• Proceedings of the Korean Environmental Sciences Society Conference
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• 1997.10a
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• pp.67-67
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• 1997

정수공정은 "원수 -1 침사지 1 전염소 -1 전오존 -1 침전지 1 여과지 1 후오존 1 GAC 4 후염소 1 가정수"로 이루어져 있으며 전처리 공정으로 염 소와 오존을 주입하게 되는데, 여기서 전염소 처리 공정으로 인해 잔류 유리염 소가 수중의 유기물질과 반웅하여 유해성 유기염소 화합물 (i.e.. Trihalomethane, Haloacetonitriles, Chlorophenol 등)을 생성하는 것으로 알려져 있다. 이러한 이유로 고도 정수처리 공정에서는 강한 산화력을 지닌 대체 산화 제로서 오존을 이용하고 있다. 전오존 처리공정은 OOC와 탁도 제거에 있어 응 집제 주입량을 감소시키는 것과 더불어 전오존 효과 (산화, 생분해 증대, 살균 등)를 얻을 수 있는 것으로 알려져 왔다. 그러나 낙동강과 같이 유기물이 많은 원수에 과다한 오존이 주입되면 수중 의 유기물이 저분자화 또는 응집이 어려운 오존 산화물로 변화하여 응집제의 소비가 많아지게 된다. 실제, 오존을 응집 효과에 대해서 pilot plant로 운전한 결과 전오존에 의해 입자성 물질의 제거 효율은 향상된 반면에 유기물 제거는 뚜렷한 효과를 볼 수 없었다고 보고되었다 (류, 1997). 본 연구에서는 물금 지역의 원수와 응집-침전 공정까지 거치는 각각의 처 리수에 대해서 전처리가 응집에 미치는 영향을 천연유기물질 (NOM)의 조성 변화로 파악하였다. 그 방법으로 천연유기물질 (NOM)을 XAD-1, -4 수지를 이 용하여 소수성 물질 (hydrophobic components)과 친수성 물질 (hydrophilic components)로 분리 및 농축하여 용존 유기물이 처리 과정에서 어떻게 변화하 는지를 조사하여 개선된 상수 처리 시스템을 설계하는데 기초 자료를 제공하고 수질 관리 분야에서도 적용하고자 하였다. 상수원수인 물금 지역의 소수성 물질(hydrophobic components)은 75~80%, 친수성 물질(hydrophilic components)은 30~33%정도의 분포를 보였고, 전염소 및 전오존 공정을 거친 처리수에서는 각각 62.2-62.8%, 43.9~49.0% 및 50~ 55%, 40~57% 정도의 분포를 보였다. 그리고 웅집-침전을 거친 처리수에서는 그 분포가 77~82%, 24-48%였다. 전주리 공정을 통하여 소수성 물질(byoghobic components)의 분포가 감 소하는 것을 볼 때 전염소 및 전오존 처리가 용존유기물의 응집에는 오히려 역 효과를 나타내는 것으로 판단된다. 것으로 판단된다.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.445-455
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• 2009

Microbiological sulfate reduction is the transformation of sulfate to sulfide catalyzed by the activity of sulfate-reducing bacteria using sulfate as an electron acceptor. Low solubility of metal sulfides leads to precipitation of the sulfides in solution. The effects of microbiological sulfate reduction on in-situ precipitation of arsenic and copper were investigated for the heavy metal-contaminated soil around the Songcheon Au-Ag mine site. Total concentrations of As, Cu, and Pb were 1,311 mg/kg, 146 mg/kg, and 294 mg/kg, respectively, after aqua regia digestion. In batch-type experiments, indigenous sulfate-reducing bacteria rapidly decreased sulfate concentration and redox potential and led to substantial removal of dissolved As and Cu from solution. Optimal concentrations of carbon source and sulfate for effective microbial sulfate reduction were 0.2~0.5% (w/v) and 100~200 mg/L, respectively. More than 98% of injected As and Cu were removed in the effluents from both microbial and chemical columns designed for metal sulfides to be precipitated. However, after the injection of oxygen-rich solution, the microbial column showed the enhanced long-term stability of in-situ precipitated metals when compared with the chemical column which showed immediate increase in dissolved As and Cu due to oxidative dissolution of the sulfides. Black precipitates formed in the microbial column during the experiments and were identified as iron sulfide and copper sulfide. Arsenic was observed to be adsorbed on surface of iron sulfide precipitate.

