• Membrane Journal
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• v.19 no.2
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• pp.165-171
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• 2009

This study was for the evaluation of adaptability of the fiber filter as the pre-treatment of the RO membrane through SDI (Silt Density Index) measurement. The turbidity of raw waters were $0.76{\sim}1.6$ NTU for the effluent of sewer treatment plants (STP) and $2.2{\sim}3.3$ NTU for sea waters and 100 NTU for the surface water. The turbidity of the $2^{nd}$ filtrate of the serially connected two fiber filters was $0.07{\sim}0.25$ NTU and $SDI_{15}$ was $1.4{\sim}2.8$ when the 17% PAC was dosed $10{\sim}30ppm$. Results of the turbidity and $SDI_{15}$ of the $2^{nd}$ filtrate of the fiber filter which were compared with them of the lab scale MF/UF disc filter for the same STP's effluents showed that filtrate quality were enhanced with a little on the order of two stage fiber filter>MF>UF, the difference in $SDI_{15}$ was only $0.7{\sim}1.0$. So, the filtrate of the serially connected two stage fiber filter could satisfy $SDI_{15}$ 5.0 safely which was normally required for the feed water by the RO membrane supplier and it means the serially connected two stage fiber filter could be applied as the pre-treatment process of the RO membrane.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.13-21
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• 2008

With the rise in membrane applications, residuals management has become a growing challenge for membrane system. The primary residuals of MF/UF (microfiltration/ultrafiltration) system results from the wastes generated during backwashing. Many regulatory agencies, utilities, and water process engineers are unfamiliar with the characteristics and methods for treatment and disposal of membrane residuals. Therefore, this study was performed to investigate the backwash residuals water quality from the pressurized system with and without pre-coagulation, and to suggest approaches for the backwash residuals treatment. Pressurized MF system was installed at Guui water intake pumping station and operated with raw water taken from the Han River. We compared performances with and without the recycling backwash residuals at flux conditions, 50 LMH and 90 LMH with and without pre-treatment (coagulation). Based on the results, recycling of backwash residuals in pressurized system with pre-coagulation showed applicability of backwash residuals managements. Moreover, the recovery rate also increased up to over 99%.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.541-547
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• 2013

It is important to establish water treatment technologies for drinking water because Korea belongs to water-stressed country. Leachate from recent incident of foot-and-mouth disease has become an opportunity to be aware of the need to manage water quality. Water purifiers are adopted to four or five steps of filtration process. Each steps are composed of a sediment filter, a pre-carbon filter, an UF or a RO membrane filter and a post-carbon filter. And additionally a ceramic filter can be used as a final stage. In this study, operational conditions in each steps are examined and characteristics of each filters are investigated. SEM analysis is used for filter surface and shape investigation using 6 commercial samples. Pore sizes of the sediment filter, the UF membrane filter, and the RO membrane filter are 30~47 ${\mu}m$, 0.005~0.5 ${\mu}m$, and 0.025~0.25 ${\mu}m$, respectively. Specific surface areas of activated carbons are ranged from 622 to 1,308 $m^2/g$.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.753-761
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• 2005

In this study, pretreatment of organic matters with $MIEX^{(R)}$ was evaluated using bench-scale experimental procedures on four organic matters to determine its effect on subsequent UF membrane filtration. For comparison, coagulation process was also used as a pretreatment of UF membrane filtration. Moreover, the membrane fouling potential was identified using different fractions and molecular weights of organic matters. From the removal property of MW organic matters by coagulation process for the sample water NOM and AOM, the removal efficiency of high MW organic matters were much higher than those of low MW organic matters. It was shown that the removal efficiency of high MW organic matter more than 10 kDa was lower than that of low MW organic matter for $MIEX^{(R)}$ process. For the change of permeate flux by the pretreatment process, $MIEX^{(R)}$+UF process showed high removal efficiency of organic matter as compared with coagulation-UF processes, but high reduction rate of permeate flux was presented through the reduction of removal efficiency of high MW organic matter. From sequential filtration test results in order to examine the effect of MW of organic matter on membrane fouling, it was found that the membrane foulant was occurred by high MW organic matter, and the DOC of organic matter less than 0.5 mg/L was working as the membrane foulant. In the case of sample water composed of low MW organic matter less than 10 kDa, since the low MW organic matter less than 10 kDa has high removal efficiency by $MIEX^{(R)}$, low reduction rate of permeate flux is obtained as compared with coagulation-UF processes. In summary, it is required to conduct the research on physical/chemical characteristic of original water before pretreatment process of membrane process is selected, and a pertinent pre-treatment process should be employed based on the physical/chemical characteristic of original water.

