• 기술사
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• 제28권5호
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• pp.20-24
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• 1995

• 한국산업융합학회 논문집
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• 제9권2호
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• pp.111-116
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• 2006

This study provides the optimal conditions treating with the coagulation process and the other chemical treatment processes for dyeing wastewater, especially various dyeing complex wastewater. The results are shown as follows: 1. Optimum reaction condition of pH for ferrous sulfate was the range of 9 to 12. And when 3,000ppm(mg/l) of ferrous sulfate was dosed, the maximum $COD_{Mn}$ removal rate was approximately 40%. 2. In case of ferrous chloride and Bittern as coagulants, optimum pH range was 10 to 11. And maximum $COD_{Mn}$ removal rate was approximately 46% to 50% for dose of 2,000ppm(mg/l) to 6,000 ppm. 3. It is confirmed that the activated sludge process following coagulation precipitation method provides better treatment efficiency than the coagulation precipitation method following the activated sludge process. 4. The purpose of this study was to produce CGF (Cyanoguanidineformaldehyde resin) by organic compounds. 5. The complex coagulation agent by this study is the most economical coagulant with Alum(aluminum sulfate) and the removal efficiency is approximately 54% with 1,000ppm(mg/l) of pH range 6 to 7.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1212-1220
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• 2013

The human coagulation factor XI (FXI) is a serine protease that plays a significant role in blocking of the blood coagulation cascade as an attractive antithrombotic target. Selective inhibition of FXIa (an activated form of factor XI) disrupts the intrinsic coagulation pathway without affecting the extrinsic pathway or other coagulation factors such as FXa, FIIa, FVIIa. Furthermore, targeting the FXIa might significantly reduce the bleeding side effects and improve the safety index. This paper reports on a docking-based three dimensional quantitative structure activity relationship (3D-QSAR) study of the potent FXIa inhibitors, the chloro-phenyl tetrazole scaffold series, using comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) methods. Due to the characterization of FXIa binding site, we classified the alignment of the known FXIa inhibitors into two groups according to the docked pose: S1-S2-S4 and S1-S1'-S2'. Consequently, highly predictive 3D-QSAR models of our result will provide insight for designing new potent FXIa inhibitors.

• 한국물환경학회지
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• 제29권2호
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• pp.170-175
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• 2013

Achieving very low phosphorus levels in treated wastewater will require the installation of additional treatment. Phosphorus removal experiments by chemical coagulation were carried out for the effluent of wastewater treatment plant in this study. TP (total phosphorus) or phosphate were highly related to the addition of PAC (poly aluminium chloride) which is one of the inorganic coagulants. But, organic polymer did not significantly affect the phosphorus removal efficiency. Polymer affected the flocculation of particle especially particle matter less than 10 micrometer so, the number of micro particles was decreased by polymer dose. Chlorination would not affect on chemical coagulation process and TP and turbidity could be effectively removed by the co-addition of PAC and polymer.

• 한국축산식품학회지
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• 제30권4호
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• pp.551-559
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• 2010

Among the food constituents, proteins differ in coagulation properties as compared to other constituents in food system. Especially milk protein coagulate through different pathways thus this coagulability can be used for manufacture of various dairy products or as a determinant of dairy product analysis. These milk coagulation methods include organic solvent, isoelectric point, trichloroacetic acid, Ca-sensitive casein, heavy metal ion and rennet coagulation. The coagulation experiment was performed using above parameters at $0^{\circ}C$ and $25^{\circ}C$ to find the dehydration conditions before coagulating for precheese powder making. After different chemical treatments, there was no coagulation at $0^{\circ}C$ rather at $25^{\circ}C$ whatever the mode of coagulation methods was. The appearance of precipitate with coagulation methods was quite different from above mentioned methods of coagulation illustrated by scanning electron microscope. These powders were used for fabrication of camembert cheese by renneting coagulation at $0^{\circ}C$, showing the possibility of cheese materials and of food additives for fabrication of products.

• 한국염색가공학회지
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• 제12권2호
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• pp.96-102
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• 2000

For the effective treatment of dyeing-complex wastewater, the most effective chemical coagulation method was studied. For the chemical coagulation of dyeing-complex wastewater, polyferric sulfate, $4Al_2(SO_4)_3$, PAC, ferrous sulfate, ferric sulfate, $FeCl_2$ and lime were used. It was investigated that polyferric sulfate was the most efficient coagulant. The optimal conditions and results for polyferric sulfate include the followings. When initial $COD_{Mn}$ concentration was 600mg/L, the optimal initial pH, dosage of coagulant, dosage of lime and PAA for $COD_{Mn}$ removal efficiency were 5, 1,200mg/L, 500mg/L and lmg/L, respectively. The optimal dosage of polyferric sulfate was increased proportionally to the influent $COD_{Mn}$ concentration.

