• 제목/요약/키워드: Chemical washing

검색결과 348건 처리시간 0.035초

Effect of Fumigation on the Strength of Excavated Costumes (훈증처리가 출토복식유물의 강도 변화에 미치는 영향)

  • 채옥자;박성실;안춘순
    • The Research Journal of the Costume Culture
    • /
    • 제12권4호
    • /
    • pp.591-598
    • /
    • 2004
  • This study examines the effects and influences of fumigation using chemical composite of Methyl Bromide and Ethylene Oxide on the change of strength of excavated dresses. The fabric strength immediately after washing and fumigation increased slightly, but it decreased greatly as the time progressed. The strength of the test sample from Museum A showed a steady decrease with time, while that of Museum B decreased rapidly 5 months later. Compared with the non-fumigated sample, fumigated sample was greater in strength regardless of the time progression, and the strength of sample kept in the exhibit hall was greater than that kept in the storage room. The strength of the fumigated sample was almost same regardless of the three different time periods, before washing, after washing and immediately after fumigation, and it decreased steadily with time, whereas the non-fumigated sample became much weaker in its strength in 10 months after washing. Even 5 months later, the fumigated sample was about as strong as immediately after fumigation, but the strength dropped to a great extent 10 months later.

  • PDF

CHEMICAL DECONTAMINATION OF SOIL CONTAMINATED WITH Cs-137

  • H. J. Won;Kim, G. N.;C. H. Jung;Park, W. K.;Kim, M. G.;W. Z. Oh;Park, J. H.
    • Proceedings of the Korean Radioactive Waste Society Conference
    • /
    • 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
    • /
    • pp.83-95
    • /
    • 2004
  • The removal efficiency of several washing agents on the $Cs^+$ ion was investigated. Leaching of $Cs^+$ ion from the soil surface by washing agents is affected by the exchange capability of the washing solution. Reuse tests of the effective soil washing agents such as $BaCl_2$, NaOH, citric acid+ $HNO_3$ and oxalic acid were performed. NaOH, citric acid + $HNO_3$ and oxalic acid solutions can be reused after passing through the ion exchange column. Among the tested solutions, both of citric acid+ $HNO_3$ and oxalic acid were effective for the decontamination of TRIGA research reactor soil. The radioactivity of soils can be reduced to a release level by the successive application.

  • PDF

Comparative study on the efficiency of pesticide residue removal in foods (Perilla Leaves, Strawberries, Apples)

  • Seung-Woon Myung
    • Analytical Science and Technology
    • /
    • 제37권1호
    • /
    • pp.1-11
    • /
    • 2024
  • In agricultural households cultivating vegetables and fruits, the use of various pesticides to protect crops from diseases and pests or to control weeds is widely practiced enhancing quality and productivity. However, pesticides can pose a threat to consumer health by remaining on the food surface or migrating into the food interior. Households commonly peel off skins, wash with water, or use chemical methods to remove foreign substances including residual pesticides on the food surface. In this study, we measured the washing rate by comparing the pesticide concentrations before and after washing in the leafy vegetable perilla leaves and the fruits strawberries and apples, which were intentionally exposed to pesticides. We compared washing rates using tap water, a baking soda solution, and a commercially available food-specific cleaning solution. The target pesticides for analysis were azoxystrobin, bifenthrin, boscalid, difenoconazole, flubendiamide, and indoxacarb, and the residual pesticide analysis was performed using GC-MS/MS or LC-MS/MS. The removal rates of pesticides were highest with the food-specific cleaner, followed by baking soda and tap water in order.

Fractionation and the Removal of Arsenic-Contaminated Soils Around Dalchĕn Mine Using Soil Washing Process (달천광산 주변 토양 내 비소의 존재형태 및 토양세척법에 의한 제거)

  • Han, Kyung-Wook;Shin, Hyun-Moo
    • Journal of Environmental Science International
    • /
    • 제17권2호
    • /
    • pp.185-193
    • /
    • 2008
  • This study has been carried out to examine the feasibility of soil washing process for reducing arsenic contamination level of soil around $Dalch\hat{e}n$ Mine. The results of physicochemical tests of the target soil showed that pH was weak alkalic ($pH{\simeq}7.8$), soil texture was coarse sand, and organic contents (5.7%) and CEC (Cation exchange capacity; 21.5 meq/100 g) were similar with those of soils generally found in Korea. Contamination levels of arsenic were found to over 201 mg/kg which exceed the Korea standard levels of countermeasure and concern. To investigate chemical partitioning of heavy metals, sequential extraction procedures were adopted and it was found that arsenic was predominantly associated with the residual fraction among five fractional forms as much as over 85%, which is demonstrating that only less than 15% of all might be vulnerable to a selected washing agents. Among 6 kinds of washing agents applied on the screening for arsenic-contaminated soil, HCl and $H_3PO_4$ solution were selected as promising washing agents. In comparison with HCl and $H_3PO_4$ solutions for arsenic washing by kinetic experiment in the change of pH, soil-solution ratio, temperature, and washing solution concentration, $H_3PO_4$ solution was determined to best one of agents tested, which showed faster washing rate than HCl to accomplish regulatory goal.

