• Proceedings of the Membrane Society of Korea Conference
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• 1997.04a
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• pp.87-109
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• 1997

Reverse osmosis(R/O), ultrafiltration(UF) and microfiltration (MF) processes are widely used for water treatment. In the seminar, characteristics of typical membrane modules including tubular, hollow fiber, plate and frame and spiral wound types will be discussed in detail. The design methods based on hydrodynamics for hollow fiber and spiral wound modules will be introduced analytically. Concentration polarization (CP) and membrane fouling mechnism as well as the techniques for CP reduction will be handled. The CP control techniques contain chemically modified membrane surface, pretreatment of feed water, operation of low trans-membrane pressure, chemical or physical cleaning methods and artificial production of various fluid turbulences near the membrane surface, etc. In especially, the recent commercial membrane modules for CP control including module rotation, vibration and Taylor or Dean vortex system will be introduced and discussed in detail.

• Korean Membrane Journal
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• v.10 no.1
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• pp.39-45
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• 2008

Polyelectrolyte complex based on two anionic polysaccharides, composed of sodium alginate and carrageenan, were prepared by interacting with divalent calcium ions in solution. The effects of annealing on the structural deformation of polyelectrolyte complex and on their characteristics at removing water from a methanol mixture from the point of molecular sieve were investigated and discussed. The result showed that the structural deformation of the annealed polyelectrolyte complex has an effect on the free volume between these polymer chains and the chelate segments such a shrinking of the overall morphology, which act as a molecular sieve in the separation of methanol and water mixtures.

• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.4
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• pp.4265-4273
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• 1976

1. Fine aggregates of concrete are very important for the construction works and construction cost determination. Most of fine aggregates are from the river sand, but the amount of storage in the river side is steadily decreasing due to continuous construction works. Therefore, another source of fine aggregates is needed to meet increasied demand of sand. 2. Beach sand is a possible source of fine aggregates. But rust of steel bar is caused by CL-chemical of beach sand. Therefore, desalinization of beach sand is requested to get durable reinforced concrete. Economical methods of desalinization are as follows. (a) Flooding and drainage method. (b) Washing of beach sand with water supply and mixing. (c) Spreading of beach sand on the land and leaching by rain water for a few month. 3. Hardening of concrete with beach sand is accelerated due to salt, Thus early stage strength increase leads to make cracks. Also later stage strength decreases and durability becomes worse. By using appropriate admixture, the quality of concrete can be improved.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.529-536
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• 2002

The purpose of this paper os to present and discuss some of flow and drain observed in modelling results. Because dredged fill ground of Yul-Chon located in the south coast of Korea is very soft, this ground should be improved after operation of surface stabilization. There are surface stabilization method such as chemical stabilization, desiccation, horizontally vacuum drain, replacement, and geosynthetics. In Yul-Chon, PTM(Progressive Trenching Method) is adopted to provide the necessity condition of surface desiccation. In the case trench in the dredged soft ground is formed by PTM equipment, pore water in the ground is drained through trench. There, drain and desiccation of surface ground increase, and bearing capacity is improved. In this research, when trench in the dredged soft ground is formed by PTM equipment, permeable characteristics and drain efficiency of pore-water are analyzed using SEEP/W software package. Results show variation of total head, pressure head, flux, hydraulic gradient, and flow quantity.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.277-283
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• 2011

The goal of this study was to make more efficient use of Ligularia fischeri which has both medical and cooking applications after freezing and drying. We manufactured Sulgidduk containing 0, 2, 4, 6 and 8% of Ligularia fischeri powder. Chemical analysis showed that Ligularia fischeri powder contained, 5.77% water, 19.97% crude protein, 1.89% crude fat, 13.12% crude ash, and 9.73% crude fiber. The water content of Sulgidduk to which Ligularia fischeri was added ranged from 37.72~40.20%. As more Ligularia fischeri was added, the L value and 'a' value increased, while the 'b' value did not significantly change. Optimal preference was for a 4% content of added Ligularia fischeri powder. Based on the results of this experiment, Sulgidduk manufactured with added Ligularia fischeri powder showed less hardness than the control group throughout a period of storage, and adequate addition of Ligularia fischeri powder can effectively enhance the storability of Sulgidduk containing Ligularia fischeri.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.945-954
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• 2023

In this study, Sparassis crispa(cauliflower mushroom), which is rich in beta-glucan, was pulverized using ultrafine grinding technology for its potential utilization as a diverse food ingredient. The physical and antioxidant properties of cauliflower mushroom powder were evaluated at various grinding times. The results showed that as the grinding time of cauliflower mushroom increased, the average particle size significantly decreased (p<0.05). Additionally, the water-holding capacity, swelling capacity, and water solubility index of cauliflower mushroom increased significantly(p<0.05). Based on the analysis mentioned above, cauliflower mushroom prepared as a superfine powder for 5 minutes exhibited superior physical and chemical properties as well as antioxidant characteristics and is expected to be widely used in various foods.

