/L) and urea (1.25 g/L) as nitrogen source. However, addition of trace metal components and vitamin for SSF was not affected in the ethanol production. Optimal concentration of $KH_2PO_4$, $MgSO_4{\cdot}7H_2O$ for SSF was 1 g/L, 0.25 g/L respectively.

• Journal of the Korean Wood Science and Technology
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• v.40 no.6
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• pp.389-396
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• 2012

In this study, we investigated the kinetics of acid-catalyzed hydrolysis of xylan over a 60 min at $120^{\circ}C$. Sulfuric, oxalic and maleic acids were used as acid catalyst for hydrolysis. The calculated degradation rate constants ($k_1$) showed a correlation with the acid concentration, meaning that the stronger the acid, the higher the xylan degradation rate. Among sulfuric, oxalic and maleic acid catalyzed hydrolysis, the xylan degradation rate to xylose was highest with sulfuric acid. At equivalent solution pH, acid catalyzed hydrolysis was proportional to $H^+$ concentration. The $k_1$ of dicarboxylic acid such as oxalic and maleic acid was higher than that of sulfuric acid at same pH values during hydrolysis.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.15-21
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• 2000

In chlorine dioxide delignification and bleaching the formation of chlorate is undesirable because it does not react with lignin and is harmful to the environment. Chlorate is mainly formed from the in-situ generated hypochlorus acid which is also the main reason for AOX formation. In previous literature scavengers of hypochlorous acid such as sulfamic aicd, DMSO, and hydrogen peroxide have been added to bleaching stages to reduce AOX formation but less attention has been paid to chlorate reduction. This paper thus focuses on the reduction of chlorate content caused by the following additives, sulfamic acid, DMSO, hydrogen peroxide, and oxalic acid. The results show that only sulfamic acid and DMSO reduce chlorate formation under our chlorine dioxide prebleaching conditions. Results by UV spectroscopy and pH adjustment show that scavengers react with hypochlorous acid much faster than with chlorine. Hydrogen peroxide and oxalic acid react with HClO/$Cl_2$much slower than DMSO and sulfamic acid do. The reason for the ineffectiveness of hydrogen peroxide and oxalic acid is ascribed to their slow reaction rates with HClO compared to that of chlorate formation. The fact that only 30-35% of the chlorate can be reduced by sulfamic acid and DMSO when charged in same mole ratio to chlorine dioxide, suggested that the reaction rate of DMSO and sulfamic acid with hypochlorous aicd are of the same magnitude as that of chlorate formation.