• Title/Summary/Keyword: chlorine treatment

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Modification of Oxidation Wool Treated with Protease(Part I)-Changes of chemical properties (산화양모의 효소처리에 의한 양모섬유의 개질(제1보)-화학적 성질의 변화-)

  • 김영리;유효선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.7
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    • pp.843-850
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    • 1998
  • The purpose of this study is the investigation of chemical properties of wool treated with oxidants and protease at low temperature. The chemical degradation of the fibers were investigated by measuring $\alpha$-amimo acid contents and FT-IR analysis. In addition, urea-hydrogensulfite solubility was measured to compare to the oxidation and protease treated wool. The results were as follows. 1) By the oxidation of wool, cystine is oxidised to cysteic acid by way of the intermediate oxides, cystine-S-monooxide and cystine-S-dioxide, in the case hydrolysis catalysed by the protease catalyse. Also, $\alpha$-amimo acid contents is increased, and urea-hydrogensulfite solubility was lower than that of untreated wool. This chemical degradation of wool was occurred due to oxidate hydrolysis in the order of permonosulfate>dichloroisocyanuric acid$\geq$chlorine. 2) The chemical degradation of wool was accelerated by the protease treatment of oxidized wool. Oxidation of wool is considered to make the fiber more susceptibled to enzymatic attact by opening disulphide bond within wool. Enzymatic attact was effectively directed to the wool oxidised by permonosulfate.

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Variation of Oak Kraft Pulp Properties by Xylanase Treatment in C/D, P and Z Stage (C/D, P 및 Z단계 표백시 Xylanase처리에 의한 펄프성질의 변화)

  • Kim, Dong-Ho;Paik, Ki-Hyon
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.2
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    • pp.100-109
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    • 1997
  • The objectives of this study was to decrease pollutions of bleaching effluent and was to enhanced brightness of non-chlorine bleached pulps by xylanase treatments. Xylanase cloned Esherichacoli(E. coli) capable of each of endo, exo-xylanase and acetyl-esterase were obtained from Bacillus stearothermophillus. These xylanase was maintained high activity in alkali and high temperature. Especially endo-xylanase would be more active in $60^{\circ}C$ and pH 11. Xylanase pretreatment(X) of unbleached pulp increased brightness, and decreased the degree of delignification. The degree of increase in brightness of pulp due to xylanase pretreatment was similar to non-enzyme treated pulp, regardless of the amount of enzyme added. Therefore, the addition of xylanase of 2 unit was recommended when considering costs of enzyme. The pulp bleached XO sequence had higher brightness and lower Kappa no, than O bleached pulp, while pulp bleached XP sequence had similar brightness and Kappa no. with P bleached pulp. In XOC/D, XOZ and XOP bleaching sequences, brightness and degree of delignification were improved. The C/D and Z stage bleached pulp was good effect on rate of raise in brightness and Kappa no., but P stage bleached pulp had similar level in non-enzyme treated bleaching sequence.

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A Study on Possibility of Bio-coal Manufacturing using High Moisture Agricultural by- Products (고함수율 농업부산물을 이용한 Bio-coal의 가능성에 대한 연구)

  • Kim, Min-Jung;Park, Kyoung-Joo;Lee, Jai-Young
    • Journal of Soil and Groundwater Environment
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    • v.20 no.3
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    • pp.1-6
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    • 2015
  • The rapid industrial development is facing problem due to energy depletion in Korea. So that, it can be necessary to develop alternative energy sources. Alternative energy like biofuels can be produced by using waste fuel, which is ecofriendly. As we know, the organic waste was banned to dump in landfill and ocean dumping. The most practicable method usually used to reduce organic waste is getting feedstuff or composting, considering the discharge characteristics of agricultural by-products waste treatment were selected. In this study, bio-coal was made using agriculture by product. Biocoal was prepared by adding 50 g of uniformly mixture into reactor and was carbonized at low temperatures 210, 220, and 230℃. The time of reaction was 1, 2 and 3 hours. Bio-coal approximately was similar to the standard of solid fuels. Other characteristics of fuel were also studied. The experiments which were analyzed were moisture content and calorific value, ash, chlorine, sulfur and heavy metals analysis as mercury, cadmium, lead, arsenic, and chromium. As a result, bio-coal 220℃, 2 hours was the optimal conditions while heating.