• Journal of the Korean Electrochemical Society
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• v.15 no.1
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• pp.41-47
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• 2012

An annular flow type of copper electrolysis reactor was setup in order to generate the copper ions to remove algae in water. The operating characteristics of the reactor and the effect of copper ion on algae have been considered. By controling the applied current, the copper ion concentration could be obtained as desired level and the faradaic efficiency was above 90%. When the flow rate was increased, the copper ion concentration was linearly decreased due to the dilution effect and the effect of concentration overpotential was insignificant. With the increase of pH in water, the copper ion concentration was linearly decreased and not affected by the conductivity of the water. The concentration of chlorophyll-a was sharply decreased with the increase of copper ion concentration. The algae was effectively removed as the copper ion concentration was above 0.2 ppm. There was no difference between the copper ions obtained by dissolving copper sulfate and those produced by copper electrolysis. The algae removal efficiency was above 90% after 5 days as the copper ion concentration was above 0.4 ppm.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.93-107
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• 1998

Because of its stable quantity and quality, groundwater has long been a reliable source of drinking water for domestic users. Rapid economic growth and rising standards of living have in recent years put severe demands on drinking water supplies in Korea. Groundwaters that are currently being used for natural mineral water were hydrochemically evaluated and investigated in order to maintain their quality to satisfy strict health standards. There exist 15 natural mineral water plants in the Okcheon metamorphic belt. Characteristics of groundwaters are different from those of other areas in that electrical conductivity, hardness, contents of Ca, Mg and $HCO_3$are relatively high. The content of major cations is in the order of Ca>Mg, Na>K, whereas that of major anions shows the order of $HCO_3$>$SO_4$>Cl>F. The fact that the Ca-Mg-HCO$_3$type is mostly predominant among water types reflects that dissolution of carbonates that are abundantly present in the metamorphic rocks plays an important part in groundwater chemistry. Representative correlation coefficients between chemical species show Mg-$HCO_3$(0.92), Ca-$HCO_3$(0.88), Ca-Mg(0.80), Ca-Cl(0.78), Mg-$SO_4$(0.78), Ca-$SO_4$(0.71), possibly due to the effect by dissolution of carbonates, gypsum or anhydrite. Determinative coefficients between some chemical species represent a good relationship, especially for EC-(K+Na+Ca), Ca-$HCO_3$, Ca-Mg, indiacting that they are similar in chemical behaviors. According to saturation index, most chemical species are undersaturated with respect to major minerals, except for some silica phases. Groundwater is slightly undersaturated with respect to calcite and dolomite, whereas it is still greatly undersaturated with respect to gypsum, anhydrite and fluorite, Based on the Phase equilibrium in the systems $NA_2$O-$Al_2$$O_3$-$SiO_2$-$H_2$O and $K_2$O-$Al_2$$O_3$-$SiO_2$-$H_2$O, it is clear that groundwater is in equilibrium with kaolinite, evolved from the stability area of gibbsite during water-rock interaction. It is expected that chemical evolution of groundwater continue to proceed with increasing pH by reaction of feldspars, with calcite much less reactive.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.725-734
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• 2012

The outbreak of foot and mouth disease in November 2010 raised many social, economic and environmental issues and water contaminations by leachate from carcass disposal sites particularly emerged as a serious concern. In oder to efficiently handle these problems, a critical method is required to transport leachate to livestock manure and sewage treatment plants and purify it. This study aims to present the best applicable method to transport leachate from carcass disposal sites into livestock manure and sewage treatment facilities. We investigated the biological and chemical characteristics such as BOD, COD, SS, TN, TP and Total coliforms. Current conjugated treatments in livestock manure and sewage treatment plants was studied by surveying the operations of those facilities. The NIER-MASS(National Institute of Environmental Research - Mass Balance Evaluation System of Sewage Treatment Facilities) program was applied to present the best conjugated treatment method through estimating the maximum daily load to meet the water quality standards in effluent.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.453-462
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• 2010

Nowadays, the challenges of ensuring good water quality and quantity of river are becoming more important for human society, but there has been troublesome for purifying river water. In this study, we performed the fundamental study of a river water treatment system using riverside soil and eco-friendly optimal media for improving river water quality and can also treat a large amount of river water. As the results of the physical and chemical characterization of the two different soils (Kyungan and Chungrang, The Republic of Korea), which were collected from real stream sides in the Han River basin, and five kinds of media (zeolite, perlite, steel slag, woodchip and mulch), both soils were all classified as a sand, and effective size ($D_{10}$) and uniformity coefficient (U) of the soil were about 0.2 mm and 4 or so, respectively. Through the batch and column experiments with the soil and eco-friendly media, zeolite and mulch were found to be efficient for decreasing nitrogen. In addition, steel slag was especially superior to the other media for phosphorus removal. From soil reforming tests volume ratios were 2.8, 1, and 1 of Kyungan soil, zeolite, and steel slag hydraulic conductivity of mixed soil was increased $1.30{\times}10^{-2}$ from $2.85{\times}10^{-3}$ of Kyungan soil, and the removal efficiencies of nitrogen and phosphorus were also improved. These results show that reforming of the soil enhanced the purification of a large amount of water, and zeolite, mulch, and steel slag might be facilitated as proper functional media.