• Title/Summary/Keyword: Physical Water Treatment

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Analysis of the sludge thickening characteristics in the thickener using CFD Model (CFD를 이용한 농축조 슬러지의 유출흐름특성 해석)

  • Park, No-Suk;Moon, Yong-Taik;Kim, Byung-Goon;Kim, Hong-Suck
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.5
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    • pp.777-782
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    • 2011
  • The residual treatment facilities in WTP(water treatment plant) play an important role in solid-liquid separation. At present, it is difficult to solve problems related with thickening and dewatering of WTP sludge, and discharging waste water to river. The quantity of residuals generated from water treatment plants depends upon the raw water quality, dosage of chemicals used, performance of the treatment process, method of sludge removal, efficiency of sedimentation, and backwashing frequency. Sludge production by the physical separation of SS(Suspended Solid) occurs under quiescent conditions in the primary clarifier, where SSs are allowed to settle and to consolidate on the clarifier bottom. Raw primary sludge results when the settled solids are hydraulically removed from the tank. In this study, Drawing characteristics of the sludge thickening in the thickener of Water Treatment Plants was simulated by Using CFD(Computational Fluid Dynamics.

Dyeing Properties of PTT Fiber (2) - Effect of Solvent Treatment on Dyeing and Physical Properties of PTT Fiber - (PTT 섬유의 염색성 (2) - 용제 처리한 PTT 섬유의 염색성 및 물성 -)

  • 이두환;정동석;김호정;이문철
    • Textile Coloration and Finishing
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    • v.15 no.4
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    • pp.8-16
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    • 2003
  • Poly(trimethylene terephthalate)(PTT) fiber was pretreated with organic solvent/water solution of various compositions. The organic solvents used in this experiment were benzyl alcohol, n-buthanol, and N,N-dimethylformamide(DMF). Density of the fibers were investigated as a measure of crystallite region. The dye uptake increased in the order of pretreatment with hot water < untreated < 5% benzyl alcohol < 100% benzyl alcohol < 90% benzyl alcohol; hot water < untreated $\risingdotseq$ 5% butanol < 100% beutanol < 90% butanol; hot water $\risingdotseq$ 5% DMF < untreated < 90% DMF < 100% DMF. The dye uptake increases with increase of crystallinity. It seems likely that the recrystallization process during the pretreatment with organic solvent/water solutions leads to an increase in the microvoid and then a large increase in the dye uptake. Also the dyeing rate increased and the dyeing transition temperature decreased with the pretreatments. The results obtained are corresponds with the plasticization of the fiber structure formed during the pretreatrnent.

A Review of Symptom & Rehabilitative Therapy for Patients with the Decompression Sickness (잠수병의 증상 및 재활요법에 관한 문헌적 고찰)

  • Hur, Young-Gu;Hwang, Hyun-Sook
    • Journal of Korean Physical Therapy Science
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    • v.9 no.1
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    • pp.159-166
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    • 2002
  • The purpose of this study was to review the knowledge related to historic background, causes, symptoms, etiology and rehabilitation methods related to this disease and suggest some ways to reduce complications from it. The importance of underwater pressure disease was not emphasized, therefore, there is a need for continuous research on treatment methods and prevention for it. As one goes into the deeper water, they will be affected by the hydraulic pressure rather then the atmospheric pressure, and it will be increased 1mmHg by 10meters. Underwater pressure disease can be occurred when one comes out of deeper water too quicked. This results the imbalance of the composition rate of nitrogen in blood. However, there is not enough facilities to treat this disease and these facilities are located in limited areas. Therefore, there is an urgent need to set up a medial center that is specialized in prevention and treatment of underwater pressure disease.

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The Study on Development of Porous Media for Water Treatment (수처리용 다공성여재의 개발에 관한 연구)

  • 이영신;정상철;홍성철
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.16-20
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    • 1997
  • The purpose of this study is to develop of porous media for water treatment. It was made of porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag (media-s) and humus soil (media-h) with material, only material kaolinite(media-k). In order to examine the characteristics of physical-chemical were used to sem, x-ray. The results of study are given porous size on media-h which was able to water treatment.

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Discussion of Problems During the Application of the On-line Particle Counter In Water Treatment Process (정수처리 공정에서 연속식 입자계수기의 적용성 검토에 관한 연구)

  • Moon, Seong-Yong;Kim, Seung-Hyun
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.2
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    • pp.214-220
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    • 2005
  • Errors may occur due to analysis methods and water quality during the application of the on-line particle counter In water treatment process. Errors caused by analysis methods include particle destruction by shear force due to inflow speed and tube friction, as well as interruption by screening, bubbles and contaminants. Since errors happen frequently because of these factors, it is necessary to examine and evaluate such errors during the application of a particle counter. Errors can be large due to screening and bubbles. Measurement values are effective for water analysis after filtration process. However, because of screening, only measurement values for particles above $7{\mu}m$ are valid for water with a turbidity between 3-10NTU. As particle numbers around $10{\mu}m$ increase a lot after ozone treatment, sufficient pretreatment process is necessary. Physical conditions should keep stable for inflow to decrease errors caused by shear force.

The Physical Method and Examination Regarding to the Psychological Treatment (심리치료에서 물리치료기법과 탐색)

  • Kim, Dong-Dae
    • Journal of Korean Physical Therapy Science
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    • v.2 no.4
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    • pp.807-816
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    • 1995
  • Many kinds of methods for the psychological treatments are performed which are differentdepending on the patient's condition and the clinical character. Therefore, a great deal of good effects can be expected by the intention or knowledge of the carrer, although the patients are under the same symptom. The symptom of pain can be given different meanings considering the professional knowledge. It's the same case when the very same psychological condition can be iudged differently and the way of being treated can be variable. The physical treatment is a kind of method that cures illness or injury using all sorts of factors such as water, electricity, light, and exercises. In general, physical treatment as known to cure the physically tnjuried or the crippled. In this case, taking psychosomatic for example, I examined the idea that many kinds of physical treatments can be used in the field of psychotherapy. What's more, I suggest that the use of those methods be expanded to psychotherapy.

