• 제목/요약/키워드: particle removal efficiency

검색결과 348건 처리시간 0.03초

정수처리 과정에서의 중금속제거에 관한 연구 (Removal of Heavy Metals Through Conventional Water Treatment Processes)

  • 김중구;고영송;남상호
    • 한국환경보건학회지
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    • 제20권4호
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    • pp.36-44
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    • 1994
  • A study was carried out in order to investigate the removal efficiencies and removal characteristics of heaw metals such as Pb, Cd, Cr, Cu in raw water by one of conventional water treatment processes. The coagulants used in this study were Alum and PAC. Three kinds of water samples were provided: kaolin water, kaolin water mixed with humic acid and raw water from Han River mixed with suspended matter deposited on raw water inlet pipe. Heaw metals were added to the water samples with their respective turbidity, and jar tests were performed. In the results from heaw metal removal studies, lead might be adsorbed or exchanged on the particle surface (SS) rather than react with organic matter added. Cadmium was affected on the dissolved organic matter. Chromium was affected by the both dissolved organic matter and SS concentration, and the restabilization and the enmeshment appeared at moderate (50~80 NTU) and high (100 NTU) turbidity as defined in this experimenL The removal efficiency of copper was relatively little affected by the dissolved organic matter but by SS concentration in comparison with other heavy metals. In these studies as to the raw water turbidities and concentration of heaw metals, it is proved out that the removal efficiency on heaw metals in both cases of PAC and Alum as coagulants was not significantly different.

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전기집진기형 공기청정기의 미세 먼지 저감 특성에 관한 연구 (Characteristics of the Reduction of Fine Particles in an Indoor Air Cleaner Using Electrostatic Precipitation Technique)

  • 목영선;이호원
    • 한국산업융합학회 논문집
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    • 제7권1호
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    • pp.115-120
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    • 2004
  • An indoor air cleaner consisting of a dielectric barrier discharge system and an electrostatic precipitator (ESP) was experimentally investigated. The function of the dielectric barrier discharge is to precharge particles by producing nonthermal plasma before indoor air enters ESP, leading to an enhancement in dust collection efficiency. The dependence of particle size distribution on the plasma discharge was examined to understand the mechanism of the particle precharging. The plasma discharge was found to increase the electrical force of the particles, rather than agglomerate them. Coarse particles in the range of 0.5 to $5.0{\mu}m$ were observed to be easily collected by this indoor air cleaner, and the present study laid emphasis on the removal of fine particles of $0.3{\mu}m$. The collection efficiency of the fine particles was largely enhanced by the plasma discharge.

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PAHs(Polynuclear Aromatic Hydrocarbons)에 오염된 토양 회복공정으로서 마이크로파의 적용성 검토연구 (Applicability on Microwave Technology to the Remediation of PAHs(Polynuclear Aromatic Hydrocarbons) Contaminated Soil)

  • 문경환;변자진;김덕찬
    • 환경위생공학
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    • 제13권3호
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    • pp.102-112
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    • 1998
  • The fate of polynuclear aromatic hydrocarbons(PAMs) in soil has drawn increasing concern due to their toxic, carcinogenic, and mutagenic effects. These compounds have been most commonly carried into the soil in solvent, as in a coal tar or cresote. This study has been focused on the applicability of microwave treatment of soils contaminated by PAHs. Studies have been conducted with soil(particle diameter $150~500{\mu}m$), which was spiked with naphthalene, acenaphthene, fluorene, anthracene and pyrene, with different moisture contents. According to the results of the research, up to 95% removal efficiency of naphthalene was observed in 10% moisturized soil for five minutes microwave inducing And the removal efficiency of acenaphthene and fluorene were observed to be 88.9%, 67.2% in 30% moisturized soil, respectively. Due to the low vapor pressure, anthracene and pyrene showed the low removal efficiency. In case the powdered activated carbon was added to the soil as a sensitizer, anthracene and pyrene were decomposed into a various by-products. Decomposition rates of anthracene and pyrene were increased with incresing addition of a PAC to the soil. It is concluded that the developement of a microwave process to remediate soils contaminated with PAHs is foreseeable. But additional studies are also needed regarding continuous microwave heating process.

