• 제목/요약/키워드: Acid washing

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Improvement of Oxidation-resistance of Graphite by Phosphate (인산 에스테르에 의한 탄소재료의 내산화 증진 효과)

  • 김경자;조광연;박윤창;김태관;정윤중;임연수
    • Journal of the Korean Ceramic Society
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    • v.36 no.5
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    • pp.555-563
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    • 1999
  • Impregnation of phosphorous additiers into graphite bulk was studied with the goal of enhancing the effectiveness of oxidationprotection. In addition graphite acid washing was carried out prior to the impregnation further to improve oxidation resistance. Observation of the oxidation rate for raw graphite(Raw) impregnated graphite with tri-butyl phsophate on raw block(RP) and impregnated graphite on acid-treated graphite(AP) in air are reported. The phsophorus residue adsorbed on the graphite surface at active sites was determined by FTIR, XRS, TGA techniques. AP with tri-butyl phosphate was found to result in both 30% reduction in oxidation rate at 1000$^{\circ}C$ compared to Raw and increase of 120$^{\circ}C$ in oxidation temperature From the samples of oxidation rate of each specimen in Arrhenius plot it can be said that the present oxidation resistance origninates from the change of chemical reaction modesw neigther by acid-washing treatment nor phsophate impregnation

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The Extraction Characteristics of Metal-contaminated Soil by Soil Washing (토양세척기법을 이용한 중금속 오염토양 처리에서 중금속 추출특성)

  • Hwang, Seon-Suk;Lee, Noh-Sup;NamKoong, Wan
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1072-1080
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    • 2005
  • The extraction characteristics of heavy metals(HM) from a contaminated soil at existing lead smelters were investigated with ethylene diamine tetraacetic acid(EDTA), citrate and HCl as washing solutions. EDTA was more effective for Pb than for other heavy metals. As the mol ratio of EDTA/HM increased, the removal efficiency of heavy metals became higher. When the mol ratio of EDTA/HM approached to 6.5, it removed Pb most effectively. Citrate was effective especially in extracting Zn. The removal efficiency of HCl was comparatively high in almost all heavy metals, and at 0.3N concentration it was the highest. After soil washing process by the use of EDTA, the great part of exchangeable fractions and most of heavy metals of weakly adsorbed like carbonate fraction were extracted. For washing with citrate and HCl, four heavy metals showed the similar exchange of chemical partitioning and the exchangeable fractions of Pb which has weakly adsorbed to soil were more increased than before the process. As removal efficiency of citrate washing process depends upon the distribution of non-detrital fractions, so it can be contended that only the amount of non-detrital fractions could be removed from all the heavy metal content. EDTA and HCl could remove most of non-residual fractions in all heavy metals except Zn. As a result of EDTA washing, toxicity characteristic leaching procedure(TCLP) concentration of the processed soil met the USEPA Pb limit of 5.0 mg/L.

Studies on the Detergency Characteristics of Free Fatty Acid in Oily Soil (Part II. Detergency of Particulate Soil) (오염중의 유리지방산이 세척성에 미치는 영향 제2보 고형오염의 세척성)

  • Kim Eun Ok;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.4 no.1_2
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    • pp.43-48
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    • 1980
  • The effect of free fatty acid in fatty soil on the detergency of particulate soil was investigated. Cotton lawn fabric was soiled with the mixture of polmitic acid, hydrogenated fat, paraffin oil and iron oxide black altering the contents of palmitic acid and was laundered with different sur-fastants under various temperature and alkalinity. The rate of soil removal was estimated by means of the spectoometic analysis of iron on the fabric before and after washing. The results of dergency were compared those obtained by reflactance and K/S value from Kubelka-Munk equation which were derived from reflactance measurements.