Washing Efficiency of Blood-Soiled Fabrics in Various Conditions of Washing - Focus on Washing Temperature, Fiber Type and Blood Aging - (혈액오구의 세척성에 관한 연구 - 세탁온도, 섬유종류 및 혈액의 노화를 중심으로 -)

  • Byeon, Hye Jin;Kim, Hye Jin;Myeong, Jeong Eun;Jo, Hee Ryeong;Yun, Changsang
    • Fashion & Textile Research Journal
    • /
    • 제22권4호
    • /
    • pp.534-539
    • /
    • 2020
  • Experimental research is needed to provide information on the removal of bloodstains since washing clothes contaminated with blood is necessary for medical related fields (such as ambulance workers and doctors) as well as for women of childbearing age. This study investigated efficient washing conditions for the removal of bloodstains with a focus on washing temperature, fiber type and blood ageing time. Polyester/cotton fabric showed the highest detergency from among three fabrics that were influenced by the composition of the fiber and the structure of the yarn and fabric. When examining the effect of detergent, it was concluded that the alkalinity over pH 10 was essential to remove bloodstains and that auxiliary agents such as soil antiredeposition agents and bleach had a significant effect on the removal of bloodstains. Washing temperature showed the highest detergency at 20℃ due to the activity of the enzyme without the denaturalization of blood. Blood-ageing influenced detergency by inducing changes in the adsorption area and chemical bond. A combination of methods such as quick removal after contamination, use of alkaline detergents including soil antiredeposition agents and bleach, and low-temperature washing could help remove bloodstains.

Soil Washing Technology for Sr and Cs-contaminated Soil Near Nuclear Power Plants using Calcium and Potassium Based Solutions (칼슘 및 칼륨 용액을 이용한 원자력발전소 주변 스트론튬과 세슘 오염토양 세척기술 연구)

  • Song, Hojae;Nam, Kyoungphile
    • Journal of Soil and Groundwater Environment
    • /
    • 제27권2호
    • /
    • pp.76-86
    • /
    • 2022
  • Calcium (Ca) and potassium (K) were introduced to remove Sr and Cs in soil, respectively. Four factor and three level Box-Bhenken design was employed to determine the optimal washing condition of Ca- and K-based solutions, and the ranges tested were 0.1 to 1 M of Ca or K, L/S ratio of 5 to 20, washing time of 0.5 to 2 h, and pH of 2 to 7. The optimal washing condition determined was 1 M of Ca or K, L/S ratio of 20, washing time of 1 h, and pH of 2, and Ca-based and K-based solutions showed 68 and 81% removal efficiency for Sr and Cs, respectively in soil. For comparison, widely used conventional washing agents such as 0.075 M EDTA, 0.01 M citric acid, 0.01 M oxalic acid, and 0.05 M phosphoric acid were tested, and they showed 25 to 30% of Sr and Cs removal efficiency. Tessier sequential extraction was employed to identify the changes in chemical forms of Sr and Cs during the washing. In contrast to the conventional washing agents, Ca-based and K-based solutions were able to release relatively strongly bound forms of Sr and Cs such as Fe/Mn-oxide and organic matter bound forms, suggesting the involvement of direct substitution mechanism, probably due to the physicochemical similarities between Sr-Ca and Cs-K.

Simple Purification of BA-RGD Protein Based on CaCl2/EDTA Treatment and Inclusion Body Washing (CaCl2/EDTA 및 비이온성 계면활성제 활용 Inclusion Body 정제법을 이용한 BA-RGD 단백질의 생산)

  • Song, Wooho;Byun, Chang Woo;Yoon, Minho;Eom, Ji Hoon;Choi, Yoo Seong
    • KSBB Journal
    • /
    • 제30권6호
    • /
    • pp.291-295
    • /
    • 2015
  • The limited productivity of natural shell matrix proteins has hampered the investigation of their biochemical properties and practical applications, although biominerals in nature obtained by organic-inorganic assemblies have attractive mechanical and biological properties. Here, we prepared a vector for the expression of a fusion protein of a shell matrix protein from Pinctada fucata (named as GRP_BA) with the GRGDSP residue. The fusion protein of BA-RGD was simply produced in E. coli and purified through sequential steps including the treatment with $CaCl_2$ and EDTA solution for cell membrane washing, mechanical cell disruption and the application of non-ionic surfactant of Triton X-100 for BA-RGD inclusion body washing. The production yield was approximately 60 mg/L, any other protein band was not observed in SDS-PAGE and it was estimated that above 97% endotoxin was removed compared to the endotoxin level of whole cell. This study showed this simple and easy purification approach could be applied to the purification of BA-RGD fusion protein. It is expected that the protein could be utilized for the preparation of biominerals in practical aspects.

