• 상하수도학회지
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• 제21권1호
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• pp.91-99
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• 2007

It is well-known that the presence of NOM (natural organic matter) in water has a negative effect on removing taste and odor compounds by activated carbon adsorption. Therefore, various means such as enhanced coagulation are applied to reduce the NOM. The presence of taste & odor compounds in drinking water even parts per trillion, is enough to generate customer dissatisfaction. Therefore, the aim of this study was to evaluate carbon usage rate (CUR) for conventional coagulation (CC) and enhanced coagulation (EC) in order to improve the efficiency of adsorption of taste and odor compounds. Also, Effect of CC and EC on molecular weight fraction and the early stage breakthrough of 2-MIB and Geosmin are evaluated. When the enhanced coagulation was adapted for pretreatment for activated carbon adsorption the operation period could be prolonged by 3.5~4 times. CUR for CC was about 2 times greater than CUR for EC and this means that EC has more adsorption capacity than CC. To analyze effect of EC and CC on breakthrough of 2-MIB quantitatively, adsorbed NOM mass was calculated based on unit mass of activated carbon. In the early stage breakthrough of 2-MIB, total adsorbed NOM was 23.72mg/g for CC and 34.56mg/g for EC. Therefore, it is shown that the early breakthrough term of 2-MIB and Geosmin was improved due to increased adsorbability. The low-molecular-weight NOM (500~2000Da) compounds were the most competitive, participating in direct competition with 2-MIB for adsorption site.

• Journal of Trauma and Injury
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• 제34권3호
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• pp.191-197
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• 2021

Renal injuries occur in more than 10% of patients who sustain blunt abdominal injuries. Non-operative management (NOM) is the established treatment strategy for lowgrade (I-III) renal injuries. However, despite some evidence that NOM can be successfully applied to high-grade (IV, V) renal injuries, it remains unclear whether NOM is appropriate in such cases. The authors report two cases of high-grade renal injuries that underwent NOM after embolization in a hybrid emergency room (ER) system with a 24/7 in-house interventional radiology (IR) team. A 29-year-old male visited Wonkwang University Hospital Regional Trauma Center complaining of right abdominal pain after being hit by a rope. Computed tomography (CT) was performed 16 minutes after arrival, and the CT scan indicated a grade V right renal injury. Arterial embolization was initiated within 31 minutes of presentation. A 56-year-old male was transferred to Wonkwang University Hospital Regional Trauma Center with a complaint of right flank pain. He had initially presented to a nearby hospital after falling from a 3-m height. Thanks to the key CT images sent from the previous hospital prior to the patient's arrival, angiography was performed within 8 minutes of the patient's arrival and arterial embolization was completed within 25 minutes. Both patients were treated successfully through NOM with angioembolization and preserved kidneys. Hematoma in the first patient and urinoma in the second patient resolved with percutaneous catheter drainage. The authors believe that the hybrid ER system with an in-house IR team could contribute to NOM and kidney preservation even in high-grade renal injuries.

• 대한환경공학회지
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• 제37권5호
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• pp.269-276
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• 2015

본 연구는 경상북도 지역에서 호소수를 원수로 사용하는 한 정수장의 원수 및 공정별 처리수의 자연유기물질(NOM) 및 소독부산물(DBPs) 생성특성을 조사하고 정수공정내 DBPs 제어방안을 제시하였다. Fluorescence excitation-emission matrix (FEEM) 분석결과 원수의 NOM은 토양과 미생물의 복합기원에 의한 것으로 밝혀졌다. NOM의 분자량크기 및 분획제거 특성은 liquid chromatography-organic carbon detector (LC-OCD)를 이용하여 분석하였다. 대체로 휴믹물질과 저분자량 유기물질 분획이 많았고, 고분자량물질은 저분자량물질보다 응집 침전공정에서 제거가 용이한 것으로 나타났다. 전염소주입 후 정수공정별로 진행될수록 반응시간이 길어져 DBPs 농도가 증가하였으며 생성된 DBPs는 일반적인 정수처리로 제거되지 않았다. THMs은 chloroform이 74%로 주종을 이루었으며 bromodichloromethane (22%)와 dibromochloromethane (4%)도 발생했다. HAAs는 dichloroacetic acid (50%)와 trichloroacetic acid (48%)가 주종을 이루었고 dibromoacetic acid (2%) 등 브롬계열은 농도가 낮거나 발생되지 않았다. HANs은 dichloroacetonitrile (60%), bromochloroacetonitrile (30%), dibromoacetonitrile (10%)이 발생되었다. 실험기간 동안 해당 정수장에서 DBPs 발생은 용존유기물농도와 수온보다 전염소주입농도에 큰 영향을 받은 것으로 나타났고, 염소주입농도의 조절로 DBPs 생성농도를 이전에 비해 16~44% 감소시킬 수 있었다.

