• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.23-25
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• 2002

This study was conducted to understand characteristics of wastewater which is discharged from small-scale dyehouse located in Seoul downtown area and to Find the appliable treatment method on the spot. The results of this study were summarized as followings. 1. The method which is used at present is mostly flocculation by coagulant or fenton oxidation. But the treatment efficiency of them are not good. 2. The results of fenton oxidation experiment demonstrated that treatment efficiency of COD was limited, which showed the need of the additional process or the improvement of existing treatment method, while the color was reduced considerably in optimal condition. 3. The optimal condition of fenton oxidation are as followings. -Feasible pH was in the 3∼4 regardless of the kinds of iron ions, But the fluctuation of treatment efficiency with the change of pH was small - The mass ratio of H$_2$O/CODcr was used to evaluate the parameter of H$_2$O$_2$ The optimal range of this was in 0.7∼1,3 and it was observed that the ratio got higher as the quality got worse. -For iron ion, FeCl$_2$4H$_2$O turned out to be more effective for removal of color compared with was compared FeSO$_4$7H$_2$Oin. the mass ratio of Fe/H$_2$O$_2$ of 2.3∼2.8 for of FeSO$_4$7H$_2$O and 1.6∼1.8 for FeCl$_2$4H$_2$O resulted in good treatment efficiencies. 4. With adsorption process applied before fenton oxidation in order to treat the high concentration wastewater, the treatment efficiency increased by 61％ in CODcr, 55％ in color. and if the power activated carbon is injected in more than 2500mg/$\ell$, the wastewater can be treated within the effluent quality criteria.

• 생태와환경
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• 제49권2호
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• pp.67-79
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• 2016

Cyanotoxins in aquatic ecosystems have been investigated by many researchers worldwide. Cyanotoxins can be classified according to toxicity as neurotoxins (anatoxin-a, anatoxin-a(s), saxitoxins) or hepatotoxins (microcystins, nodularin, cylindrospermopsin). Microcystins are generally present within cyanobacterial cells and are released by damage to the cell membrane. Cyanotoxins have been reported to cause adverse effects and to accumulate in aquatic organisms in lakes, rivers and oceans. Possible pathways of microcystins in Lake Suwa, Japan, have been investigated from five perspectives: production, adsorption, physiochemical decomposition, bioaccumulation and biodegradation. In this study, temporal variability in microcystins in Lake Suwa were investigated over 25 years (1991~2015). In nature, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, during water treatment, the use of copper sulfate to remove algal cells causes extraction of a mess of microcystins. Cyanotoxins are removed by physical, chemical and biological methods, and the reduction of nutrients inflow is a basic method to prevent cyanobacterial bloom formation. However, this method is not effective for eutrophic lakes because nutrients are already present. The presence of a cyanotoxins can be a potential threat and therefore must be considered during water treatment. A complete understanding of the mechanism of cyanotoxins degradation in the ecosystem requires more intensive study, including a quantitative enumeration of cyanotoxin degrading microbes. This should be done in conjunction with an investigation of the microbial ecological mechanism of cyanobacteria degradation.

• 한국물환경학회지
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• 제21권4호
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• pp.337-346
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• 2005

An MSBR using a membrane for not only filtration but also aeration (MA-MSBR) was designed to reduce membrane fouling and to enhance water quality, and compared with an MSBR using a membrane for only filtration (BA-MSBR). COD removal efficiency of the MA-MSBR was similar to that of the BA-MSBR, but membrane performance of the MA-MSBR was better than that of the BA-MSBR. The MA-MSBR had more small particles in mixed liquor, so the specific cake resistance of flocs in the MA-MSBR was higher than that in the BA-MSBR. However, in the aerobic reaction step of the MA-MSBR, air went through membrane pores and out of the membrane surface, so cake layers on the membrane surface and a portion of organics adsorbed on membrane pores could be removed periodically. Therefore, cake resistance, $R_c$, and fouling resistance by adsorption and blocking, $R_f$, for the MA-MSBR increased more slowly than those for the BA-MSBR. Additionally, in order to compare the energy efficiency for two MSBRs, oxygen transfer efficiency and power to supply air into the reactor by a membrane module and a bubble stone diffuser were measured using deionized water. From these measurements, the transferred oxygen amount per unit energy was calculated, resulting that of MA-MSBR was slightly higher than that of BA-MSBR.

• 분석과학
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• 제23권5호
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• pp.429-436
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• 2010

본 연구는 다양한 종류의 음이온 교환수지와 활성탄으로 구성된 새로운 혼합 수지를 과염소산 이온의 제거에 응용할 경우, 각 흡착제들이 갖는 장점으로 인한 시너지 효과를 얻을 수 있는지 조사하였다. 특히 비군사화 과정에서 발생하는 고 농도의 과염소산 암모늄용액을 대상으로 하였는데, 혼합수지 중단일-기능기 음이온 교환수지와 활성탄의 조합에서 과염소산 이온의 흡착 효율이 향상되었다. 일반적으로는 분리된 흡착조를 이용하여 유기 오염물과 무기 음이온의 제거가 시행되는데 반해, 본 연구에서 시도한 혼합 수지를 사용할 경우 한 번에 동시 제거가 가능하여 제거과정에서 필요한 시간, 공간 및 비용을 감소시키는 효과를 얻을 수 있었다. 또한, 시료 중의 공존 음이온들에 대한 방해효과도 낮고 음이온 교환 수지에 비하여 특별한 단점이 없으며 실제시료에도 효과적으로 응용이 가능하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.171-171
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• 2009