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A Study on the Purification by Protein Precipitants and Washing of Agar (단백질(蛋白質) 침전제(沈澱制)의 처리(處理) 및 수세(水洗)에 의한 한천(寒天)의 정제(精製))

  • Lee, Ho-Suck;Rhee, Chul;Yang, Han-Chul
    • Korean Journal of Food Science and Technology
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    • v.17 no.5
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    • pp.340-344
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    • 1985
  • In this study, an effective method for purifying of crude agar was attempted, and at the same time, the effect of crude protein and ash contained in impurified agar on the gel strength of the agar were investigated. In order to reduce the content of protein of crude agar, the agar extract was treated with a protein precipitant such as tricholoroacetic acid(TCA) or perchloric acid(PCA), whereas washing with deionized water was applied to decrease the ash content of agar extract. Among the protein precipitants used in the experiment PCA reduced the crude proteins of crude agar most efficiently; addition of 0.01% PCA resulted in the reduction of crude protein content by 3%, and the gel strength of agar thereby increased from 220g/$cm^{2}$ to 402g/$cm^{2}$. High ash content of crude agar was removed by means of washing treatment and it decreased from 8.1% to 2.7%, leading to the gel strength of 530g/$cm^{2}4$.

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Reduction of Radioactive Waste from Remediation of Uranium-Contaminated Soil

  • Kim, Il-Gook;Kim, Seung-Soo;Kim, Gye-Nam;Han, Gyu-Seong;Choi, Jong-Won
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.840-846
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    • 2016
  • Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0.

Separation of Heavy Metals from Metal-EDTA in Spent Soil Washing Solution by using Na2S (Na2S를 이용한 EDTA 토양세척수로부터의 중금속 분리)

  • Oh, Sanghwa;Shin, Won Sik
    • Journal of Soil and Groundwater Environment
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    • v.20 no.7
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    • pp.103-111
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    • 2015
  • Soil washing with ethylenediaminetetraacetic acid (EDTA) is highly effective in the remediation of soils contaminated with heavy metals. The EDTA recycling process is a requisite for reducing the operating cost. The applicability of Na2S addition on the precipitation of heavy metals from the spent soil washing solution and thereby recycling of EDTA was investigated. Addition of Na2S into the single metal-EDTA and the mixed metal-EDTA solutions ([Na2S]/[metal-EDTA] ratio = 30, reaction time = 30 min and pH = 7~9) was highly effective in the separation of Cu and Pb from metal-EDTA complexes, but not for Ni. The Zn removal efficiency varied with pH and slightly increased upto 40% as the reaction time increased from 0 to 240 min which was longer than those for Cu and Pb. Ca(OH)2 was subsequently added to induce further precipitation of Zn and Ni and to reduce the Na2S dose. At the [Na2S]/[metal-EDTA] ratio of 10, the removal efficiencies of all heavy metals excluding Ni were above 98% with the dose of Ca(OH)2 at 0.002, 0.006 and 0.008 g into 100 mL of Cu-, Pb- and Zn-EDTA solutions, respectively. However, Ca(OH)2 addition was not effective for Ni-EDTA solution. A further research is needed to improve metal removal efficiency and subsequent EDTA recycling for the real application in field-contaminated soils.

Effect of Washing on the Loss of Nutrients in Rice (세미(洗米)에 의한 미곡(米穀)의 영양손실(營養損失)에 관한 연구(硏究))

  • Cheigh, Hong-Sik;Ryu, Chung-Hee;Jo, Jae-Sun;Kwon, Tai-Wan
    • Korean Journal of Food Science and Technology
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    • v.9 no.2
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    • pp.170-174
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    • 1977
  • The comparative effect of washing on the loss of nutrients in rice was studied with regard to varieties of Japonica and Indica type and various polishing degrees. Washing procedure was made by usual method for the preparation of cooked rice. The average loss was 1-2% of total solid, 5-7% of protein, 18-26% of calcium, 19-47% of iron, 22-40% of vitamin $B_1$, 11-24% of vitamin $B_2$ and 36-45% of niacin during washing in the 50-90% polished rice of Japonica and Indica varieties. The Indica rice had relatively higher loss of total solid, protein, calcium and iron than that of Japonica rice. The loss of total solid, N-free extract and vitamin in 70% polished rice was lower than that of 90% polished rice. Loss of lysine in 90% polished rice amounted to more than 6% and was higher than the loss of other amino acids.