• Advances in environmental research
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• 제3권4호
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• pp.293-306
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• 2014

The present study primarily focuses on the evaluation of the comparative effect of chemical coagulation and ultrasonication for elimination of aromatic amines (AAs) present in anaerobically pretreated textile wastewater containing different types of dyes including azo dyes. Color and COD reduction was also monitored at the optimized conditions. The production of AAs was measured spectrophotometrically in the form of total aromatic amines (TAAs) and also verified with high performance liquid chromatography (HPLC) selectively. A composite coagulant, magnesium chloride (MC) aided with aluminium chlorohydrate (ACH) in an equal ratio (MC + ACH) was utilized during the coagulation process, which yielded 31% of TAAs removal along with 85% of color and 52% of COD reduction. At optimized power (200 W) and sonication time (5 h), an appreciable TAAs degradation efficiency (85%) was observed along with 51% color reduction and 62% COD removal using ultrasonication. The chromatographic data indicate that sulphanilic acid and benzidine types of aromatic amines were produced after the reductive cleavage of utilized textile dyes, which were effectively mineralized after ultrasonication. The degradation followed the first order kinetics with a correlation coefficient ($R^2$) of 0.89 and a first-order kinetic constant (k) of $0.0073min^{-1}$.

• 한국환경보건학회지
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• 제27권4호
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• pp.93-98
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• 2001

Wastewaters produced in textile industrial processes contain dyes which are not easily amenable to biological treatment. The object of this study is to determine the post-treatment system of biological process for the textile wastewater by comparing three different types of chemical process, which were 1) post-treatment by ozone or UV, 2) post-treatment by coagulation,3) post-treatment by ozone or UV followed by coagulation. In an application ozone or UV as a post-treatment, color was generally decreased with time, however, SCOD removal effect was not that good. When coagulation was used as point-treatment process, the effluent quality was satisfying. Therefore, the application of coagulation process as a post-treatment of biological process would be more desirable than that as a ozone or UV.

• 상하수도학회지
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• 제24권4호
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• pp.463-474
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• 2010

In this study, chemical coagulation conditions for treating combined sewer overflow(CSO) occurred during rainy season were evaluated by jar tests with aluminum sulfate[$Al_2(SO_4)_3{\cdot}17H_2O$] and ferric chloride[$FeCl_3{\cdot}6H_2O$]. The raw domestic sewage sampled from the primary sedimentation tank at a local sewage treatment plant was filtered through $150{\mu}m$ sieve before using. Point of zero charge(PZC) for various dose of aluminum sulfate occurred at pH 5.8-6.5, while for ferric chloride occurred at pH 5.3-6.0 in term of streaming current(SC) values. Charge neutralization ability of aluminum sulfate was bigger than that of ferric chloride. Optimum pH and dose of aluminum sulfate and ferric chloride were 6.2, 0.438mM and 5.8, 0.925mM, respectively. Removal efficiencies of TCOD, turbidity, SS and TP were 75, 97, 95, 96% with aluminum sulfate and 74, 96, 98, 99% with ferric chloride at their optimum coagulation conditions. More efficient removal of SS, TP and small particles was possible with ferric chloride at optimum coagulation conditions. Both SC values and COD removal started to increase where soluble phosphorus was completely removed.

• 한국물환경학회지
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• 제39권6호
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• pp.465-474
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• 2023

The chemical composition and molecular weight characteristics of dissolved organic matter (DOM) exert a profound influence on the efficiency of organic matter removal in water treatment systems, acting as efficiency predictive indicators. This research evaluated the primary chemical and molecular weight properties of DOM derived from diverse sources, including rivers, lakes, and biomasses, and assessed their relationship with the efficiency of coagulation/flocculation treatments. Dissolved organic carbon (DOC) removal efficiency through coagulation/flocculation exhibited significant correlations with DOM's hydrophobic distribution, the ratio of humic-like to protein-like fluorescence, and the molecular weight associated with humic substances (HS). These findings suggest that the DOC removal rate in coagulation/flocculation processes is enhanced by a higher presence of HS in DOM, an increased influence of externally sourced DOM, and more presence of high molecular weight compounds. The results of this study further posit that the efficacy of water treatment processes can be more accurately predicted when considering multiple DOM characteristics rather than relying on a singular trait. Based on major results from this study, a predictive model for DOC removal efficiency by coagulation/flocculation was formulated as: 24.3 - 7.83 × (fluorescence index) + 0.089 × (hydrophilic distribution) + 0.102 × (HS molecular weight). This proposed model, coupled with supplementary monitoring of influent organic matter, has the potential to enhance the design and predictive accuracy for coagulation/flocculation treatments targeting DOC removal in future applications.