• Title, Summary, Keyword: $UV_{254}$

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Advanced Water Treatment of High Turbidity Source by Hybrid Process of Ceramic Microfiltration and Activated Carbon Adsorption: Effect of Organic Materials in $N_2$-back-flushing (세라믹 정밀여과 및 활성탄 흡착 혼성공정에 의한 고탁도 원수의 고도정수처리: 질소 역세척 시 유기물의 영향)

  • Park, Jin-Yong;Park, Gil-Yong
    • Membrane Journal
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    • v.19 no.3
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    • pp.203-211
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    • 2009
  • In this study, we used the hybrid module that was composed of granular activated carbons (GAC) packing between module inside and outside of tubular ceramic microfiltration membrane for advanced drinking water treatment. Instead of natural organic matters (NOM) and fine inorganic particles in natural water source, modified solution was prepared with humic acid and kaolin. $N_2$-back-flushing of 10 sec was performed per every period of 10 min to minimize membrane fouling and to improve permeate flux (J). As a result, resistance of membrane fouling ($R_f$) decreased and J increased as concentration of humic acid changed from 10 mg/L to 2 mg/L step by step, and finally the highest total permeate volume ($V_T$) could be obtained at 2 mg/L. Then, treatment efficiencies of turbidity and $UV_{254}$ absorbance were excellent above 99.36% and 97.19%, respectively, but that of $UV_{254}$ absorbance for only microfiltration without GAC at 10 mg/L of humic acid was decreased a little as 90.84%.

The Effect of Pre-chlorination on the Coagulation of Microcystis aeruginosa (전염소처리가 Microcystis aeruginosa 응집에 미치는 영향)

  • Lee, Tae-Gwan;Jin, Jung-Sook
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.3
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    • pp.505-510
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    • 2000
  • In this study the effects of pre-chlorination on the coagulation of water which contain Microcystis aeruginosa. were investigated on the laboratory scale. We prepared the sample of $10^5cell/mL$ Microcystis aeruginosa and then applied 0.2, 1.0, 10 mg-Cl/L chlorine on the sample After reaction period(1 minute and 1 hour), each sample was coagulated. As a result, after 0.4 mg-Al/L coagulant dose, turbidities of all samples were below 2 mg-Kaolin/L. Turbidity was not affected by chlorine dose. As the dose of chlorine was increased, the residual aluminum was decreased, but result of $UV_{254}$ was adverse.

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Electrochemical Degradation of Phenol Using Dimensionally Stable Anode (촉매성 산화물 전극을 이용한 페놀의 전기화학적 분해)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.22 no.8
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    • pp.999-1007
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    • 2013
  • Electrochemical degradation of phenol was evaluated at DSA (dimensionally stable anode), JP202 (Ru, 25%; Ir, 25%; other, 50%) electrode for being a treatment method in non-biodegradable organic compounds such as phenol. Experiments were conducted to examine the effects of applied current (1.0~4.0 A), electrolyte type (NaCl, KCl, $Na_2SO_4$, $H_2SO_4$) and concentration (0.5~3.0 g/L), initial phenol concentration (12.5~100.0 mg/L) on phenol degradation and $UV_{254}$ absorbance as indirect indicator of by-product degraded phenol. It was found that phenol concentration decreased from around 50 mg/L to zero after 10 min of electrolysis with 2.5 g/L NaCl as supporting electrolyte at the current of 3.5 A. Although phenol could be completely electrochemical degraded by JP202 anode, the degradation of phenol COD was required oxidation time over 60 min due to the generation of by-products. $UV_{254}$ absorbance can see the impact of as an indirect indicator of the creation and destruction of by-product. The initial removal rate of phenol is 5.63 times faster than the initial COD removal rate.

Phenol Removal Using Oxygen-Plasma Discharge in the Water (산소-플라즈마 방전을 이용한 수중의 페놀 제거)

  • Park, Young-Seek
    • Journal of Environmental Science International
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    • v.22 no.7
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    • pp.915-923
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    • 2013
  • Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ~ 220 V), oxygen flow rate (2 ~ 7 L/min), pH (3 ~ 11), and initial phenol concentration (12.5 ~ 100.0 mg/L) on phenol degradation and change of $UV_{254}$ absorbance were investigated. Absorbance of $UV_{254}$ can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were $5.204{\times}10^{-1}min^{-1}$ and $3.26{\times}10^{-2}min^{-1}$, respectively.