• Membrane and Water Treatment
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• v.8 no.1
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• pp.1-18
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• 2017

In this study, reuse of biologically treated wastewater of denim washing and dyeing industry has been evaluated by membrane technologies. After that experiments were carried out at laboratory scale in textile dyeing unit by using obtained permeate water samples on 100% cotton based raw fabric belonging to examined industry. During membrane experiments, two different UF (UC100 and UC030) and two different NF (NP010 and NP030) were evaluated under alternative membrane pressures. In permeate water obtained on selected samples, conductivity at the range of $1860-2205{\mu}S/cm$, hardness at the range of 60 to 80 mg/L, total color at the range of 2.4 to 7.6 m-1 and COD at the range of 25-32 mg/L was determined. The following analyzes were performed for the dyed fabrics: perspiration fastness, rub fastness, wash fastness, color fastness to water, color fastness to artificial light, color measurement through the fabric. According to analysis results, selected permeate water have no negative impact on dyeing quality. The study showed that membrane filtration gave good performance for biologically treated textile wastewater, and NF treatment with UF pre-treatment was suitable option for reuse of the effluents.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.155-165
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• 2018

The objective of the research was to evaluate the effect of particle pre-treatment on physical, mechanical, and durability of jatropha fruit hulls (JFH) particleboard. The pre-treatments included were immersing in cold water, hot water, and acetic acid solution. After each treatment, the particles were dried up to 3% moisture content. Urea-formaldehyde (UF) resin was used to fabricate particleboards with board size, thickness and density target of 25 cm by 25 cm, 0.80 cm, and $0.70g/cm^3$, respectively. Board pressed at $130^{\circ}C$ for 10 minutes, and $25kg/cm^2$ pressure. The evaluation of particleboard followed the JIS A 5908-2003. Whilist their resistance to subterranean termite test (mass loss, mortality, antifeedant value and feeding rate) refers to the Indonesian standard (SNI 01.7207-2006). The physical and mechanical properties of particleboards showed that all pre-treatments decreased the pH of particles. Overall, all particle immersing treatments resulted of better physical and mechanical properties of particleboard than those of untreated ones. The acetic acid treatment resulted the best physical and mechanical properties of particleboard. Based on the mass loss of JFH particleboard, hot water and acetic acid treated particleboards were classified into weak resistance to subterranean attack. The other two treatments were classified into very weak resistance. Hot water treated particleboard provided the highest mortality and antifeedant as much as 87.40% and 34.20%, respectively. Based on antifeedant classification, hot water treated particleboards were classified into moderately strong resistance, while other treatments were categorized into weak resistance. The lowest feeding rate value ($45.30{\mu}g/termite/day$) was attained by hot water treatment.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.33-41
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• 2013

This study was performed to analyse cause of quality deterioration using byproduct of plywood and to determine physical and mechanical properties of particleboard used new bonding condition we found. The result of bending strength of Com-Ply board using EMDI is 57.7 $N/mm^2$ on linear direction and 25.1 $N/mm^2$ on vertical direction. EMDI has better water-resisting qualities than Urea formaldehyde adhesive according to result of thickness swelling and water absorption test. Pre-treatment soaked particle 72 hours in water caused increase of HCHO emission.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.548-557
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• 2015

This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.2
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• pp.131-137
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• 2016

The development of alternative water resources has emerged as an effective method for solving drought of water resources due to extreme weather and increase in water consumption. Recently, in Korea, there has been active research on reverse osmosis desalination technology, wastewater reuse using forward osmosis membranes, and the forward osmosis(FO)-reverse osmosis(RO) hybrid process combining these two technologies. In this study, the basic performance of FO membranes manufactured by three domestic and international manufactures such as Microfilter Co., Ltd., Toray Chemical Korea Inc., and Hydration Technologies Inc., were investigated for wastewater reuse. In addition, as an experiment to select feed solution, the selected membranes were operated 48 consecutive hours using three secondary effluents pretreated by the UF membrane with a pore size of $0.1{\mu}m$ and auto strainer with pore sizes of $1{\mu}m$ and $100{\mu}m$ as feed solution. Although there was not much difference in the operating performance. Thus, the treated water using the $100{\mu}m$ auto strainer was selected as feed solution applied to the assessment.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.436-442
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• 2008

Hydroxyproline and Pro-Hyp dipeptide are the digestive products of collagen hydrolysate called collagen peptide. Some suggested that collagen peptides could improve aged or damaged skins, however, the effects of collagen peptides on the skin have not been known. In this study, we investigated the effects of digestive products of collagen peptides, hydroxyproline and Pro-Hyp dipeptide on skin quality using the UV-damaged dorsal skin of hairless mouse as a model system. Female SKH hairless mice were pre-irradiated with UV for 7 weeks, and then hydroxyproline, Pro-Hyp dipeptide were orally administered for 7 weeks with UV irradiation. Wrinkle formation (by replica image), skin elasticity, barrier status (by TEWL, transepidermal water loss), epidermis thickness, and biophysical changes in the stratum comeum (by hematoxylin & eosin staining) were examined. With the oral peptide treatment, effects such as skin barrier maintenance, anti-skin thickening, and recovery of the stratum corneum were observed. These results indicate that oral intake of collagen peptides may have beneficial effects on damaged skin cells.