• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.415-420
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• 2001

Water usage in the semiconductor industries is dramatically increased by not only using bigger wafer from 8 inches to 12 inches but also by adapting new process such as Chemical Mechanical Planarization (CMP) process invented by IBM in late '80. However, The document published by International Semiconductor Association suggests the decreasing ultra pure water (UPW) use from 22 gallon/in$^2$in 1997 to 5 gallon/in$^2$ in 2012. The criteria will possibly used as exporting obstacle in the future. Generally, Solid content of CMP slurry is about 15wt%. The slurry is diluted with UPW before fed to a CMP process. When the slurry is discharged from the process as waste, it contains 0.1~0.6wt% of solid content and 9~10 at pH. The CMP waste slurry is discharged to stream with minimum treatment. In this study, to find optimum condition of coagulation for water recovery from the waste CMP slurry various condition of coagulation were examined. After coagulation far 0.1 wt% solid content of waste CMP slurry, the sludge volume was 10~15% after 30 min of sedimentation time. For the 0.5 wt%, sludge volume was 50~55% after one hour of sedimentation time. For more than 80% of water recycling, the solid content should be in the range of 0.1 to 0.2wr%. Based on the result of the turbidity removal, the Zeta Potential and the analysis of heavy metals, the optimum condition for 0.1 wr% of waste CMP slurry was with 20 mg/L of PACI at 4 to 5 of pH. The result showed that the optimum conditions fer the 0.1 wt% waste CMP slurry were 100mg/L of Alum at 4~5 of pH, 100 mg/L of MgCI$_2$at pH 10 to 11 and 100 mg/L of Ca(OH)$_2$at pH 9 to 11, respectively.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.715-718
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• 2001

This study uses traditional alum coagulation and sedimentation process to treat CMP wastewater from cleaning after polishing. The primary goal is to successfully recycle both solid fines and water for semiconductor manufacturing. Results indicated that CMP wastewater may be successfully treated to recover clean water and fine particles by alum coagulation. The optimum operating conditions for coagulation are as fellowing: alum dosage of 10 ppm, pH at 5, rapid mixing speed at 800 rpm, 5 min rapid mixing time, and long slow mixing time. The treated water with low turbidity and an average residual aluminum ion concentration of 0.23 ppm may be considered for reuse. The settled sludge after alum coagulation contains mainly SiO$_2$particle with a minor content of aluminum (1.7 wt%) may be considered as raw materials for glass and ceramic industry.

• Journal of the Korean Applied Science and Technology
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• v.3 no.1
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• pp.15-22
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• 1986

The purpose of this study was to investigate the effects of garlic diet on blood coagulation in cholesterol-fed rats. 36 male rats were divided into six groups and fed experimental diet for three weeks. Two-levels (2% and 4%) of fresh and boiled garlic were supplemented to the stock diet with 2% cholesterol and 0.25% bile salt for the experimental diet. After the rats fed with experimental diets during 3 weeks, the whole blood coagulation time, the content of plasma fibrinogen, the fibrinolytic activity and the prothrombin time were measured. The results are summarized as follows; 1. Garlic diet have no influence on body weight and food consumption in rats. 2. In the case of cholesterol-fed group, the whole blood coagulation time was decreased 24.3% compared with the normal group(A). But garlic diet group(C) was similar to the normal group(A) and groupD-F was increased 4.9-11.5%. 3. The content of plasma fibrinogen of cholesterol-fed group was higher 114.5% than that of normal gropu(A). In the garlic diets(C-F) the contents of plasma fibrinogen were increased 33.1-63.8%. 4. The fibrinolytic activity of cholesterol diet was decreased 16.2% compared with the normal group(A) but was increased 10.9-44.5% compared to the garlic diets(C-F). 5. The prothrombin time of cholesterol-fed group was decreased 8.9% compared with normal group(A) but was increased 8.0-46.3% in garlic diets(C-F). As mentioned above, the garlic diets increased whole blood coagulation time, prothrombin time and fibrinolytic activity and decreased the content of fibrinogen. For that reason it is thought that the garlic diets have a anticoagulation effect regulating the fibrinogen synthesis in liver.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.99-105
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• 1998