• Journal of Trauma and Injury
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• 제30권3호
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• pp.91-97
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• 2017

Purpose: Purpose: The prognostic factors of non-operative management (NOM) in high-grade spleen injuries have been extensively studied, but factors that would help treatment decisions are lacking. We compared the characteristics of the patients to identify the factors affecting treatment choices. Methods: This is a review of 207 blunt spleen injury patients from January 2004 to December 2013. We compared clinical features and mortality between surgery and NOM, and used multivariate regression analysis to find the factor most strongly associated with prognosis. Results: Of the 207 patients, 107 had high-grade spleen injury patents (grade III or above). Of these, 42 patients underwent surgery and 65 patients underwent NOM. The mortality was 7% following surgery, 3% with NOM. The amount of packed red blood cells transfused in the first 24 hours and spleen injury grade were associated with management type, and mortality was highly associated with activated partial thromboplastin time (aPTT) and spleen injury grade. Conclusions: The grade of spleen injury was associated with management and mortality, so correctly assessing the spleen injury grade is important.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.68-71
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• 2004

Effects of surfactants and natural organic matter (NOM) on the sorption and reduction of tetrachloroethylene (PCE) and chromate with iron were examined in this study. PCE and chromate reduction by iron depended on the ionic type of the surfactants in this study. The apparent reaction rate constants of PCE with Triton X-100 and hexadecyltrimethyl ammonium (HDTMA) at one half and two times of the critical micelle concentration (CMC) were relatively higher than without surfactants because of the enhanced PCE partitioning and surface concentration. In the presence of sodium dodecyl benzene sulfonate (SDDBS) at 2000 mg/L and NOM at 50 mg/L, the apparent reaction rate constants of PCE increased, but TCE production decreased. The enhanced removal rate of PCE was not due to the dechlorination, and the sorption was dominant iron with SDDBS and NOM. The apparent reaction rate constants of chromate by iron with Triton X-100 and NOM were 1.4-3.1 times lower than without surfactants while that with HDTMA was two times higher than without HDTMA, When the sorbed HDTMA molecules form admicelles, negatively-charged chromate has an affinity for the positively-charged HDTMA head group.

• 멤브레인
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• 제14권2호
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• pp.149-156
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• 2004

본 연구에서는 광촉매 반응과 막분리 기술을 접목시킨 혼성 고도 정수처리 공정에서 소독 부산물의 전구체로 알려진 자연산 유기물을 효과적으로 제거하고자 하였고 다양한 운전 조건에서 시스템의 성능을 비교 평가하였다. 자연산 유기물은 흡입여과 방식의 분리막과 TiO$_2$ 광촉매를 이용하여 광분해하였을 때 광촉매 투입량의 증가에 따라 반응속도가 증가하였지만 과량의 촉매 주입시에는 반응 속도 향상에 오히려 부정적으로 작용하였다. 자연산 유기물을 보다 효과적으로 제거하기 위해 산화철 주입, TiO$_2$ 표면처리, 분리막 표면코팅을 시도하여 제거특성 및 운전에 따른 막여과 특성을 평가하였다. 산화철 주입은 초기에 흡착작용으로 인해 제거율 증가를 보였으나 반응이 진행됨에 따라 산화철 입자에 의한 광산란으로 광분해 효율이 오히려 감소되었다. 산화철 입자에 의한 광산란을 제어하고자 TiO$_2$ 표면을 광처리와 열처리 방법을 이용해 철을 직접 부착시킨 경우 긍정적인 효과를 얻지 못했다. 그러나 산화철로 막표면을 코팅하여 광산란 효과를 배제시킨 경우에는 향상된 결과를 보였다 막투과 플럭스 15 L/$m^2$-h에서 정밀여과를 수행하였을 때 TiO$_2$나 산화철에 의한 막오염은 거의 일어나지 않았고 안정된 막투과도를 나타내었다.