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Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(III) - Effects of types of base paper and surface treatments on physical properties of the base paper for water resistant corrugated board - (농산물 저온유통용 내수 골판지 상자의 제조(제3보) -원지의 종류와 표면처리 방법에 따른 내수 골판지 원지의 물성-)

  • Jo Jung-Yeon;Min Choon-Ki;Shin Jun-Seop
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.2 s.110
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    • pp.70-77
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    • 2005
  • For the purpose of developing liner board for water resistant corrugated board in the cold chain system, several types of base paper for corrugated board were purchased from the market and 6 different boards were produced in the mill by applying the chemicals, chosen in the previous studies, on the base paper. Then water-moisture resistance and physical properties of the boards were compared each other. The liner board which is dried at high temperature with pressure by Condebelt (CK paper) showed a superior performance in strength over common liner boards. Strength of the board increased by surface chemical treatment up to $60\%$ of compressive strength and $30\%$ of burst strength. Starch insolubilization with Ammonium Zirconium Carbonate and surface coating with a surface sizing agent and a moisture resistant chemical on CK paper showed the best result. Therefore this method was recommended to produce the outer liner board for water resistant corrugated board.

Recent Advances in Advanced Oxidation Processes

  • Huang, Chin-Pao
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 1998.10a
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    • pp.1-1
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    • 1998
  • Advanced (Chemical) oxidation processes (AOP) differ from most conventional ones in that hydroxyl radical(OH.) is considered to be the primary oxidant. Hydroxyl radicalcan react non-selectively with a great number of organic and inorganic chemicals. The typical rate constants of true hydroxyl radical reactions are in the range of between 109 to 1012 sec-1. Many processes are possible to generate hydroxyl radical. These include physical and chemical methods and their combinations. Physical means involves the use of high energy radiation such as gamma ray, electron beam, and acoustic wave. Under an applied high energy radiation, water molecules can be decomposed to yield hydroxyl radicals or aqueous electrons. Chemical means include the use of conventional oxidants such as hydrogen peroxide and ozone, two of the most efficient oxidants in the presence of promoter or catalyst. Hydrogen peroxide in the presence of a catalyst such as divalent iron ions can readily produce hydroxyl radicals. Ozone in the presence of specific chemical species such as OH- or hydrogen peroxide, can also generate hydroxyl radicals. Finally the combination of chemical and physical means can also yield hydroxyl radicals. Hydrogen peroxide in the presence of acoustic wave or ultra violet beam can generate hydroxyl radicals. The principles for hydroxyl radical generation will be discussed. Recent case studied of AOP for water treatment and other environmental of applications will be presented. These include the treatment of contaminated soils using electro-Fenton, lechate treatment with conventional Ponton, treatment of coal for sulfur removal using sonochemical and the treatment of groundwater with enhanced sonochemical processes.

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The Effects of Water-Based Exercise on Physiological Cost Index and Balance in Stroke Patients

  • Park, Seung-Kyu;Park, Sam-Heon
    • The Journal of Korean Physical Therapy
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    • v.26 no.6
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    • pp.411-417
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    • 2014
  • Purpose: This study attempts to find the effects of water-based exercise performed on stroke patients in their physiological cost index and static and dynamic balance. Methods: The subjects were 30 stroke patients, who were randomly divided a water-based exercise group and a land-based exercise group, each with 15 patients. Both exercises ware performed 3 day per week, for 40 minutes a day, for a period of eight weeks. Results: The Water-based exercise group showed a decreased physiological cost index compared to the land-based exercise group, with the physiological cost index of the water-based exercise group decreasing, while the land-based exercise group, showing a significant decrease. Water-based exercise increased static and dynamic balance capacity better than land-based group, showing a significant difference and better efficiency of water-based exercise when compared to land-based exercise. Conclusion: From the result of the study, we found that water-based exercise is more effective in improving PCI and static and dynamic balance capacity. Through this study, training in water-based stroke patients could use cardiovascular endurance and buoyancy and the vortex, as an effective treatment that can enhance the growth and voluntary participation in the range of the patient's own movement the thought is, in consideration of the changes in the physiological cost index due to the difference in the ground and water, and should establish a training program that matches the purpose.

Analysis on Occurrence of the Scum in Water Treatment Plants and Its Removal by Water Spray Method (정수장(淨水場) Scum의 발생(發生) 원인분석(原因分析)과 살수에 의한 물리적(物理的) 제거효과(除去效果))

  • Yoon, Jae Heung;Choi, Gye Woon
    • Journal of Korean Society of Water and Wastewater
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    • v.8 no.3
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    • pp.26-33
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    • 1994
  • To slove the problems by the scum, which causes operational and water quality problems in water treatment plants, several researches were conducted based on the site investigations on twelve large water treatment plants, biological and chemical analysis of scum, analyzing raw water quality data. Two types of scum, which are from scum and floe scum, can be classified based on the analysis and site investigations. The major parameter generating floe scum was indicated as fine bubbles dissolved in the water. The fine bubbles dissolved in the water can be generated by over-saturated air in the water, adding aluminum surface as the coagulant, conducting the break point pre-chlorination and so on. The water spray method, which is one of the physical treatment methods for removing scum, was selected for conducting experiments on the removal efficiency in the flocculation basin of the real water treatment plant. The water spray method was successfully applied for removing scum with the advantages of using spiral nozzles in case of using the raw water rather than the cleaned water.

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