• 제목/요약/키워드: Concentration Efficiency

검색결과 4,544건 처리시간 0.031초

Effect of Electrolyte Concentration Difference on Hydrogen Production during PEM Electrolysis

  • Sun, Cheng-Wei;Hsiau, Shu-San
    • Journal of Electrochemical Science and Technology
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    • 제9권2호
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    • pp.99-108
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    • 2018
  • Proton exchange membrane (PEM) water electrolysis systems offer several advantages over traditional technologies including higher energy efficiency, higher production rates, and more compact design. In this study, all the experiments were performed with a self-designed PEM electrolyser operated at 1 atm and $25^{\circ}C$. Two types of electrolyte were used: (i) potassium hydroxide (KOH), and (ii) sulfuric acid ($H_2SO_4$). In the experiments, the voltage, current, and time were measured. The concentration of the electrolyte significantly affected the electrolyser performance. Overall the best case was with 15 wt% $H_2SO_4$ at the anode channel and 20 wt% at the cathode channel with. In addition, increasing the difference in concentration of the sulfuric acid had an effect on the diffusion. The diffusion flux became larger when the difference in concentration became larger, increasing electrolyser efficiency without the addition of extra energy.

슬러지-고정상 반응기에서 페놀폐수의 혐기성 처리에 관한 연구 (A Study on the Anaerobic Treatment of the Phenol Wastewater with the Sludge Blanket-Packed Bed Reactor)

  • 안재동;박동일;김재우;장인용
    • 한국환경보건학회지
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    • 제22권3호
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    • pp.72-80
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    • 1996
  • This study was carried to investigate the biodegradability of phenol wastewater in the sluge blanket-packed bed reactor(SBPBR). The reactor consisted of two regions. The lower region was a sludge blanket of 0.5 m height and the upper region was a packed-bed. The phenol and COD concentration of the effluent, the gas production and the composition of gas were measured to determine the performance of the anaerobic wastewater treatment system as the phenol concentration of the influent was increased from 600 to 1800 mg/l. Stable biodegradation of phenol wastewater could be achieved with the anaerobic treatment system from 600 to 1200 mg/l of the influent phenol concentration. But the SBPBR system was getting more serious at 1800 mg/l of influent phenol concentration. At the steady state of the influent phenol concentration of 600-1200 mg/l, the treatment performance showed the phenol removal efficiency of 94.5~96.3%, the COD removal efficiency of 93.3~96% and the gas production of 4.94~9.64 l/day.

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1단 전기집진기에서 난류확산과 2차유동이 입자의 농도분포에 미치는 영향 (Effects of Turbulence Diffusion and Secondary Flows on the Particle Concentration Distribution in Single Stage ESP)

  • 정상현;김상수;김용진
    • 대한기계학회논문집
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    • 제19권9호
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    • pp.2271-2282
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    • 1995
  • Numerical simulations for the effects of secondary flow and turbulence diffusion on the particle concentration distributions have been carried out for the single stage electrostatic precipitator. The electrohydrodynamic secondary flow, particle concentration distribution and collection efficiency have been evaluated as a function of dimensionless parameters such as Re, $N_{end}$, $P_{e}$ x. The results of simulations show that for increasing secondary flow intensity the concentration distribution is drastically deformed and collection efficiency is decreased which is more than due to turbulent diffusion.n.n.

변형 혐기성 여상 반응조에서 교반강도가 유기물 제거효율에 미치는 영향 (Mixing effect on organic removal efficiency in treating low-strength wastewater using a modified anaerobic filter reactor)

  • 정병곤;이헌모
    • 한국환경과학회지
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    • 제5권4호
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    • pp.513-524
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    • 1996
  • Laboratory investigation was conducted to evaluat the mixing effects on organic removal efficiency to treat low-strength synthetic wastewater using modified anaerobic - filter reactor combining anaerobic filter and upflow anaerobic sludge blanket. Using the modified process the low-strength wastewater like municipal sewage could be treated with 85% T-COD removal efficiency at hydraulic retention time of 6 hours. At the constant organic loading of 0.5 kg COD/m 3-day, the organic removal efficiency and effluent COD concentration are increased as influent COD concentration increased from 125 mg/l to 500 mg/l. Mixing effects on organic removal efficiency are evident and optimum mixing speed is found as 50RPM. Placing the granular sludge and media on which slime layer was pre-formed into the reactor seemed to be very effective In achieving short start-up period. Therefore, the steady state was achived after 4 weeks and 1 week based on T-COD and S-COD, respectively.

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Removal Characteristics of Benzene in Dielectric Barrier Discharge Process

  • Chung, Jae-Woo
    • Journal of Korean Society for Atmospheric Environment
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    • 제18권E1호
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    • pp.13-20
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    • 2002
  • The electrical and chemical properties of the dielectric barrier discharge (DBD) process for the benzene removal were investigated. The benzene removal was initiated with the applied voltage higher than the discharge onset value. The removal efficiency over 95 % was obtained at approximately 1.6 kJ lite $r^{r-1}$ of the electrical energy density. The increase of the inlet concentration decreased the removal efficiency. However, the benzene decomposition rate increased with the inlet concentration . While the increase of the gas retention time enhanced the removal efficiency, the decomposition rate decreased. Identification of the optimum condition between the decomposition rate and the removal efficiency is required for field applications of the DBD process.s.