• 한국물환경학회지
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• 제24권6호
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• pp.682-689
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• 2008

The purpose of this study was to find out the variation between molecular size distribution (MSD) of natural organic matter (NOM) in raw waters after different water treatment processes like conventional process (coagulation, flocculation, filtration) followed by advanced oxidation process (ozonation, GAC adsorption). The MSD of NOM of Suji pilot plant were determined by Liquid Chromatography-Organic Carbon Detection (LC-OCD) which is a kine of high-performance size-exclusion chromatography (HPSEC) with nondispersive infrared (NDIR) detector and $UV_{254}$ detector. Five distinct fractions were generally separated from water samples with the Toyopearl HW-50S column, using 28 mmol phosphate buffer at pH 6.58 as an eluent. Large and intermediate humic fractions were the most dominant fractions in surface water. High molecular weight (HMW) matter was clearly easier to remove in coagulation and clarification than low molecular weight (LMW) matter. Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW. No more distinct variation of MSD was observed by ozone process after sand filtration but the SUVA value were obviously reduced during increase of the ozone doses. UVD results and HS-Diagram demonstrate that ozone induce not the variation of molecular size of humic substance but change the bond structure from aromatic rings or double bonds to single bond. Granular activated carbon (GAC) filtration removed 8~9% of organic compounds and showed better adsorption property for small MSD than large one.

• 한국물환경학회지
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• 제21권2호
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• pp.125-131
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• 2005

Natural organic matter(NOM) is defined as the complex matrix of organic material and abundant in natural waters. It affects the performance of unit operations for water purification. Several kinds of analytical indicators such as DOC, specific ultraviolet absorbance(SUVA), apparent molecular weight (AMW), fractionation and high performance size exclusive chromatography(HPSEC) have been used to understand characteristics and variations of NOM. This study aims to evaluate the characteristics of NOM in the Geum River system comprising with stream flows and reservoirs. It was identified that SUVA denoting the portion of humic substance in water ranged within 1.60~3.36. Using resin adsorbents, dissolved organic carbon(DOC) was fractionated into three classes: hydrophobic bases(HOB), hydrophobic acids(HOA) and hydrophilic substances(HI). HI dominates in all samples, collectively accounting for more than 62% of the DOC. HOA was the second dominated fraction and it varied considerably but accounted for about 30% of the DOC. The distribution of high molecular weight(HMW) measured by HPSEC being used to determine the molecular weight distribution of aquatic humic substances was 40.1% and 38.7% in reservoir and stream flow, respectively. The distribution of low molecular weight(LMW) in stream flow was 13.2% higher than that in reservoir. And apparent molecular weight less than 1KDa, which include the molecular weight of hydrophilic organic matter, occupied with 69.2% and 68.2% in stream flow and reservoir, respectively. While the molecular weight of 1 to 100 KDa including humic substances ranged with 18.6% and 21.6% in stream flow and reservoir, respectively. Seasonal variation of refractory dissolved organic carbon was similar to that of SUVA.

• 생명과학회지
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• 제10권1호
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• pp.14-21
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• 2000

음요수 중의 유기탄소의 제거수단으로써 biofiltration법의 타당성을 검토하였다.NOM에서의 생분해 가능한 분율을 알아보기위하여 행하여 졌다. UV 조사량을 3가지로 달리하였을 경우에 회분식에서의 생분해능과 비교하였다. 생물여과 반응기 실험의 경우에 생분해 특성을 검토한 결과 EBCT, 순환비 및 유입농도등과 같은 운전피라미터들이 생물여과 반응기의 생분해능에 영향을 미침을 알 수있었다. 생물여과 반응기의 유출수에서의 UV/DOC의 비는 반응기에 공급되는 원료중의 UV/DOC비에 비해 증가하였으며, 이로부터 생분해에 의해 저거된 DOC는 UV에 의해 그다지 흡수되지 않는 물질임을 알 수있었다. 본 여눅를 통해 생분해 가능한 DOC의 부분을 제거하는데 있어서 생물여과공법이 효과적인 방법이라는 것을 알수있었으며 UV처리와 bilfiltration을 연계한 공정은 수처리 시설에서 유출수의 DOC농도는 낮추는데 효과적인 한가지 방안으로 사료되었다.

• 공업화학
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• 제17권2호
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• pp.119-124
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• 2006

물 속에 존재하는 자연 유기물의 성분은 계절과 장소에 따라 다양하게 변하므로 이들 성분에 대한 고찰과 이들이 환경에 미치는 영향을 고찰할 필요가 있다. 본 총설에서는 물 속에 존재하는 휴믹 물질, 탄수화물, 단백질(아미노산), hexosamine, 유지, 오일, 그리스 및 미량 유기물질(내분비교란화학물질과 의약품) 등의 자연 유기물의 특성을 정리하였다.