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PDMS (Polydimethylsilioxane)-Coated Silica Nanoparticles for Selective Removal of Oil and Organic Compound from Water

  • Cho, Youn Kyoung;Kim, Dae Han;Yoon, Hye Soo;Jeong, Bora;Kim, Young Dok
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.257-257
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    • 2013
  • In order to selectively remove oil and organic compound from water, silica nanoparticles with hydrophobic coating was used. Since silica nanoparticles are generally hydrophilic, removal efficiency of oil and organic compound, such as toluene, in water can be decreased due to competitive adsorption with water. In order to increase the removal efficiency of oil and toluene, hydrophobic polydimethylsiloxane (PDMS) was coated on silica nanoparticles in the form of thin film. Hydrophobic property of the PDMS-coated silica nanoparticles and hydrophilic silica nanoparticles were easily confirmed by putting it in the water, hydrophilic particle sinks but hydrophobic particle floats. PDMS coated silica nanoparticles were dispersed on a slide glass with epoxy glue on and the water contact angle on the surface was determined to be over $150^{\circ}$, which is called superhydrophobic. FT-IR spectroscopy was used to check the functional group on silica nanoparticle surface before and after PDMS coating. Then, PDMS coated silica nanoparticles were used to selectively remove oil and toluene from water, respectively. It was demonstrated that PDMS coated nanoaprticles selectively aggregates with oil and toluene in the water and floats in the form of gel and this gel remained floating over 7 days. Furthermore, column filled with hydrophobic PDMS coated silica nanoparticles and hydrophilic porous silica was prepared and tested for simultaneous removal of water-soluble and organic pollutant from water. PDMS coated silica nanoparticles have strong resistibility for water and has affinity for oil and organic compound removal. Therefore PDMS-coated silica nanoparticles can be applied in separating oil or organic solvents from water.

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NOx 제거용 저온 플라즈마 반응기에서의 플라즈마 화학 및 입자 성장 (The Plasma Chemistry and Particle Growth in the Low Temperature Plasma Reactor for removal of NOx)

  • 김동주;김교선
    • 산업기술연구
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    • 제19권
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    • pp.331-341
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    • 1999
  • We analyzed theoretically the removal efficiency and the particle growth inside the pulse corona discharge reactor to remove $NO_x$ and investigated the effects of process variables such as the NO and $NH_3$ input concentrations. Most of NO is converted into $NO_2$ and $HNO_3$ and the $HNO_3$ reacts with $NH_3$ to form the $NH_4NO_3$ particles. About 6.4% of NO is converted into $HNO_2$ which form the $NH_4NO_2$ particles by reaction with $NH_3$. Some of $NO_2$ follows the reaction pathway to form $NO_3$ and $N_2O_5$. The amount of particles formed inside the reactor is basically determined by the input $NH_3$ concentration. The ratio of NO to $NH_3$ affects the reactor length for particle formation significantly. The higher the input concentrations of NO and $NH_3$ are, the faster the particles grow.

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Post Ru CMP Cleaning에서 연마입자의 흡착과 제거에 대한 chemical의 첨가제에 따른 영향 (Effect of chemical in post Ru CMP Cleaning solutions on abrasive particle adhesion and removal)

  • 김인권;김태곤;조병권;손일룡;박진구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.529-529
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    • 2007
  • Ruthenium (Ru) is a white metal and belongs to platinum group which is very stable chemically and has a high work function. It has been widely studied to apply Ru as an electrode material in memory devices and a Cu diffusion barrier metal for Cu interconnection due to good electrical conductivity and adhesion property to Cu layer. To planarize deposited Ru layer, chemical mechanical planarization(CMP) was suggested. However, abrasive particle can induce particle contamination on the Ru layer surface during CMP process. In this study, zeta potentials of Ru and interaction force of alumina particles with Ru substrate were measured as a function of pH. The etch rate and oxidation behavior were measured as a function of chemical concentration of several organic acids and other acidic and alkaline chemicals. PRE (particle removal efficiency) was also evaluated in cleaning chemical.

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혐기성 유동층 반응기에서 층팽창에 따른 처리특성 및 미생물 부착특성 (A Study on the Characteristics of the Treatment with Bed Expansion and the Biomass Attachment in the Start-up of the AFBR)

  • 안재동;정종식;장인용
    • 한국환경보건학회지
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    • 제21권2호
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    • pp.20-26
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    • 1995
  • The objective of this study is to estimate the effect of the bed expansion and the characteristics of attached biomass in the start-up in the anaerobic fluidized bed reactor(AFBR). The fluidized bed reactor was operated with bacteria supported on the bed of granular activated carbon(GAC). The reactor was operated at 35$\circ$C, 5 kg $COD/m^3\cdot day$ at bed expansion varying from 0 to 100% with soluble glucose wastewater(5,000 mg/l). When the effluent reached a steady state at 100% of bed expansion, maximum COD removal efficiency of 87.3% and 0.031 $m^3CH_4/kg COD_{removed}$ were obtained. At higher bed expansion, COD removal efficiency, methane production rate and biogas production rate increased. Especially, at 50% of bed expansion, the efficiency of the treatment increasedg rapidly in the AFBR. The biomass colonized in the pits and crevices of the GAC particle and no complete biofilm was established in the bioreactor during the experiment.