RELATIVE EFFICIENCIES OF YELLOW CAROTENOIDS FOR EGG YOLK PIGMENTATION

  • Balnave, D.;Bird, J.N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권5호
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    • pp.515-517
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    • 1996
  • The relative efficiencies of deposition into egg yolk of apo-carotenoic acid ester(APO-E, CAROPHYLL Yellow) and saponified marigold xanthophylls (MX), in the presence of canthaxanthin (CN), were determined using a wheat-based diet. APO-E was deposited with an efficiency of 50 percent and MX with an efficiency between 13 and 20 percent. The dose response relationship for MX was curvilinear with a decreased efficiency at higher concentrations. Canthaxanthin was deposited with and efficiency of 38 percent, irrespective of the source of yellow xanthophylls, up to a dietary concentration of 5.5 mg/kg. At a dietary MX concentration of 8.3 mg/kg the efficiency of deposition of CN declined to 24 percent. The results confirm that the replacement ratio of MX : APO-E is between 3 : 1 and 4 : 1 depending on the dietary inclusion of marigold pigment.

감압상태에서의 In-Situ Particle Monitor의 성능특성 (Performance Characteristics of In-Situ Particle Monitors at Sub-Atmospheric Pressure)

  • 배귀남
    • 대한기계학회논문집B
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    • 제22권11호
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    • pp.1564-1570
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    • 1998
  • In-situ particle monitors(ISPMs) are widely used for monitoring contaminant particles in vacuum-based semiconductor manufacturing equipment. In the present research, the performance of a Particle Measuring Systems(PMS) Vaculaz-2 ISPM at subatmospheric pressures has been studied. We created uniform upstream conditions of particle concentration and measured the detection efficiency, the lower detection limit, and the size response of the ISPM using uniform sized methylene blue aerosol particles. The effect of particle size, particle velocity, particle concentration, and system pressure on the detection efficiency was examined. Results show that the detection efficiency of the ISPM decreases with decreasing chamber pressure, and with increasing mass flow rate. The lower detection limit of the ISPM, determined at 50 % of the measured maximum detection efficiency, was found to be about $0.15{\sim}0.2{\mu}m$, which is similar to the minimum detectable size of $0.17{\mu}$ given by the manufacturer.

TiO2/UV공정을 이용한 수중 MTBE의 광분해 특성 (Characteristic of Photodegradation of MTBE Using TiO2/UV Process)

  • 류성필;김성수;오윤근
    • 한국환경과학회지
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    • 제13권3호
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    • pp.289-295
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    • 2004
  • The objective of this study is to delineate removal efficiency of the MTBE in solution by $TiO_2$ photocatalytic degradation as a function of the following different experimental conditions: Initial concentration of MTBE, air flow rate in solution, $H_2O_2$ dosage and pH of the solution. Photodegradation rate was increased with decreasing initial concentration of MTBE. The removal efficiency was 82% after 180 min in the case of MTBE concentration of 100 mg/L but 100% after 180 min in the case of 20 mg/L. Removal efficiency was increased with increasing pH, $H_2O_2$ dosage and air flow rate in solution.

동전기-패턴 공정에서 토양내 과산화수소의 거동 이해

  • 박지연;김상준;이유진;양지원
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.191-194
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    • 2004
  • The concentration of hydrogen peroxide in soil and effluent was measured to understand the relationship between the profile of hydrogen peroxide and the removal efficiency of phenanthrene in an Electrokinetic-Fenton process. Electrokinetic phenomena were observed in two different conditions for 1, 2, 4, and 7 days; 3.5% and 10% hydrogen peroxide. The concentration of hydrogen peroxide in soil was high near the anode and decreased towards the cathode due to the direction of electroosmosis. The hydrogen peroxide concentration in effluent increased with time, but the value was lower than the initial. The removal efficiency of phenanthrene at 10% hydrogen peroxide was higher than the case at 3.5%. The removal efficiency after 7 days was high(> 97%) in both cases.

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담체설치가 고질소함유 양돈폐수의 호기발효에 미치는 영향 (Effects of Artificial Filaments Equipped in the Aeration Tank of Aerobic Fermentation System on the Removal Efficiency of Nitrogen of Swine Wastewater Containing High Nitrogen)

  • 손경호;이상락;안정제;권윤정;정태영
    • 한국축산시설환경학회지
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    • 제6권2호
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    • pp.65-72
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    • 2000
  • This study was conducted to investigate the effects of artificial filaments equipped in the aeration tank of aerobic·fermentation system on the removal efficiency of swine wastes which were fermented an aerobically and thus containing high nitrogen. Two aerobic fermentation system each consist4s of 4 tanks ; storage tank, 1st and 2nd aeration tank and settling tank were run before and one or three weeks after equipment of artificial filament in the aeration tanks. Total solids concentration tended to increase by aerobic fermentation in all running periods. However, decreased(P<0.05) total nitrogen concentration was shown three weeks after the equipment of artificial filament. Ammonia nitrogen concentration also largely decreased(p<0.05) in both running periods of one and three weeks after equipment of artificial filaments. These results suggest that the artificial filaments may improve the removal efficiency of nitrogen in swine wastewater containing high nitrogen during aerobic fermentation.

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