Effects of Recycled Washwater on Pollutant Removal and Particle Characteristics during Coagulation (회수수가 응집공정의 오염물질 제거 및 입자특성에 미치는 영향)

  • 문병현;김승현;박미선;이향인;이강춘
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.955-960
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    • 2002
  • The recycled washwater, which has different water quality and is produced about 5 to 20% of the total water volume treated, affects the unit operation of water treatment, especially coagulation process. However, the effects of recycled washwater on unit operation of water treatment have not been fully investigated. In this study, effects of recycled washwater on coagulation process were investigated to find the optimum coagulation condition by analyzing turbidity, $UV_{254}$, TOC removal efficiencies. In addition, effects of recycled washwater on residual Al after coagulation were studied by analyzing soluble and particulate Al. The size distribution and fractal dimension of coagulated also analyzed. The recycled washwater was lower pH than the raw water. And the recycled washwater had higher $UV_{254}$, TOC and residual Al concentration than the raw water. Residual Al concentration of recycled washwater was about 50 times higher than that of raw water. Optimum coagulant dosages on the blending recycled washwater and the raw water for turbidity, $UV_{254}$ and Al removal were lower than that on the raw water. However, TOC removal increased by increasing coagulant dosage. The size and fractal dimension of coagulated particle produced in the blending recycled washwater were larger, which imply faster settling velocity, than those produced in the raw water only.

Crosslinking Ratio Analysis of Type I Atelocollagen (Type I Atelocollagen의 가교형성비 분석)

  • Ahn, Soo-Jin;Kim, Yo-Sook;Suh, Hwal
    • Journal of Biomedical Engineering Research
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    • v.17 no.4
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    • pp.479-490
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    • 1996
  • To utilize collagen as an implantable biomateriall the mcct widely used bovine skin origin Type I collagen was investigated Pepsin treated, Type I atelocollagen was extracted and crosslinked by the ultraviolet(W) ray with wavelength of 254nm or by various concentrations of glutaraldehyde to produce collagen membranes. The crosslink rates of the specimens were observed by a polarized light microscope, a scanning electron microscope, and a Fourier transform infrared (FT-lR) spectrometer. The followings are concluded 1. The collagen membranes produced by both 2.5% glutaraldehyde solution and 254nm UV ray irra- diation demonstrated similar morphologies on polarized light microscopic and scanning electron microscopic views. 2. The chemical structures of the crosslinked membranes by glutaraldehyde over 2.5% in concentrations revealed similar intensities to that of the UV ray irradiated one in FT-lR investigation. 3. To obtain optimal croulink in bovine stalin origin Type I atelocollagen, 2.5% glutaraldehyde solution or UV ray irradiation with 254nm wavelength is acceptable.

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The Effects of PAC (Powdered Activated Carbon) on Water Treatment Performance of an Immersed Membrane System Using Flat-sheet Membrane Module (평막을 이용한 침지형 막여과시스템에서 고농도 분말활성탄 주입에 의한 수처리성능 개선 효과)

  • Gai, Xiang-Juan;Kim, Han-Seung
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.2
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    • pp.195-201
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    • 2007
  • A submerged flat-sheet membrane separation system integrated with PAC (powdered activated carbon) was used in this research in order to investigate the effects of PAC on the efficiencies of operation and treatment and to evaluate the performance of the system. The experiments were carried out under operating conditions of a filtration rate of 0.38 m/d, water temperature of $20-28^{\circ}C$, and PAC dose of 0 g/L (Run-A) and 20 g/L (Run-B). The influent concentrations of TOC (total organic carbon), $NH_4{^+}-N$ (ammonia nitrogen) and $UV_{254}$ (UV absorbance at 254 nm) were 2.48 mg/L, 1.4 mg/L and 2.53 1/m, respectively. TOC removal of 43.2 and 73.6%, ammonia nitrogen removal of 4.9 and 15.9%, and $UV_{254}$ removal of 20.6 and 31.6% were obtained for Run-A and Run-B, respectively. During an experimental period of 33 days, no change was found in TMP (Run-B), but the TMP in Run-A increased by 5 kPa after 29 days. This research showed that the filtrate quality and the performance efficiency were enhanced when PAC was introduced into the filtration system.

