• 상하수도학회지
• /
• 제19권3호
• /
• pp.323-329
• /
• 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.

• 한국입자에어로졸학회지
• /
• 제12권4호
• /
• pp.161-168
• /
• 2016

The purpose of this study is to determine the performance characteristics of the paint particulate and volatile organic compounds(VOCs) simultaneous removal from the spraying paint booth in the laboratory and real site by sticky paint particulate and VOCs simultaneous removal demonstration unit. The sticky paint particulate and VOCs simultaneous removal unit is composed of the horizontal type pleated filter modules and the zig-zag type granular activated carbon packing modules. The test conditions at the laboratory are $50.15g/m^3$ of average paint aerosol concentration and 300 ppm of VOCs concentration which were same as the working conditions of spraying paint booth in the real site. But, the demonstration conditions at the real site are varied according to the working condition of spraying paint booth for the kind of passenger car bodies. The test results at the laboratory obtained that 99% of total particulate collection efficiency at 0.62 m/min of filtration velocity and 84% at 1.77 m/min of filtration velocity. The VOCs removal efficiencies are 97% at $3500hr^{-1}$ of gas hour space velocity and 59% at $10,000hr^{-1}$ of gas hour space velocity. In the real site test, the average removal efficiency of PM10 was measured to be 99.65%, the average removal efficiency of PM2.5 was 99.38%, the average removal efficiency of PM1 was 98.52%, and the average removal efficiency of VOCs was 89%.

• 상하수도학회지
• /
• 제32권1호
• /
• pp.55-65
• /
• 2018

It is necessary to develop a mobile water production system in order to provide stable water supply in case of disasters such as floods or earthquakes. In this study, we developed a modular mobile water production system capable of producing water for various uses such as domestic water and drinking water while improving applicability in various raw water sources. The water production system consists of three stages of filtration (sand filtration - activated carbon filtration - pressure filtration) to produce domestic water and an additional reverse osmosis process to produce drinking water. In laboratory and field experiments, the domestic water production system showed excellent treatment efficiency for particulate matter, but showed limitations in the treatment of dissolved substances such as dissolved organic matter. In addition, ultraviolet irradiation was considered as additional disinfection step, because it does not form precipitates of manganese oxides after disinfection. Reverse osmosis process was added to increase the removal efficiency of dissolved substances and the treated water satisfied drinking water quality standards. Fluorescence analysis of dissolved organic matter showed that the fulvic acid-like substances in raw water was successfully removed in the reverse osmosis process. The mobile water production system developed in this study is expected to be used not only in water supply in case of disaster, but also widely used in islands and rural area.

• 청정기술
• /
• 제4권2호
• /
• pp.32-40
• /
• 1998

Polypropylene(PP)과 polyethylene(PE) 분체를 혼합하여 공기정화용 여과재로 사용하기 위한 기공성 고분자 소재를 압출 소결법으로 제조하였다. PP와 PE로 구성된 기공성 고분자 소재는 녹는점이 낮은 PE가 용융되어 PP를 결합시킨 구조임을 주사전자현미경(scanning electron microscope) 분석으로 관찰할 수 있었으며, 고분자 소재의 압출 소결시 압출기 다이 헤드의 온도, 압출 속도, PE의 용융지수 및 첨가량 변화 등에 따른 기공성 고분자 소재의 기계적물성과 여과특성 변화를 시험하였다. 일정한 압출기 헤드 다이 온도와 압출 속도하에서 압출 소결법으로 제조된 기공성 고분자 소재의 여과효율이 PE의 첨가량과는 비례 관계를 나타내었으나 PE의 용융지수에는 반비례 관계를 나타냄을 관찰할 수 있었다. 압출 소결법으로 제조된 기공성 고분자 소재의 여과특성을 시험한 결과, PP와 PE로 구성된 기공성 고분자 소재가 공기정화용 여과재로 적용될 수 있음을 확인할 수 있었다.

• 한국지반신소재학회논문집
• /
• 제5권2호
• /
• pp.31-37
• /
• 2006

본 논문에서 고함수비 슬러지와 퇴적물 탈수에 지오텍스타일 튜브의 이용가능성과 이에 영향을 미치는 요인들에 대한 평가를 수행하였다. 네 가지 고함수비물질을 사용하여 두 가지 지오텍스타일에 대해 다른 두 여과압력으로 실험을 실시하였다. 실험결과, 직포지오텍스타일 튜브는 일반적인 토사보유성기준을 만족하지 않지만 상류측의 필터케익 형성에 의해 세립자의 많은 부분을 유지하였고, 필터케익 형성 후, 투수성은 급속하게 감소하였다. 높은 여과압력은 탈수율을 증가시키는 경향이 있지만 여과효율에는 매우 적은 영향을 미치고, 탈수능력은 지오텍스타일에 관계된 여러 요인에 의해 영향을 받는데 슬러지 재료 자체의 특성이 탈수효율에 지배적인 요소로 나타남을 알 수 있었다.

