• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1225-1232
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• 2000

This study was carried out to define the effect of electron beam irradiation on the physico-chemical characteristics of sewage sludges. The experimental evidence showed that both pH and alkalinity of irradiated sludge were generally increased as the dose of irradiation increased. It was found that the soluble protein concentration (SPC) and soluble chemical oxygen demand (SCOD) from the sludge right after electron beam irradiation at 3kGy(kilo-joule/kg) increased 2.2 times and 10 times respectively more than those sludges without electron beam treatment. This highly solubilized organics could be resulted in a good soluble substrate for the subsequent anaerobic digestion process. The specific resistance of filtration (SRF) tests showed that sludge dewaterability under electron beam irradiation at 6kGy was found to be 8.8 times higher than that of unirradiated sludge. The sludge dewaterability seemed to be directly related to the dosage of electron beam irradiation up to 10kGy. However, the efficiency of sludge dewaterability tended to be smaller with higher applied irradiation dose. In comparing treatments by different inorganic chemical conditioner with irradiated and unirradiated sludges, it appeared that the dewaterability with irradiated sludge was approximately 4-10 times better that that of unirradiated sludge. Even electron beam treatment itself could replace the result from the sludge conditioned with inorganic chemical coagulants.

• Membrane Journal
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• v.15 no.2
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• pp.147-156
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• 2005

It is well-known that polyethersulfone (PES) has high $CO_2$ selectivity over $N_2\;(or\;CH_4)$ and excellent pressure resistance of $CO_2$ plasticization among muy commercialized engineering plastics[1-4]. Asymmetric PES hollow fiber membranes for flue gas separation were developed by dry-wet spinning technique. The dope solution consists of PES, NMP and acetone. Water and water/NMP mixtures are used in outer and inner coagulants, respectively. Gas permeation rate (i.e., permeance) and $CO_2/N_2$ selectivity were measured with pure gas, respectively and the micro-structure of hollow fiber membranes was characterized by scanning electron microscopy. The effects of polymer concentration, ratio of NMP to acetone, length of air gap, evaporation condition and silicone coating were investigated on the $CO_2/N_2$ separation properties of the hollow fibers. Optimized PES hollow fiber membranes exhibited high permeance of $25\~50$ GPU and $CO_2/N_2$ selectivity of $30\~40$ at room temperature and have the apparent skin layer thickness of about $0.1\;{\mu}m$. The developed PES hollow fiber membranes, would be a good candidate suitable for the flue gas separation process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1307-1311
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• 2008

This study was conducted to evaluate the quality characteristics of mugwort-tofu prepared by purified salt (A1), sun-dried salt (A2), bamboo salt (A3), and deep ground water salt (A4) in addition to $CaCl_2$ as coagulants. Addition of various salts with $CaCl_2$ increased yield of the tofu resulting in high content of lipid, protein and mineral contents of mugwort-tofu. Sun-dried salt was most effective in yield of the tofu among tested salts. It was also most efficient in increasing protein, and lipid contents of the tofu. The amounts of Ca, K, Mg, and Na were highest in mugwort-tofu prepared with sun-dried salt, while they were lowest in the tofu with deep ground water salt. The texture analysis showed the tofu prepared with various salts generally increased the hardness and gumminess of the tofu significantly. The sensory evaluation of the tofu with various salts demonstrated that the saltiness, tastiness, chewiness, and overall acceptance were enhanced significantly. Among tested salts, bamboo salt showed the highest overall acceptance in mugwort-tofu, followed by deep ground water salt, purified salt, and sun-dried salt.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.547-554
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• 2006

The overall objective of this research was to find out the role of rapid mixing conditions in the species of hydrolyzed Al(III) formed by Al(III) coagulants and to evaluate the distribution of hydrolyzed Al(III) species by coagulant dose and coagulation pH. When an Al(III) salt was added to water, monomeric Al(III), polymeric Al(III), precipitate Al(III) was formed by Al(III) hydrolysis. The method of hydrolyzed Al(III) species characterization analysis was based on timed spectrophotometer with ferron as a color developing reagent. The hydrolytic species were divided into monomer, polymer, precipitate from the reaction kinetics. And then, the color intensity for monomeric Al(III) was read 3 min after mixing. With standard Al solution containing monomeric Al(III) only, the Al-ferron color intensity slightly increased with until about 3 min. During the rapid mixing period, for purewater, formation of dissolved Al(III) (monomer and polymer) was similar to rapid mixing condition, but for raw water, the species of Al(III) hydrolysis showed different result. During the rapid mixing period, for high coagulant dose, Al-ferron reaction increases rapidly. The kinetic constants, Ka and Kb, derived from Al-ferron reaction. The kinetic constants followed very well the defined tendencies for coagulation condition. For pure water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values. Also, for raw water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.523-528
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• 2007

The objectives of this research are to investigate the mechanism of coagulation affecting UF, find out the effect of metal salt coagulant on membrane fouling. Either rapid mixing + UF or slow mixing + UF process caused much less flux decline. For PACl coagulant, the rate of flux decline was reduced for both hydrophilic and hydrophobic membrane than alum due to higher formation of flocs. In addition, the rate of flux decline for the hydrophobic membrane was significantly greater than for the hydrophilic membrane, regardless of pretreatment conditions. In general, Coagulation pretreatment significantly reduced the fouling of the hydrophilic membrane, but did little decrease the flux reduction of the hydrophobic membrane. When an Al(III) salt is added to water, monomers, polymers, or solid precipitates may form. Different Al(III) coagulants (alum and PACl) show to have different Al species distribution over a rapid mixing condition. During the rapid mixing period, for alum, formation of dissolved Al(III) (monomer and polymer) increases, but for PACl, precipitates of $Al(OH)_{3(s)}$ increases rapidly. This experimental results pointed out that precipitates of $Al(OH)_{3(s)}$ rather than dissolved Al(III) formation is major factor affecting flux decline for the membrane.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.825-831
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• 2006

