• Proceedings of the Microbiological Society of Korea Conference
• /
• 2003.05a
• /
• pp.111-114
• /
• 2003

The dynamics of microbial community structure of the various domestic wastewater treatment processes were examined using a novel approach of quinone profiles. The compositions of microbial quinone of 5 sites fer plant and lab-scale activated sludge were analyzed. More than 14 kinds of quinones were observed in the activated sludges tested in this study. The microbial community structure of the plant activated sludge processes a little differed from that of the lab-scale submerged MBR systems. The dominant quinones were UQ-8, UQ-10 followed $MK-8(H_4)$, MK-7 and MK-6. The molar ratio of ubiquinones to menaquinones (UQ/MK) changed from 0.81 to 1.9, indicating that aerobic bacteria dominated the microbial community of the activated sludge examined. The microbial diversity of the activated sludges calculated from the all quinone compositions was 9.5-11.9 and the microbial equability of the activated sludges was 0.64-0.79.

• Journal of the Korean Society for Heat Treatment
• /
• v.7 no.1
• /
• pp.35-43
• /
• 1994

For the purpose of studying the change of mechanical properties of weld parts, shielded metal are welding, one-pole and two-pole submerged arc welding were accomplished weldability on $60kg/mm^2$ quenched and tempered high strength steel. Charpy impact values of the weld metal in welded parts by SMAW and SAW were lower than those of the heat affected zone and increased in order of bond, coarsened, refined and carbon spheroidized regions in the heat affected zone. Grain size of prior austenite or M-A constituent did not significantly affect toughness of welded parts, but precipitated carbide films which forms at the grain boundaries or within matrix and volume fraction of pearilte were most important factor for toughness.

• Journal of Korean Society on Water Environment
• /
• v.23 no.1
• /
• pp.1-11
• /
• 2007

The low nutrient environment in drinking water treatment plants and distribution systems cannot to be a good environment for bacterial growth. However, biofilms can be frequently found submerged surface in treatment plants and distribution system. Biofilms in distribution system are harmful, in that they can release organisms, and may cause problems in taste and odor of water. Control of these Biofilms is difficult, and disinfection alone is usually ineffective. Biofilms will not be eliminated from distribution systems by any contemporary technology available now or in the future. Therefore reduction of organic matter, improved disinfection, or a combination of these methods can be useful in controlling distribution system biofilms.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.3
• /
• pp.352-358
• /
• 2009

The physicochemical properties of dextran culture fermented by Leuconostoc citreum S5 were evaluated by the addition of various polysaccharides and heat-treatment. The consistency of dextran culture increased with the addition of carrot juice residue (CJR) in submerged culture, resulting in the highest consistency of 150 $Pa{\cdot}s^n$ and viable cell counts of $2.36{\times}10^9$ CFU/mL at 20% level of CJR. The dextran culture showed the pseudoplastic behavior and its consistency was greatly increased with the addition of various polysaccharides at 2% level. Addition of glucomannan indicated the highest consistency of 1275 $Pa{\cdot}s^n$ and their heat-treatment resulted in the increase of consistency except for glucomannan. After heat-treatment, the fermented dextran culture containing CJR fortified with gellan gum and carrageenan showed great change in rheology, indicating the highest consistency and hardness value resulted in the great increase of elastic and viscous moduli. The dynamic viscoelastic properties of dextran culture were greatly increased by the heat-treatment after fortification of various polysaccharides. Thus, the consistency and viable cell counts of dextran culture were increased with the addition of CJR. The rheological properties of dextran culture were manipulated by the fortification of various polysaccharides and heat-treatment.

• Environmental Engineering Research
• /
• v.14 no.3
• /
• pp.174-179
• /
• 2009

The InSub system(applied for a patent) was developed, as it combined the indirectly aerated submerged biofiltration(InSub) reactor and Anaerobic/ Anoxic reactor. This system which can eliminate organism and nutrient materials at the same time, which is safe and economical to be maintained and managed is more simple process than the complicated existing biological advanced sewage treatment system. The most suitable HRT of this study showed 9 hours. As looking into the effluent concentration and removal efficiency of each item at 9 hours of HRT, each effluent concentration for $SS,\;BOD5,\;COD_{Mn},\;and\;COD_{Cr}$ was 1.46 mg/L, 7,09 mg/L, 9.84 mg/L and 16.42 mg/L. And their removal efficiency was 96.98%. 90.59%, 77.18% and 83.92%, respectively. Each effluent concentration of T-N and T-P was 10.42 mg/L and 1.04 mg/L. Their removal efficiency was 73.38% and 61.62%, respectively. This pilot plant experiment(the state was without the internal recycling.) followed a variety of HRT. The results confirmed that it was to be advanced sewage treatment system with high efficiency when it combined with the internal recycling.