• 수도
• /
• 통권1호
• /
• pp.9-14
• /
• 1974

• 한국물환경학회지
• /
• 제20권6호
• /
• pp.625-630
• /
• 2004

입상여과는 표준식 정수처리 공정에서 입자물질 제거의 최종공정으로 대부분 사용되고 있다. 따라서 양질의 수돗물을 만들기 위해서는 입상여과에서 높은 수준의 입자물질 제거가 요구되고 있다. 그러나 여과공정에서 모든 입자물질을 제거할 수 없으며, 또한 입자물질의 부착특성은 입자와 용액의 물리화학적 특성에 따라 달라진다. 실험실규모의 여과칼럼과 입경 0.55mm의 유리구슬을 여재로 한 여과실험이 수행되었다. Min-U-Sil 5가 입자물질로 사용되었으며 입자물질을 불안정화하기 위하여 액반을 사용하였다. 운전조건은 표준입상여과와 동일하였으며 여과속도는 5m/h 였다. 입자와 여재가 모두 음의 표면전하를 갖을 경우 작은 표면 전하를 갖는 입자가 여과초기에 여재에 잘 부착되었다. 작은 표면전하를 갖는 입자의 선택적 부착은 유출수의 제타 전위분포를 더 음인 방향으로 이동시켰다. 한편 입자의 표면전하가 양의 값을 갖을 경우는 여과수 입자의 표면전하가 양의 큰 값에서 작은 값으로 변하였는데 이는 입자와 여재사이의 이온전이에 기인하는 것으로 생각된다.

• 한국입자에어로졸학회지
• /
• 제19권4호
• /
• pp.101-110
• /
• 2023

In order to reduce particulate matters (PM) from marine diesel engines, we developed novel electrostatic diesel particulate matter filtration system. Electrostatic diesel particulate filtration (DPF) system consists of electrostatic charger and filtration part. The electrostatic charger and filtration part are composed of a metal discharge electrode and a metal fiber filter (porosity: 68.1-86.1%), respectively. In the electrostatic charger part, diesel soot particles are reduced by electrostatic force. The filtration part after electrostatic charger part reduces diesel soot particles through inertial and diffusion forces. The filtration efficiency of electrostatic DPF system was examined through the experiments using engine dynamometer system (300 kW) and ship (200 kW). The PM reduction efficiencies due to inertial and electrostatic forces showed about 70-75% and 80-90%, respectively, according to the RPM of the engine. The differential pressure of the electrostatic DPF system applied to the ship was about 1-9 mbar, which was less than the allowable differential pressure for ship engines in South Korea (100 mbar). The results show that the electrostatic DPF system is suitable for application to the PM reduction emitted from ships.

• 상하수도학회지
• /
• 제33권1호
• /
• pp.9-16
• /
• 2019

The algal blooms in stagnant streams and lakes have caused many problems. Excessive algae leads to disturbance of ecosystem and overload of water treatment processes. Therefore, phosphorus(P), source of algal blooms, should be controlled. In this study, a filtration trench has been developed to convert dissolved phosphorus into hydroxyapatite(HAP) so that it could be crystallized on the surface of 'phosphorus removal granular material'; and residual particulate phosphorus could be removed by additional precipitation and filtration. The front and rear parts of filtration trench consisted of 'phosphorus removal granular material contact bed' and 'limestone filtration bed', respectively. As a result of the column test using phosphorus removal granular material and limestone serially, $PO_4-P$ was removed more than 90% when EBCT(empty bed contact time) of the contact bed was over 20 minutes; and T-P represented 60% of removal efficiency when total EBCT was over 1.5 hours. The results of column tests to figure out the sedimentation characteristics showed that more than 90% of particulate phosphorus could be removed within 24 hours. It was necessary to optimize the filtration part in order to increase removal efficiency of T-P additionally. Also, it was confirmed through the simulation of Visual MINTEQ that most of particulate phosphorus in the column tests is the form of HAP. Based on the results of the study, it could be suggested that the design parameters are over 0.5 hour of EBCT for phosphorus removal granular material contact bed and over 1.5 hours of EBCT for limestone filtration bed.

• 한국대기환경학회지
• /
• 제31권1호
• /
• pp.54-62
• /
• 2015

Small scale paint overspray booths are being operated nationwidely, for repair of passenger car body parts. paint aerosols are emitted from the paint overspray booth in operations. In paint overspray booth operations without ventilation system and air pollutants collection unit, it may land on nearby equipment. In this study a removal of sticky paint aerosol for application of the small-scale overspray paint booth. it's cause the surface of filter bag from generated sticky paint aerosol. To remove adhesion of paint aerosol the agglomerating agents are injected and mixed with sticky paint aerosols prior to reach the filter bag. The paint spray rate was set as $10{\pm}5g/min$ from air-atomized spray guns in the spray booth, injection rate of agglomerating was $10{\pm}5g/min$ in the mixing chamber. The filtration velocity including air pollutants varied from 0.2 m/min to 0.4 m/min. Bag cleaning air pressure was set as $5.0kg_f/min$ for detaching dust cake from surface of filter bag. Bag cleaning interval at the filtration velocity of 0.2 m/min was around 3 times longer than that of the 0.4 m/min. The residual pressure drop maintained highest value at the highest filtration velocity. Fractional efficiency of 99.952%~99.971% was possible to maintain for the particle size of 2.5 microns. Total collection efficiency at the filtration velocity of 0.2 m/min was 99.42%. During this study we could confirm high collection efficiency and long cleaning intervals for the test with filtration velocity of 0.2 m/min indicating an optimal value for the given dimensions of the test unit and test operating conditions.