• Resources Recycling
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• v.12 no.1
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• pp.33-40
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• 2003

Mn was extracted by using a nitric acid from the reduced ferromanganese dust and the basic experiments were taken to refine the manganese nitrate solution by means of precipitation of Ca, Mg oxalate. The dust was generated in AOD process producing a medium-low carbon ferromanganese and collected in the bag filter. Manganese oxide content in the dust was about 90% and its phase was confirmed as $Mn_3$$O_4$. $Mn_3$$O_4$ in the dust was reduced to MnO by roasting with activated charcoal. The main impurities in the extracted solution prepared by leaching the reduced dust with nitric acid were Na, K, Fe, Si, Ca, Mg etc. Among them, Fe was removed by controlling pH of the solution more than 4 and precipitating $Fe(OH)_3$, simultaneously silicious material solved in the solution was removed by co-precipitation with the ferric hydroxide. Addition of 150 g reduced dust into 4N HNO3 solution 1$\ell$ was appropriate to control the pH of the solution to pH 4. To differ greatly the solubilities of manganese oxalate and calcium or magnesium oxalate in a solution containing a high concentration of Mn, pH of 4 or less and addition of ($NH_4$)$_2$$C_2$$O_4$ in equivalent with Ca and Mg are recommended. At this time, the higher temperature was the shorter the precipitation reaction time was needed.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.575-585
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• 2007

Microbial control of the geochemical behavior of heavy metals (Cd, Cu, Pb, and Zn) and As in contaminated subsurface soil and sediment was investigated through activation of indigenous bacteria with lactate under anaerobic condition for 25 days. The results indicated that dissolved Cd, Pb and Zn were microbially removed from solutions, which was likely due to the formation of metal sulfides after reduction of sulfate by indigenous sulfate-reducing bacteria. Soils from the Dukeum mine containing a large amount of sulfate resulted in complete removal of dissolved As after 25 days by microbial activities, while there were gradual increases in dissolved As concentration in soils from the Hwabuk mine and sediments from the Dongducheon industrial area which showed low $SO_4{^2-}$ concentrations. Addition of appropriate carbon sources and sulfate to contaminated geological media may lead to activation of indigenous bacteria and thus in situ stabilization of the heavy metals; however, potential of As release into solution after the amendment should be preferentially investigated.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.146-149
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• 2013

A 6-month-old, intact male Great Pyrenees (35 kg) was referred with 2 weeks continuous left forelimb lameness to the Chonbuk Animal Medical Center, College of Veterinary medicine, Chonbuk National University. The lameness became worse three days before being referred to the hospital. Upon the physical examination, the patient had pain when the left shoulder joint was palpated, and the lameness was visible in the left forelimb during ambulation on gait examination. There were no remarkable findings on radiological and neurological examination. Osteochondritis dissecans (OCD) was suspected based on medical history and gait tests. As a definitive diagnosis could not be made, exploratory arthroscopic surgery was performed to examine the inside of the shoulder joint. During the operation, mild bicipital tenosynovitis, synovitis and OCD which was located on the caudal medial area of humeral head were revealed. Arthroscopic procedures were used for the treating OCD, including the removal of the OCD flap and debriding of the subchondral defect until hemorrhaging by use of an electrical burr. The patient was discharged a day after surgery. After 2 weeks, the patient again presented at the hospital due to complications, including inflammation of the surgical lesion because of licking and seroma within the subcutaneous tissue. Antibiotics were administered and an aseptic bandage was applied. And simple surgical operations were performed for the removal of the cyst and seroma. Eleven weeks following arthroscopy, the lameness was completely resolved. Arthroscopy has the advantage of allowing gross examination inside the joint capsule. Due to this advantage, arthroscopy is one of the best advanced options for diagnosis in dogs with undiagnosed joint pain.