• Asian Journal of Turfgrass Science
• /
• v.1 no.1
• /
• pp.30-36
• /
• 1987

In order to promote the germination of Korean lawn grass(Zoysia japonica Steud.) seeds a gravimetric seed selection with a mixed chemical solution and the germination promotion with KOH treatment were studied and following results were obtained. 1. When immersed into methanol(S.G., 0.7) 14 percent of immature seeds were precipitated. 2. With water (S.G., 1.0) 36.5 percent of mature seeds were submerged. 3. On a mixture of carbon tetrachloride (S.G., 1.6) and ethylether (S.G., 0.7) in a ratio of 4:6 the seed selection was most effective. 4. When treated with KOH solution the germination rate was 71.01 percent in contrast to 6.0 percent of germination without the treatment. 5. As for concentration of KQH solution, 15 percent depressed the germination (46.7 %) whereas above 20 % the germination rate was gradually increased (79.32 %) up to 40 percent of concentration where the concentration started to depress germination ratio (77.32 %). 6. Finally, in connection with the duration of KOH treatment, a time lapse of up to 20 minutes depressed the germinating ratio(70.02 %) and 30 minutes to 45 minutes increased this ratio to 94.52 percent. 60 minutes of treatment depressed the germination to 75.62 percent.

• Membrane Journal
• /
• v.18 no.2
• /
• pp.157-167
• /
• 2008

Removal of organic substances and taste/odor control are ones of the main issues in water supply, resulting in introduction of advanced processes such as ozon/GAC, or PAC. However, raw water quality deteriorates, new pollutants advent, so water quality is not acceptable enough even with those existing advanced processes. In this paper, a new advanced water treatment process using PAC slurry blanket, where PAC particles stay in the basin as slurry blanket, coupled with submerged membranes is introduced. A pilot plant $(80m^3/day)$ was installed to assess the performance of this new process using actual raw water, and DOC was removed higher than 90% in the beginning and $70{\sim}80%$ afterwards, while 2-MIB and geosmin were removed completely. This new process still requires future study on process optimization and long-term assessment, however it seems highly possible to countermeasure as a new advanced process with high removal efficiency.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.2
• /
• pp.156-160
• /
• 1997

The combination of biological wastewater treatment process and membrane separation has many advantages such as better effluent quality and system stability over the conventional biological wastewater treatment process. In this study, direct membrane separation using nonwoven fabric was applied to biological wastewater treatment. A nonwoven fabric module was submerged in the aerated bioreactor. And accumulated biomass in the bioreactor was separated by suction. The system was operated with various condition to investigate pollutant removal efficiencies and flux. After formation of biomass layer on nonwoven fabric surface, a day, the stable effluent water quality was obtained. The flux decreased at a high suction pressure faster than a low pressure. The stable flux was obtained at the pressure of $21{\sim}25cmHg$. In spite of variation of hydraulic retention time, organic loading rate, the removal efficiencies of BOD, $COD_{Cr}$. $COD_{Mn}$ were very high as follows : $95.2%(0.14{\sim}0.97\;BODKg/m^3/day)$, $86.0%(0.17{\sim}1.39\;COD_{Cr}Kg/m^3/day)$, $90.0%(0.097{\sim}0.61\;COD_{Mn}Kg/m^3/day)$.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.35 no.2
• /
• pp.112-123
• /
• 2013

This study aims to investigate the clinical outcome following treatment of peri-implantitis lesions. Five subjects with 7 implants were treated with surgical approach. Four subjects with 6 implants were initially treated with non-surgical approach or hygiene control. However, inflammation was not resolved and more bone loss was found. Therefore, surgical treatment was performed. After surgical exposure of the defect, granulation tissue was removed and implant surface was treated using tetracycline and chlorhexidine. Then, the flaps were sutured. The wound healing was performed in a non-submerged mode. The present finding demonstrates stable results without progression of bone loss. In one subject, deep V shaped bone defect was filled with bone substitute (ICB, CanCellous Bone, Rockey Mountain Tissue Bank, USA), and resorbable membrane (Lyoplant$^{(R)}$, B.Braun Aesculap AG, Germany) was placed over the grafted defect and healing abutment was connected. However, the inflammation was not resolved and more bone loss was found. At one month after regenerative surgery, the implant was removed.

• Membrane Journal
• /
• v.15 no.3
• /
• pp.241-246
• /
• 2005

This study is investigated for the applications of MBR SYSTEM using $ENVIS^{(R)}$ which is a submerged flat membrane for treatment of sewage and wast water. The experiment was practiced on the scene of labor that are sewage facilities of factories $(10\;m^3/day)$ and wast water treatment plant $(30\;m^3/day)$ using equipments made by Pure-Envitech Co., LTD. SS, BOD and COD for the result of removal efficiency at the sewage facilities of factories were $99.7\%,\;97.6\%$, and $96.8\%$, rspectively. SS, BOD and COD for the result of removal efficiency at the waste water treatment plant were $99.6\%,\;95.6\%,\;and\;80.3\%$, respectively.