The Study of Characteristics of Electrolytic Water (전해수의 특성에 관한 연구)

  • Lee, Chan-Woo;Bae, Kie-Seo
    • Textile Coloration and Finishing
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    • v.18 no.6 s.91
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    • pp.43-48
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    • 2006
  • Electrolytic water(EW), studied in recent decades in the Japan, Russia and United State of America, have shown promise as a method of disinfection whereby low levels of free chlorine, sodium hypochlorite, or hypochlorous acid may be produced in situ in Nacl-containing solution. These methods have shown promise in destruction of microorganisms in medical, dental environment, and in the agriculture and food industry. A recently EW treatment system was evaluated for reducing scouring agent and other surfactants in the washing and scouring process of textile industry Unfortunately, there is, to my knowledge, no serious studies of the properties of EW for textile industry In order to study the characteristics of EW and confirm the possibility of applications in textile industry processes, the pH, surface activity, penetration force, surface tension, and contact angle of EW was measured under various conditions. In general terms, What all this shows is that there is fundamental difference between the properties of EW and that of distilled water.

A Study on the Stable Operation of High Sodium Hypochlorite Generation (고농도 차아염소산나트륨 발생장치의 안정적 운영에 관한 연구)

  • Cho, Haejin;Na, Chanwook;Ko, Sungho
    • The KSFM Journal of Fluid Machinery
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    • v.20 no.2
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    • pp.69-74
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    • 2017
  • Sodium hypochlorite, used as water disinfectant, is generated by electrolysis of salt. Compared to chlorine gas disinfection, it is free from high-pressure gas regulation and does not generate toxic gas, so it is increasingly used as a safe disinfectant. Despite these advantages, the concentration of sodium hypochlorite decreases with temperature during long-term storage, and the amount of chlorate increases when a large amount is added, it has mainly been applied to small-scale waterworks. To solve this problem, high sodium hypochlorite generation was developed. In this study, the changes of concentration and chlorate of sodium hypochlorite with time has been studied. As a result of the test, it was found that the usable period of sodium hypochlorite produced at a certain temperature or less was increased from 1.5 days to 13 days. Overall, sodium hypochlorite can be applied even in large-scale waterworks, which makes operation more stable and also reduces the disinfection byproducts, thus it contributed greatly to securing water quality.

The Comparative Study of Different Membranes for Electrolytic Cell for the Hydrogen Peroxide Generation (과산화수소 발생을 위한 전해셀용 양성자 교환 막의 비교)

  • You, Sun-Kyung;Kim, Han-Joo;Kim, Tae-Il;Tsurtsumia, Gigla;Park, Soo-Gil
    • Journal of the Korean Electrochemical Society
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    • v.10 no.4
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    • pp.235-238
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    • 2007
  • There is great interest in the applicability of generated hydrogen peroxide to a variety of industrial processes, usually involving oxidation of organics. Hydrogen peroxide is now employed for the bleaching as well as mechanical and chemical treatment in the pulp and paper industries. It addition, it is considered as an agent to displace the traditional alkaline treatments with chlorine-based chemicals. This paper reports a comparative study of $H_2O_2$ electogeneration on gas-diffusion electrode in divided cell with several $Nafion^{(R)}$ proton-exchange membranes, Russian cation-exchange membrane MK-40 and SPEEK membrane. The influence of different PEMs on electro-chemical cell voltage, current efficiency and energy consumption of hydrogen peroxide generation has been studied.