• Korean Journal of Materials Research
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• v.6 no.5
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• pp.524-531
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• 1996

차세대 소자고립구조로서 연구되고 있는 trench isolation 공정 등에는 실리콘 식각이 요구되며 실리콘 식각 공정중에는 반응성 이온에 의해 격자결함이 발생할 수 있다. 이와같이 생성된 결함은 소자의 전기적 성질을 열화시키므로 열처리를 통하여 제거하여야만 한다. 따라서 본 연구에서는 Ar,Ar/H2 플라즈마로 격자결함을 인위적으로 발생시켜 20$0^{\circ}C$-110$0^{\circ}C$ 질소분위기에서 30분간 열처리에 따른 생성된 격자결함의 소거거동을 관찰하였다. 실리콘 표면에 Schottky 다이오드를 제작하여 I-V, C-V 특성을 측정하므로써 잔류하는 전기적인 손상의 정도를 평가하였다. Ar으로 식각한 경우에는 110$0^{\circ}C$ 30분간 열처리한 결과 모든 격자결함이 제거되나 Ar/H2로 식각한 경우에는 격자결함이 완전히 제거되지 않고 (111)적층결함이 남아있었다.

• Water for future
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• v.22 no.1
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• pp.117-125
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• 1989

This study deals with the performance of an acivated sludge system which is modified by the researcher to function without any additional chemical or internal recyle in removing organics, nitrogen, and phosphorus from synthetic wastewater. To improve the nutrient removal efficiency, the researcher utilized the anoxic, anaerobic, and aerobic reactor sequences with a single sludge return, whiched to nitrification/denitrification and phosphorus release/overplus accumulation. A bench scale system was operated with a view to investigating the reaction characteristics of each reactor, and to measuring the biological kinetic coefficients(Y, $K_d$, k, $K_s$) for theremoval of COD in relation to the mean cell residence time at five different MLSS concentrations, 5000, 4200, 3300, 2600, and 1900 mg/l. The results of the research showed that organic substance and nutrient were removed simultaneously by this modified activated sludge process. And the process kad 66%-99% ortho-p removal efficiency.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1035-1043
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• 2007

A leachate containing an elevated concentration of organic and inorganic compounds has the potential to contaminate adjacent soils and groundwater as well as downgradient areas of the watershed. Moreover high-strength ammonium concentrations in leachate can be toxic to aquatic ecological systems as well as consuming dissolved oxygen, due to ammonium oxidation, and thereby causing eutrophication of the watershed. In response to these concerns landfill stabilization and leachate treatment are required to reduce contaminant loading sand minimize effects on the environment. Compared with other treatment technologies, leachate recirculation technology is most effective for the pre-treatment of leachate and the acceleration of waste stabilization processes in a landfill. However, leachate recirculation that accelerates the decomposition of readily degradable organic matter might also be generating high-strength ammonium in the leachate. Since most landfill leachate having high concentrations of nitrogen also contain insufficient quantities of the organic carbon required for complete denitrification, we combined a shortcut biological nitrogen removal (SBNR) technology in order to solve the problem associated with the inability to denitrify the oxidized ammonium due to the lack of carbon sources. The accumulation of nitrite was successfully achieved at a 0.8 ratio of $NO_2^{-}-N/NO_x-N$ in an on-site reactor of the sequencing batch reactor (SBR) type that had operated for six hours in an aeration phase. The $NO_x$-N ratio in leachate produced following SBR treatment was reduced in the landfill and the denitrification mechanism is implied sulfur-based autotrophic denitrification and/or heterotrophic denitrification. The combined leachate recirculation with SBNR proved an effective technology for landfill stabilization and nitrogen removal in leachate.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.155-158
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• 1999

Recently arthroscopic procedure was introduced into an effective method when chronic gouty arthritis associated with acute inflammation is unresponsive to conservative treatment. The purpose of this study is to cvaluate the efficacy of tophi excision during this procedure. We tried to excise tophi which were known as one of causative materials of acute inflammation as much as possible. We report one case of chronic tophaceous gouty arthritis of the right knee which was satisfactorily treated without recurrence during more than one year after this arthroscopic procedure.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.386-389
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• 2004

Descending nectorizing mediastinitis (DNM). represents a virulent form of mediastinal infection requiring prompt diagnosis and treatment to reduce the high morbidity mortality associated with this disease. Intr. avenous broad-spectrum antibiotic therapy alone is not efficient without adequate surgical drainage of the cervical and mediastinal collections, extensive debridement and excision of necrotic tissue, and wide mediastino-pleural irrigation. A 38-year-old man admitted via emergency room with painful left neck swelling and uncontrolled high fever. Chest computed tomogram showed left paratracheal abscess descending into the superior and anterior mediastinum. Transcervical mediastinal drainage was performed with 26 Fr. chest tube and left paratracheal drainage was performed with Penrose drain in urgency. Culture and sensitivity test grew Yeast. The drains removed via gradually shortening on day 39 after surgery.