This research explored the feasibility of preparing and utilizing a preformed polymeric solution of Al(III) for coagulation in water treatment. Slow base(NaOH) injection into supersaturated aluminum chloride solutions did produce high yields of the type of Al polymers useful to water treatment applications. PACl's characteristic analysis showed that the quantity of polymeric Al produced at value of $r(OH_{added}/Al)=2.2$ was 83% of the total aluminum in solution, as showing maximum contents and precipitate was dramatically increased when r was increased above 2.35. And PACl was stable during sitoring period so aging effect was negligible. Results of the coagulation of Nakdong river waters with three PACls showed that the effectiveness of the three coagulants can be considered as r = 2.2 > r = 2.0 > r = 2.35 which are also the order of higher polymeric aluminum contents. Coagulation results for synthetic water exhibited optimum dose of 0.25mM Al, for three PACls, but above optimum dose, r = 2.0 and 2.2 PACl impaired the coagulation and sedimentation of turbidity and humic acid because of the restabilization of particulate. The effect of pH for on coagulation of Nak Dong River water showed that it had much effect turbidity and TOC removal, especially near pH 7. But pH effect was little for turbidity and TOC removal when r = 2.35 PACl was used for coagulation, that PACl had much more precipitates content.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.363-369
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• 1999

This study aimed to elucidate the relationship between theoretical parameters affecting the coagulation process and the real coagulation phenomenon applied to the dye wastewater. Emphasis was placed on the effective removal of the suspend particulates. Parameters studied in this study are pH, coagulant concentration and surface potential. Optimal dosages of coagulants by the measurement of the zeta potential at lower then $25^{\circ}C$ are 5\times$10^P-3}$ M of $FeCl_3 and 1.4\times10^{-6}M of Fe_2(SO_4)_3$. The results were well agreeded with the separate Jar-test results. Emphasis was also placed on the relationship between water quality and the content of SS. It was found that the COD and DOC were reduced to 65% and 85%, respectively. The turbidity at the above condition was reduced from 300 NTU to 0~1 NTU. Efforts were made to clarify the behavior of the suspend solid as affecting the water quality. 12,000~13,000 particles/10mL in $1~50\mu$m size range particulates in the raw wastewater were reduced to 300 particle/10mL in the same range after treatment. This research has proposed the methodology to find out the optimal condition of coagulation for small scale wastewater treatment plant or chemical coagulation process.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.66-72
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• 2015

The aim of this study was to enhance of the Discfilter process (maximum treatment capacity - 500 ton/day) removal efficiency for small-scale wastewater reclamation under various influent wastewater conditions (with / without coagulation process, coagulant content and temperature). The result of chemical resistance test for fiber filter in the Discfilter that weight loss was obtained with 0.535% under pH 3, 0.092% under pH 9 and 0.028% under 10% NaClO. The removal efficiency test of Discfilter process on the with / without coagulation process showed that with coagulation process condition was occurred COD_Mn of 42.26 ± 0.61, BOD₅ of 88.72 ± 0.44, T-P of 84.67 ± 0.72 and SS of 90.58 ± 0.61. The removal efficiency of Discfilter process on the coagulant content (4.5, 5.0 and 5.0 mL/min) and temperature (< 10℃, 10℃~ 20℃ and > 20℃) conditions were increased as coagulant content and temperature increased. This study demonstrated the potential application of Discfilter process for small-scale wastewater reclamation.