The electrodes are usually made of a porous mixture of carbon-supported platinum and ionomers. $SnO_2$ particles provide as supports that have been used for DMFCs, and it have high catalytic activities toward methanol oxidation. The main advantage of $SnO_2$ supported electrodes is that it has strong chemical interactions with metallic components. The high activity to a synergistic bifunctional mechanism in which Pt provides the adsorption sites for CO, while oxygen adsorbs dissociative on $SnO_2$. The reaction between the adsorbed species occurs at the Pt/$SnO_2$ boundary. The morphological observations were characterized by FESEM and transmission electron microscopy (TEM). $SnO_2$ particles crystallinity was analyzed by the X-ray diffraction (XRD). The surface bonded state of the $SnO_2$ particles and electrode materials were observed by the X-ray photoelectron spectroscopy (XPS). The electric properties of the Pt/$SnO_2$ catalyst for methanol oxidation have been investigated by the cyclic voltametry (CV) in 0.1M $H_2SO_4$ and 0.1M MeOH aqueous solution. The peak current density of methanol oxidation was increased as the $SnO_2$ content in the anode catalysts increased. Pt/$SnO_2$ catalysts improve the removal of CO ads species formed on the platinum surface during methanol electro-oxidation.

• Applied Biological Chemistry
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• 제35권4호
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• pp.242-247
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• 1992

서울시 중량천 하수처리장의 활성오니로부터 총 20주의 pentachlorophenol(PCP) 내성균주들을 분리하여 B. sphaericus B-2와 B. schlegelii B-13를 포함한 Bacillus spp. 9주, Corynebacterium spp. 4주, Staphylococcus aureus S-1 1주, Aeromonas spp. A-19 1주, Arthrobacter LN-3 1주로 동정하였다. 이 균주들은 $200{\sim}300\;ppm$ PCP와 0.1% glucose가 포함된 mineral salt 배지에서 생육하였으며 PCP를 분해하는 종류 13주와 분해하지 못하고 흡착 혹은 흡수하는 종류 7주로 구분되었다. PCP 분해균주들은 대부분 배양 24시간후 생육이 최고에 도달하여 PCP를 약 $75{\sim}90%$ 분해하였으며 PCP 흡착 혹은 흡수하는 균주들은 흡착한 PCP를 배양 24시간 이후 또는 72시간 이후에 방출하였다. PCP 분해균주 B. sphaericus B-2, B. schlegelii B-13의 분해 산물을 TLC를 이용하여 검출한 결과 B. sphaericus B-2의 배양액에서 2-chlorophenol, B. schlegelii B-13에서는 2,4-dichlorophenol로 추정되는 물질과 4종의 분해산물로 보이는 물질들을 검출하였다.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.199-207
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• 2015

Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.461-465
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• 2005

Characteristics of biological $CO_2$ fixation by Chlorella sp. HA-1 were investigated in a semi-continuous and series reactor system using an internally illuminated photobioreactor to overcome shortcomings of physicochemical technologies such as adsorption and membrane separation. High $CO_2$ fixation rate was achieved in the semi-continuous reactor system, in which the dilution ratios of the culture medium were controlled. The average $CO_2$ fixation rate was maintained almost constantly when the dilution ratio increased by 0.1 increment from the initial value of 0.5. The total removal efficiency of $CO_2$ was enhanced by employing a series reactor system. The average $CO_2$ fixation rate increased until 4.013 g $CO_2\;day^{-1}$ in a series operation of four reactors, compared to 0.986 g $CO_2\;day^{-1}$ in a batch operation mode. The total $CO_2$ fixation rate was proportional to the number of reactors used in the series reactor system. In the series reactor system of semi-continuous operation, a large amount of $CO_2$ was removed continuously for 30 days. These results showed that the present reactor systems are efficient and economically feasible for a biological $CO_2$ fixation.

• 공업화학
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• 제25권4호
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• pp.346-351
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• 2014

인구증가와 산업화로 인한 물의 수요 급증에 따른 제3세대 수처리 기술로써 정전기적 흡 탈착 공정에 대한 연구가 진행되고 있다. 정전기적 흡 탈착 기술의 경우, 기존에 사용되는 수처리 방법들에 비해 에너지 소비량이 적으며, 재생시에 2차 오염이 발생하지 않아 차세대 수처리 기술로 주목 받고 있다. 정전기적 흡 탈착 기술에서 이온 제거를 위한 전극 물질로는 넓은 비표면적과 높은 전도도를 갖는 탄소 전극이 주로 사용된다. 현재 다양한 탄소 물질로 이루어진 전극에 대한 연구가 수행되고 있으며, 특히 비표면적, 기공 분포에 따른 흡 탈착 연구가 활발히 진행되고 있다. 본 총설에서는 다양한 탄소 물질 및 기공 분포에 따른 영향을 분석하고, 메조기공과 마이크로기공이 조화를 이루는 최적의 조건을 제시하고자 한다.

• 공업화학
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• 제24권6호
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• pp.645-649
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• 2013

본 연구에서는, 화력발전소 및 소각로 후단에서 발생되는 $NH_3$를 제어하기 위한 $W/TiO_2$ 촉매의 $NH_3$ 산화 반응 특성 연구를 수행하였다. 그 결과, $W/TiO_2$ 촉매의 텅스텐 최적함량은 10 wt% 임을 도출하였으며, 그 이상의 텅스텐을 담지 할 경우 비표면적의 감소로 인한 효율저하를 확인하였다. 또한, $NH_3$ 주입농도가 420 ppm 이상으로 주입될 경우 중 저온의 온도구간에서 효율저하를 나타냈으며, 수분이 존재할 경우 경쟁흡착으로 인한 효율저하가 발생하였고 산소농도가 증가할수록 $NH_3$의 전환율은 우수해지지만 $N_2$의 선택도가 낮아짐을 확인하였다.