Effect of Surface Treatment Condition of Aminosilane on Ethylene Polymerization of Supported Metallocene (아미노실란 표면 처리 조건이 담지메탈로센 촉매의 에틸렌 중합에 미치는 영향)

  • Lee, Sang Yun;Lee, Jeong Suk;Ko, Young Soo
    • Korean Chemical Engineering Research
    • /
    • 제53권3호
    • /
    • pp.397-400
    • /
    • 2015
  • The effects of surface treatment method of unreacted N-[3-(trimethoxysilyl)propyl]ethylenediamine (2NS), $N^1$-(3-trimethoxysilylpropyl)diethylenetriamine (3NS), and 3-cyanopropyltriethoxysilane (1NCy) after grafting on the surface of silica and of the surface treatment temperature on ethylene polymerization were investigated. The Zr content of supported catalyst employing filtering method was higher than that of washing method, and the activities of supported catalysts prepared by washing method were higher than those of filtering methods significantly. Regardless of surface treatment methods the activities were in order by $SiO_2/2NS/(n-BuCp)_2ZrCl_2>SiO_2/1NCy/(n-BuCp)_2ZrCl_2>SiO_2/3NS/(n-BuCp)_2ZrCl_2$. The ethylene polymerization activity was increased as the surface treatment temperature of aminosilane on silica increased.

Process Evaluation of Soil Washing Including Surfactant Recovery by Mathematical Simulation (계면활성제 재사용을 포함한 토양 세척 공정의 전산모사 평가)

  • Ahn, Chi-Kyu;Woo, Seung-Han;Park, Jong-Moon
    • Journal of Soil and Groundwater Environment
    • /
    • 제13권1호
    • /
    • pp.32-42
    • /
    • 2008
  • A surfactant recovery and reuse process by selective adsorption with activated carbon was proposed to reduce surfactant cost in a soil washing process. Mathematical model simulation was performed for the whole process, which consists of soil washing, soil recovery, and soil re-washing. The optimal range of surfactant dosage was $6{\sim}10$-fold critical micelle concentration in soil. The efficiency of surfactant reuse process was decreased with increasing the dosage of activated carbon. Effectiveness factor for activated carbon significantly altered the efficiency of the reuse process unlike effectiveness factor for soil. Total requirement of surfactant was reduced to 20-30% with the reuse process compared to the conventional soil washing process. The contamination of wastewater after soil washing was reduced with the reuse process. This mathematical model can be used to estimate performance of the whole process of soil washing including surfactant recovery and to obtain optimal ranges of operating conditions without extra labor-intensive experimental works.

Extraction Characteristics of Heavy Metals for Soil Washing of Mine Tailings-contaminated Soil according to Particle Size Distribution (토양세척공정에서 광미오염토양 입자크기에 따른 중금속 추출특성)

  • Kim, Joung-Dae
    • Applied Chemistry for Engineering
    • /
    • 제19권1호
    • /
    • pp.98-104
    • /
    • 2008
  • This research was performed to evaluate the extraction characteristics of heavy metals for soil washing of mine tailings-contaminated soil according to particle size distribution and the chemical distributional existence of the metals. As the soil particle size was decreased, the extracted concentrations of heavy metals was increased except Fe and Mn. Most of all heavy metals were extracted within 6 h by soil washing with 0.05 M EDTA. Extraction efficiency of metals was decreased for Pb, Cu, and Zn with decreasing of particle size. Significant difference was not observed in extraction efficiency for Cd according to particle size distribution. Extraction efficiency for Cd was the highest as 86~91%, while the lowest as 5~14% for Fe. Most metals of the soil without soil washing was distributed as reducible, oxidizable, and residual fractions. Pb, Zn, and Cd existed as reducible (Fe/Mn oxide) and residual fractions and Cu existed as oxidizable and residual fractions after soil washing treatment with 0.05 M EDTA. As the soil particle size was decreased, residual fraction was increased for Pb and Cu. About 90% of reducible fraction in Pb, Zn, and Cd was removed by soil washing with 0.05 M EDTA. As the results, it was founded that soil particle size was the important parameter to effect on distributional fraction and extraction efficiency of metals in mine tailings-contaminated soil.