A novel method of surface modification to polysulfone ultrafiltration membrane by preadsorption of citric acid or sodium bisulfite

  • Wei, Xinyu;Wang, Zhi;Wang, Jixiao;Wang, Shichang
    • Membrane and Water Treatment
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    • v.3 no.1
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    • pp.35-49
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    • 2012
  • In membrane processes, various agents are used to enhance, protect, and recover membrane performance. Applying these agents in membrane modification could potentially be considered as a simple method to improve membrane performance without additional process. Citric acid (CI) and sodium bisulfite (SB) are two chemicals that are widely used in membrane feed water pretreatment and cleaning processes. In this work, preadsorptions of CI and SB were developed as simple methods for polysulfone ultrafiltration membrane modification. It was found that hydrogen bonding and Van Der Waals attraction could be responsible for the adsorptions of CI and SB onto membranes, respectively. After modification with CI or SB, the membrane surfaces became more hydrophilic. Membrane permeability improved when modified by SB while decreased a little when modified by CI. The modified membranes had an increase in PEG and BSA rejections and better antifouling properties with higher flux recovery ratios during filtration of a complex pharmaceutical wastewater. Moreover, membrane chlorine tolerance was elevated after modification with either agent, as shown by the mechanical property measurements.

Tribological Properties of Carbon Layers Produced by High Temperature Chlorination in Comparison with DLC Coating (DLC 코팅과 비교된 고온 염소처리에 의한 탄소 막의 Tribological 특성)

  • Choi, Hyun-Ju;Bae, Heung-Taek;Na, Byung-Chul;Lee, Jeon-Kook;Lim, Dae-Soon
    • Journal of the Korean Ceramic Society
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    • v.44 no.7
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    • pp.375-380
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    • 2007
  • Tribological properties of carbon layers produced by high temperature chlorination of SiC ceramic and DLC (diamond-like carbon) coatings produced by ion plating method were investigated and compared. Carbon coatings were produced by exposure of ball and disc type SiC in chlorine and hydrogen gas mixtures at $1200^{\circ}C$. After treatment for 10 h, dense carbon films up to $180{\mu}m$ in thickness were formed. Tribological behavior of newly developed carbon films were compared with that of DLC films. Wear resistance and frictional coefficient of the surface modified ball and disc type SiC were significantly improved compared to an untreated SiC specimen, and also the modified carbon layer had better performance than DLC coatings. Therefore, in this study, the newly developed carbon films have several advantages over existing carbon coatings such as DLC coatings and showed superior tribological performances.

Synthesis of 2-phenylimino-1,3-thiazoline hydrochloride salts (2-Phenylimino-1,3-thiazoline 염산염 유도체의 합성)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Shin, Sun-Ho;Mah, He-Duck
    • The Korean Journal of Pesticide Science
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    • v.5 no.2
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    • pp.13-17
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    • 2001
  • A synthesis of new 2-phenylimino-1,3-thiazolines 2 for the purpose of development of new agrochemical fuugicide was described. Reaction of chlorine with diketene followed by treatment of benzylamine without isolation of intermediate 8a gave ${\gamma}-chloro-{\beta}-keto$ benzylamide 10a. Thioureas 4 obtained from the reaction of methyl isothiocyanate with aniline derivatives were subjected to 10a in acetone solution to afford the corresponding 2-phenylimino-1,3-thiazoline hydrochloric acid salts 2 through unisolable inltermediates 11 and 12. The plausible reaction mechanism including nucleophilic attack of sulfur assisted neighboring nitrogen lone pair electron on phenyl of thiourea 4 was discussed.

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Simulation for the Flowing Water Purification with Spring Shape Inside Chamber (챔버 내측에 스프링형상을 갖는 유수형 자외선 살균장치 시뮬레이션)

  • Jung, Byung-Gyeon;Jeong, Byeong-Ho;Lee, Jin-Jong;Jung, Byeong-Soo
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.411-416
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    • 2010
  • Interest in application of ultraviolet light technology for primary disinfection of potable water in drinking water treatment plants has increased significantly in recent years. The efficacy of disinfection processes in water purification systems is governed by several key factors, including reactor hydraulics, disinfectant chemistry, and microbial inactivation kinetics. The objective of this work was to develop a computational fluid dynamics(CFD) model to predict velocity fields, mass transport, chlorine decay, and microbial inactivation in a continuous flow reactor. In this paper, It describe the how to design optimal UV disinfection device for ground water, BWT and rainwater. Spring shape instrument silver coated located in inner side of disinfection chamber. It make lead the active flowing movement target water and maximize disinfection performance. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method, performed simulation and proved satisfied performance.