• Environmental Engineering Research
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• 제21권2호
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• pp.109-120
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• 2016

Conventional treatment techniques cannot meet the stringent modern water quality regulations emanating from the need to provide high quality drinking water. Therefore, a number of studies have suggested low pressure membrane filtration as a worthwhile alternative. However, a major constraint to the extensive use of this technology in low and middle income countries is the high operating and maintenance costs caused by the inherent predisposition to membrane fouling. Notwithstanding, pretreatment of feed water using techniques such as coagulation, adsorption, oxidation and bio-filtration is believed to control fouling. In this review paper, the existing scientific knowledge on membrane fouling and pretreatment techniques for controlling fouling in low pressure membranes is analyzed with the aim of providing new and valuable insights into such techniques, as well as unveiling crucial issues noteworthy for further studies. Among the techniques reviewed, coagulation was observed to be the most cost-effective and will remain the most dominant in the coming years. Although oxidants and magnetic ion exchange resins can also control fouling, the propensity of oxidants to form health treating precursors and the high economic implications of magnetic ion exchange resins will hinder their adoption in developing countries.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.526-531
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• 2000

Application of electrodewatering (EDW) to mechanical dewatering system was studied to decrease water content in the sludge generated from waste water treatment process. Experiments realized the reduction of water content in the sewage sludge. EDW enhancing the conventional filtration by an electric field is an emerging technology with the potential to improve dewatering. In this study, a piston filter press was constructed, the digested sludges were dewatered by EDW under conditions of DC electric field and constant pressure in the piston filter press. Constant electric field from $0{\sim}120\;V/cm$ and constant pressure $98.1{\sim}392.4\;kPa$ were used. The results showed that as electric field was increased the dewatering rates increased and as pressure was increased the dewatering rates decreased. Also as polymer was added the dewatering rates increased. This experiments produced final sludge cake with water content of 60 wt% using EDW, compared with 80 wt% using pressure filtration alone.

• 한국산업융합학회 논문집
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• 제20권4호
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• pp.339-343
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• 2017

Masks are a portable functional product for daily use. They can protect user health by filtering harmful fine particles in the air. In the past decade, there have been approximately 10 yellow dust incidences per year, amounting to a total duration of 20 days, and they continue to increase year after year. In addition, the frequency of yellow dust incidences in Korea has increased by more than four times compared to levels from the 1970s. Statistical reports indicate that annual damages caused by yellow dust amount to more than six trillion KRW. This study developed a zero-fog multi-layer mask with a collection efficiency and yellow dust and particulate matter filtration areas that are at least thrice as effective as existing masks. The new mask also reduces pressure drag by half.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 제6회 하계 Workshop (98 한국막학회, 국립환경연구원 국제 Workshop, 수자원 보전과 막분리 공정)
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• pp.155-170
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• 1998

1. The flux for hydrophilic CA membrane is higher than that for hydrophobic PES membrane at any operating conditions. The difference in bpth fluxes becomes greater as the water recovery is lower. 2. Backwash pressure should be more than twice as high as filtration pressure in order to maintain the higher flux. Backwash frequency is independent of the flux when the UF is operated under the same water recovery. 3. The relatively lower crossflow velocity of around 0.1 m/s would be appropriate because of the lower energy consumption per treated water. 4. The membrane fouling occurring at high turbidity and high concentration of organic compounds in raw water can reduce the flux and increase the removal of the organic compounds. 5. It is confirmed by the pilot plant testing that the UF by using the CA membrane module was well applicable to the drinking water treatment.

• 대한한방내과학회지
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• 제10권1호
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• pp.125-136
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• 1989

This study was investigated to clarify the effect of Sin Bee Tang (神秘湯) on the renal function, arterial blood pressure and plasma cortisol. The results obtained were follows; 1. Urine volume and glomerular filtration rate were decreased significantly after Sin Bee Tang water extract, 0.1ml/kg, administration. 2. Glomerular filtration rate, renal plasma flow and urinary excretion of electrolytes were increased significantly after Sin Bee Tang water extract, 0.25ml/kg, administration. 3. Plasma cortisol concentration increased significantly after Sin Bee Tang water extract, 0.25ml/kg, administration. These results suggest that the therapeutic action of Sin Bee Tang for 'Su Chun (水喘)' has a relation with the increase of plasma cortisol and renal hemodynamic effect.

• Membrane and Water Treatment
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• 제6권6호
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• pp.477-488
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• 2015

This study demonstrates that low pressure membranes are the ideal choice for industrial and/or municipal wastewater treatment by showing some promising experimental results, understanding different membrane filtration models, studying the potential of membrane bioreactors (MBRs), considering ceramic membranes fabrication and illustrating the role of nanotechnology in membranes. Cost study calculations are included to determine the treatment cost as well as the initial cost of various membrane types. Results showed that integrated membranes are preferred over MBR in case of average capacities. However, higher capacity situations are the most economical choice for MBR. It is shown that the least treatment cost in MBR was about $0.13/m^3$. However, the $0.13/m^3$ is the theoretical cost which is very small compared to the actual average MBR treatment cost of $0.5/m^3$.

• Composites Research
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• 제35권3호
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• pp.216-221
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• 2022

Recently, the worldwide demand for disposable masks has increased due to COVID-19 infections and severe air pollution. Personal masks should reduce breathe resistance while maintaining filtering performance. In this study, a solution blowing process is used to produce composite nanofiber filters to co-spin two polymers at once. The manufacture process of the various fiber diameter filter was designed, and the filtration performance and differential pressure of the prepared filter was investigated. Poly vinylidene fluoride-hexafluoropropylene (PVDF-HFP) and Polylactic acid (PLA) fibers were chosen to be entangled together in a layer with a diameter of 1.05 ㎛ and 0.33 ㎛. Composite nanofilters showed up to 87% filtration efficiency and 32 Pa differential pressure.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2001년도 추계 학술발표회 논문집
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• pp.273-278
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• 2001

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2009년도 추계학술대회 논문집
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• pp.594-595
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• 2009

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 춘계총회 및 연구발표회 초록집
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• pp.44.2-44.2
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• 2004