• Journal of environmental and Sanitary engineering
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• v.16 no.3
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• pp.80-86
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• 2001

This research was carried out to investigate the effect of microscopic silica matrix coagulation on heavy metals and anion removal in mining wastewater. pH and alkalinity played an important role to coagulate heavy metals such as Al, and Fe and an anion such as ${SO_4}^{2-}$ with silica matrix as well as NaOH. However, the efficiency to form coagulates was much greater in silica matrix-treated wastewater than NaOH-treated one. Fe in wastewater formed coagulation with both silica matrix and NaOH treatments resulting in lowering Fe content in wastewater at above pH 9. For Al removal in wastewater, silica matrix-treated wastewater at above pH 12.3 formed stable coagulate with Al, while NaOH-treated one did not. Alkalinities of 89 and 220 mg/L were required to stabilize silica matrix treated coagulate with Fe and Al, respectively. Reaction time of ten minute was required to provide enough reaction for coagulation between heavy metals and silica matrix. Heavy metals and anion leachates were much lower in coagulate with silica matrix than that with NaOH, which indicates that silica matrix could be used to remove heavy metals efficiently.

• Membrane and Water Treatment
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• v.5 no.2
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• pp.109-122
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• 2014

Polyvinylidene fluoride (PVDF) hollow fiber membrane is widely used for water treatment. However, the weak mechanical strength of PVDF limits its application. To enhance its tensile strength, a double-layer composite hollow fiber membrane, with PVDF and polyetherimide as the external and inner layers, respectively, was successfully prepared through phase inversion technique. The effects of additive content, air gap distance, N,N-dimethyl-acetamide content in the inner core liquid, and the temperature of external coagulation bath on the membrane structure, permeation flux, rejection, tensile strength, and porosity were determined. Experimental results showed that the optimum preparation conditions for the double-layer composite hollow fiber membrane were as follows: PEG-400 and PEG-600, 5 wt%; air gap distance, 10 cm; inner core liquid and the external coagulation bath should be water; and temperature of the external coagulation bath, 40 C. A single layer PVDF hollow fiber membrane (without PEI layer) was also prepared under optimum conditions. The double-layer composite membrane remarkably improved the tensile strength compared with the single-layer PVDF hollow fiber membrane. The permeation flux, rejection, and porosity were also slightly enhanced. High-tensile strength hollow fiber PVDF ultrafiltration membrane can be fabricated using the proposed technique.

• Textile Coloration and Finishing
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• v.30 no.4
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• pp.321-328
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• 2018

Wet polyurethane resin was synthesized by using polytrimethylene ether glycol prepared from 1,3-propanediol produced by fermentation from corn sugar as bio polyol and polyether-polyol(PTMG). Physical properties and cell characteristics by wet coagulation were investigated using the synthesized wet polyurethane resin. The tensile strength of wet polyurethane resin decreased with increasing content of bio polyol as copolymer polyol, but it tended to increase elongation at break and tear strength. As a result of thermal characteristic analysis, it was found that the glass transition temperature was slightly increased as the content of bio polyol increased. As a result of comparing the cell characteristics by the wet coagulation method, it was found that the shape of the cell was good when the ether polyol and the bio polyol were used alone.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.258-262
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• 2001

In the advanced age, cardiovascular disease is more serious than any other disease. Especially, the thrombus causes the serious disease like apoplexia, carebri and myocardial infarction. Thrombosis is caused by the injury of endothelium and the alterations in normal blood flow. To investigate activities of Carthamus tinctorius L. Semen butanol fraction for blood coagulation system, endotoxin (4000EU/kg) was injected (i..v) to rats at 1hr after administration of Carthamus tinctorius L. Semen butanole fraction (500 mg/kg, p.o.). Carthamus tinctorius L. Semen butanol fraction was found to have antiplatelet activity in vitro. In vivo it showed a delay of blood clotting time, and prothrombin time, and reduction of fibrinogen and FDP It also increased SOD activity, and decreased MDA content. These results suggest that the antithrombosis effect of Carthamus tinctorius L. Semen butanol frac tion results from suppressive activity for a blood coagulation system and antioxidative activity.