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전해부상법에서 미세기포와 입자의 기초특성 연구를 통한 제거효율 (A Removal Efficiency from Fundamental Characteristics of Microbubbles and Particles in Electroflotation)

  • 독고석;김원태;한무영;김미경
    • 상하수도학회지
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    • 제19권2호
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    • pp.161-172
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    • 2005
  • Recently, water treatment methods utilizing microbubbles such as DAF and EF are gaining interest and being studied. Current study is focused on the fundamental research of electroflotation by examining the characteristics of microbubbles and particles. The objects of this research consist of two things; (1) theoretical modeling of microbubble-particle collision, (2) the experimental investigation of removal efficiency of turbidity in electroflotation. From investigation, the mechanism of electroflotation can be explained not only by the characteristics of microbubbles and particles but also the chemistry of aluminum dissolved from aluminum electrode during the electroflotation experiment.

적조생물 Cochlodinium polykrikodes 구제효율에 미치는 황토의 광물학적 특징 (Effects of Yellow Clay Contents on Removal Efficiency of Harmful Dinoflagellate Cochlodinium polykrikoides)

  • 박영태;박호섭;박태규;안경호;손문호;김평중;박맹언
    • 수산해양교육연구
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    • 제28권6호
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    • pp.1662-1672
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    • 2016
  • To address physicochemical factors of yellow clay for removing Cochlodinium polykrikoides blooms, the correlation of removal efficiency with mineralogical characteristics of yellow clay collected from various areas was surveyed. Yellow clay from different localities showed the wide range of chemical compositions $SiO_2$ : 43~71%, $Al_2O_3$ : 13~26%, $Fe_2O_3$ : 5~14%, MgO : 0.4~1.8%, $K_2O$ : 0.6~3.3%, L.O.I.(Loss of Ignition) : 4.5~15%. The mineral compositions of yellow clay were mainly consisted of quartz and feldspar including small amounts of kaolinite, chlorite, and Fe-oxides. The result of size analysis showed that $6{\Phi}(31{\sim}16{\mu}m)$ and $7{\Phi}(16{\sim}8{\mu}m)$ were dominated sizes. The zeta-potential were in the range of -4.1~-20.7mV(average -13.7). As increasing removal efficiency of C. polykrikoides, contents of $Al_2O_3$, $Fe_2O_3$ and L.O.I. in yellow clay increased, whereas $SiO_2$ content decreased. Furthermore, the amounts of silt mineral and small particle were high when the removal efficiency was high. According to factor analysis using principle component analysis, two components of factor 1 and factor 2 showed 79% of the total variance, which is related to cohesion and adsorption. Inducing cell lysis of C. polykrikoides by cohension and adsorption between C. polykrikoides and yellow clay.

SiO2/TiO2 혼합입자 슬러리 SiC CMP의 재료제거율 모델링 (Material Removal Rate Modeling of SiO2/TiO2 Mixed-Abrasive Slurry CMP for SiC)

  • 이현섭
    • Tribology and Lubricants
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    • 제39권2호
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    • pp.72-75
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    • 2023
  • Silicon carbide (SiC) is used as a substrate material for power semiconductors; however, SiC chemical mechanical polishing (CMP) requires considerable time owing to its chemical stability and high hardness. Therefore, researchers are attempting to increase the material removal rate (MRR) of SiC CMP using various methods. Mixed-abrasive CMP (MAS CMP) is one method of increasing the material removal efficiency of CMP by mixing two or more particles. The aim of this research is to study the mathematical modeling of the MRR of MAS CMP of SiC with SiO2 and TiO2 particles. With a total particle concentration of 32 wt, using 80-nm SiO2 particles and 25-nm TiO2 particles maximizes the MRR at 8 wt of the TiO2 particle concentration. In the case of 5 nm TiO2 particles, the MRR tends to increase with an increase in TiO2 concentration. In the case of particle size 10-25 nm TiO2, as the particle concentration increases, the MRR increases to a certain level and then decreases again. TiO2 particles of 25 nm or more continuously decreased MRR as the particle concentration increased. In the model proposed in this study, the MRR of MAS CMP of SiC increases linearly with changes in pressure and relative speed, which shows the same result as the Preston's equation. These results can contribute to the future design of MAS; however, the model needs to be verified and improved in future experiments.