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Decontamination of Uranium-Contaminated Gravel (우라늄으로 오염된 자갈의 제염)

  • Park, Uk Ryang;Kim, Gye Nam;Kim, Seung Soo;Moon, Jei Kwon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.1
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    • pp.35-43
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    • 2015
  • A large amount of radioactively-contaminated gravel can be produced on the demolition/restoration of facilities related the back end of fuel cycle. However, because of the lacking in basic knowledge for decontamination of radioactive-contami-nated gravel, this study has performed the basic tests using for soil-washing. To find effective decontamination condition, several experiments were carried out for the selection of optimal decontamination agents. Washing by 0.1 M nitric acid was proved to be more effective than that by distilled water or surfactant for decontamination of uranium-contaminated gravel. In addition, crushing/grinding of uranium-contaminated gravel prior to washing was contributed to increase in of removal efficiency of uranium and reduction of decontamination time. The smaller the sizes of crushed gravel was, the more the removal efficiency increased. Also, small the sized particles improved chances for meeting the clearance requirement of the treated gravel.

Loess Dyeing of Soybean Fabrics (대두직물의 황토염색)

  • Lee, Sol;Lee, Shin-Hee
    • Fashion & Textile Research Journal
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    • v.17 no.6
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    • pp.1004-1012
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    • 2015
  • The purpose of this study is to investigate the loess dyeability of soybean fabric using loess as colorants. Recent days, various textile products such as inner wears, sheets and interior goods are manufactured using materials dyed with loess emphasizing its improved metabolism, anti-bacterial, deodorizing properties, and far infrared ray emissions. Soybean fabric was dyed with loess solution according to concentration of loess, dyeing temperature and dyeing time. To improve washing fastness, soybean fabric and dyed soybean fabric with loess were mordanted by mordanting agents such as sodium chloride(NaCl), Acetic acid(CH3COOH) and Aluminium Potassium Sulfate(AlK(SO4)2·12H2O). Dyeability and color characteristics of dyed soybean fabric were obtained by CCM observation. Particle size distribution of loess, the dyeability(K/S) of soybean fabric, morphology and washing durability of loess dyed soybean fabric were investigated. The results obtained were as follows; Mean average diameter of loess was 1.08µm. The main components of loess used in this study were silicon dioxide(SiO2), aluminium oxide(Al2O3), and iron oxide(Fe2O3). The content of these three component was above 75 weight %. The dyeability of soybean fabric was increased gradually with increasing concentration of loess. The optimum dyeing temperature and dyeing time were 90℃ and 60minutes expectively. The fastness to washing according to concentration of loess and mordanting method indicated good grade result as more than 4 degree in all conditions.

Dyeability using Characteristics of Curly Dock (참소리쟁이의 특성을 이용한 염색성 연구)

  • Son, Won-Kyo;Shin, Jung-Sook
    • The Research Journal of the Costume Culture
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    • v.14 no.2
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    • pp.260-270
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    • 2006
  • In this research, the curly dock was used in the process of dyeing for fabrics of the inner wear & the patient wear. Since the curly dock has a pharmacological effect on dermatosis, this study focused on the variety of color and functions of the inner wear fabrics & patient wear fabrics to make the best use of the pharmacological effect of curly dock. With regards to giving a variety of colors and functions in the inner wear, patient wear fabrics, the curly dock dye was used in each treatment conditions on the cotton & silk fabrics. After dyeing, the dyeability, color change, light fastness, washing fastness, perspiration fastness, antibiosis, far infrared emissivity and emission power were evaluated. The evaluation results are as follows; The dyeablity increased from repeated dyeing and, by using the mordant, variety of colors such as skin, mustard, greyish-brown and dark earth colors were conformed to the naked eye. Fe mordant was better than Al on the lightfastness and the washing fastness. The repeated dyeing was found out to have less effect on neither lightfastness nor washing fastness. Both silk and cotton fabrics were graded $3{\sim}4$, since their degree of degradation appeared to be the same in alkali perspiration and acidic perspiration. In the case of silk fabrics mordanted by Al, the rate of declining in both Staphylococcus aureus ATCC 6538 and Klebsiella pneumonia ATCC 4352 were 99.9%. In addition, the antibiosis was enhanced when the mordant was used. The far infrared was 86.6% of emissivity, $3.34{\times}10^2\;W/m^2{\cdot}{\mu}m$ emission power.

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