Reduced Post-Chlorine Dosage Required for Disinfection: Improvement with Ozonation and GAC Process (오존 및 입상활성탄 도입시 후염소 주입량 저감효과 분석)

  • Baek, Young-Ae;Joe, Woo-Hyeun;Kim, Jong-Moon;Choi, Young-Jun
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.4
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    • pp.445-452
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    • 2007
  • This study was carried out to examine effect of post-chlorine dosage reduction by ozonation and GAC process in the field plant for 3years in the "G" water purification plant in Seoul. And it is to compare GAC with BAC process in removal effects of TOC, THMs, THMFP, $UV_{254}$. As a result, chlorine dosage of ozonation and GAC(=BAC) is less demand than GAC. Seasonal reduction of chlorine demand is from about 37% to 59% with BAC, and from 24 to 46% with GAC. Higher reduction in BAC could be achieved. The efficiency of chlorine demand reduction with ozonation was depending on the organic carbon removal. $UV_{254}$ concentration is less about 0.13~0.74L/mg.m in BAC than GAC. Therefore, the combination of ozonation and GAC was more effective in reducing post-chlorine than the single GAC. TOC was also monitored, and results show that a linear relationship between TOC and chlorine demand is appropriate under each treatment process. It means that removal of organic matter(TOC) from finished water is necessary to reduce post-chlorine dosage in clear well and to minimize order of chlorine in distribution systems.

Investigation of Treatment Efficiency for Advanced Processes of Water Treatment Plants in Korea (국내 정수장 고도정수처리 공정에서 공정별 처리효율 조사)

  • Mun, Sung-Min;Choi, Suing-Il;Sohn, Jin-Sik;Yoon, Je-Yong
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.323-329
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    • 2005
  • Advanced processes such as ozonation or activated carbon filtration (ACF) in water treatment plants have been used in Korea since 1994. At present, seventeen drinking water treatment plants are currently operating. This survey compares the treatment performance of advanced processes in eight plants which have comparable water quality data. The three parameters (DOC, $UV_{254}$, and $KMnO_4$ consumption) of water quality were selected as an indicator of treatment efficiency. The treatment efficiency of ozonation and ACF processes was found to vary with large deviations in each plant. Treatment efficiency of DOC, $UV_{254}$, and $KMnO_4$ consumption by post ozonation ranged from 3 to 11%, 6 to 33%, and 12 to 28% respectively. On the other hand, for ACF, treatment efficiency of DOC, $UV_{254}$, and $KMnO_4$ consumption ranged from 7 to 38%, 8 to 48%, and 16 to 66% respectively. These large deviations indicate the advanced processes of water treatment plants to be further optimized.

Application of Newly PAC Selection Method Based on Economic Efficiency (경제성을 고려한 새로운 PAC 선정방법의 적용)

  • Kim, Young-Il;Bae, Byung-Uk
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.11
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    • pp.1141-1147
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    • 2006
  • In order to applicate a newly method for powdered activated carbon(PAC) selection based on economic efficiency, PAC adsorption tests were performed for removal of MIB and dissolved organic carbon(DOC) in drinking water supplies. The removal rate of MIB increased when the PAC dose increased. The Coal-based PACs were superior for adsorption of MIB compared to wood-based PACs. PAC adsorption of DOC and $UV_{254}$ were a little different for different PACs and types of raw water, but both were lower than adsorption of MIB. Among the tested PACs, the one called P-1000 was most effective for removal of MIB, DOC and $UV_{254}$. Most of the organics in the tested samples were proven by excitation emission matrix(EEM) results to be fulvic-like materials. Especially, fulvic-like materials, humic-like materials, and soluble microbial byproduct(SMP)-like materials decreased after contact with PAC. P-1000 which had the lowest MIB cost index(MCI) was selected as the optimum PAC for the target water. PAC efficiency and treatability, particle size and distribution, and the cost associated with PAC dosing for MIB removal according to DOC concentration should all be considered before making the final selection of the best PAC for the target water.