This study investigated the utilization of apricot as a coagulants for tofu manufacture, and compared the quality characteristics and shelf-life of tofu made by A2(2% apricot juice), A4(4% apricot juice), A6(6% apricot juice), A8(8% apricot juice) in comparison with those of C(G.DL). A2 tofu(323.00 g) showed the highest yield of tofu and the tofu yield decreased with increasing apricot juice content. In color, the lightness of tofu was decreased with increasing apricot juice content, while redness and yellowness were increased. The hardness of tofu coagulated with apricot juice was higher than that of the coagulated C(G.DL) and the springiness of A6 and A8 was higher than that of C(G.DL) while that of the other tofus was lower than C(G.DL). The brittleness of tofu was increased with increasing apricot juice content. The pH value of tofu coagulated with apricot juice was increased during storage at $0^{\circ}C$ and the acidity was decreased. Two percent apricot juice tofu had good overall preference.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.318-323
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• 1995

To improve wastewater treatment in a confectionery factory and to optimize chemical coagulation process, this study was performed. $COD_{Mn}$ and total solid of untreated wastewater were $200{\sim}820ppm\;and\;860{\sim}1350ppm$, respectively. Composition of total solid was sugar 40%, protein 10%, hexane-soluble 20%, and ash 30%. Turbidity at 650 nm and the amount of suspended solid (SS) showed correlation, thus turbidity could be used for the on-line measurement of SS. The most effective combination of coagulants for the removal of $COD_{Mn}$ and SS was that of $Al_2(SO_4)_3\;and\;Ca(OH)_2$. The optimal concentration of $Al_2(SO_4)_3\;and\;Ca(OH)_2$ was 480 ppm and 200 ppm, respectively. Optimal retention time of wastewater for $Al_2(SO_4)_3$ addition $Ca(OH)_2$ addition : flocculation was 2 : 2 : 10 min. Multiple treatment of $Al_2(SO_4)_3:Ca(OH)_2$ overcame coagulation inhibition by gelatin and detergent, and addition of microbial sludge reduced it.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.3
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• pp.23-32
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• 2014

Recently, it is increase in the processing of organic waste using anaerobic digestion. Therefore, the studies on the processing method for increasing the anaerobic digestion waste water. But it is very difficult to solid-liquid separation, because the characteristics of anaerobic digestion waste water. So this study evaluate solid-liquid separation efficiency of anaerobic digestion sludge using CST(Capillary Suction Time), TTF(Time to Filter). To address this problem, a membrane filter press of the lab scale was produced and the anaerobic digestion wastewater was applied to it. Polymer coagulants were found to be most suitable 7192PLUS and 1T60, It is necessary to minimum injection concentration is 7192PLUS (200 mg/L), 1T60 (100 mg/L). To evaluate dehydration efficiency, it was measured the moisture content of the dehydrated cake and suspended solids of decanted water. As a result, showed that a high removal efficiency of 97.4% when the solid-liquid separation using the membrane filter press. And the moisture content of the dehydrated cake was less than 65%.

• Membrane Journal
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• v.15 no.4
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• pp.272-280
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• 2005

In this study, asymmetric polysulfone membranes were prepared by the phase inversion method and the casting solutions were containing N-methyl-2-pyrrolidone (NMP) as a solvent. Deionized water and various alcohols(methanol, ethanol, and propanol) were used as a coagulation medium in preparing asymmetric polysulfone membranes. This study investigates the effect of alcohol coagulants having different solubility parameters as a pore-former on the construction of porous structures and their pure water permeation properties. Asymmetric polysulfone membranes immersed in the pure alcohol coagulation bath solution showed the typical sponge-like structures and the reduced water permeability as compared with those of polysulfone membranes precipitated in the pure water coagulation bath solution. In the water/alcohol mixtures, asymmetric polysulfone membranes showed the finger-like structures with the sponge-like structures. Therefore, the sponge-like structure of polysulfone membrane was formed under the delayed demixing systems while the porosity of membrane was decreased significantly. The water permeability of polysulfone membrane precipitated in the pure water coagulant showed 164 [$L/m^2hr$] at 14.7 psi. In case of polysulfone membranes prepared in the pure methanol and ethanol coagulant, they showed the water permeability of 56 and 30 [$L/m^2hr$], respectively.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1083-1091
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• 2000

The objective of this study is to develop effective and economical treatment processes for the removal of non-biodegradable organics by reusing the sludge generated from Fenton's Oxidation Process. It was found that about 50% of coagulants and 50% of catalyst can be reduced by reusing the sludge generated from Fenton's Oxidation Process. It was also found that the amount of sludge generation can be reduced in coagulation process and Fenton's Oxidation Process. From the results of bench-scale test, it was found that the average removal efficiency increased to 8.5% and the amount of sludge generation was reduced up to 35% by reusing the sludge as coagulant. The average organic removal efficiency increased to 5.3% and the amount of sludge generation was reduced up to 14% by reusing the sludge as catalyst in Fenton's Oxidation. It can be concluded that the reuse of sludge generated from Fenton's Oxidation Process would be reduced cost of chemical consumption and Fenton's sludge treatment.