• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.43-44
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• 2001

산업의 발달과 함께 화석연료의 소비가 증가하면서 산성강하물(Acid precipitation)에 대한 관심이 증가하여 왔다. 산성강하물은 주로 화석연료의 연소를 통해 대기로 배출된 질소와 황 산화물들로, 산화ㆍ환원, 산ㆍ염기 중화반응 등 다양한 변환과정을 거쳐 비나 눈과 같은 습성과정이나 가스나 입자상 물질과 같은 건성과정을 통해 다시 토양과 호수 등에 침적되어 이들을 산성화시키는 원인이 된다. 따라서 산성강하물에 대한 이해를 위해서는 강수의 화학조성과 아울러 가스와 입자상으로 존재하는 질소와 황화합물에 대한 관측이 필수적이다. (중략)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.760-766
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• 1998

This study was carried out far isolation and characterization of ammonia oxidizing bacteria (AOB) from aquacultural place and sludges of waste water collected in Pusan. One autotrophic AOB, Nitrosomonas sp. and 8 heterotrophic AOB (2 strains of Bacillus sp., 2 strains of Acinetobacter sp., Xanthomonas sp., Alcaligenes sp., Pseudomonas sp., Sphingobacterium sp.) were isolated. and identified. Variation of total nmmonia nitrogen (TAN) and $NO_2-N$ in mineral salt media containing 10mg/ $\ell$ of NHCl for 15 days in differents 9 strains was measured in order to examine the ablitity of ammonia oxidation. TAN was started to reduce after 4 days incubation and ca. 2 mg/$\ell$ of TAN was decreased after 15 days incubation by Nitrosomonas sp., At that time, $NO_2-N$ was produced to 0.023$\~$0.036 mg/$\ell$. Heterotrophic AOB showed the low ability of ammonia oxidation, 0.02$\~$0,04 mg/$\ell$ of TAN was decreased and $NO_2-N$ was produced to 0.01$\~$0.51 mg/$\ell$ after 15 days. When each strain of 8 heterotrophs was incubated in mimeral salt media containing 10 mg/$\ell$ $NH_4Cl$ and 50 mg/$\ell$ glucose, and 50 mg/$\ell$ $NH_4Cl$ and 5 g/$\ell$ glucose, the diminution of TAN was 1.12$\~$3.38 mg/$\ell$ and 1$\~$20 mg/$\ell$, respectively.

• Korean Journal of Materials Research
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• v.8 no.10
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• pp.945-949
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• 1998

Ta(OC2H5)5와 NH3를 이용하여 Cycle-CVD법으로 산화탄탈륨 막을 증착하였다. Cycle-CVD법에서는 Ta(OC2H5)5와 NH3사이에 불활성 기체를 주입한다. 하나의 cycle은 Ta(OC2H5)5주입, Ar주입, NH3 주입, Ar 주입의 네 단계로 이루어진다. Cycle-CVD법으로 산화탄탈륨 막을 증착할 때, 온도 $250-280^{\circ}C$에서 박막의 증착 기구는 원자층 증착(Atomic Layer Deposition:ALD)이었다. $265^{\circ}C$에서 Ta(OC2H5)5:Ar:NH3:Ar:NH3:Ar의 한 cycle에서 각 단계의 주입 시간을 1-60초:5초:5초:5초로 Ta(OC2H5)5 주입 시간을 변화시키면서 산화탄탈륨 막을 Cycle-CVD법으로 증착하였다. Ta(OC2H5)5주입시간이 증가하여도 cycle 당 두께가 $1.5\AA$/cycle로 일정하였다. $265^{\circ}C$에서 증착된 박막의 누설 전류는 2MV/cm에서 2x10-2A/$\textrm{cm}^2$이었고 열처리후의 산화탄탈륨 막의 누설 전류값은 $10-4A\textrm{cm}^2$ 이하고 감소하였다. 증착한 산화탄탈륨 막의 성분을 Auger 전자 분광법으로 분석하였다. 2$65^{\circ}C$에서 증착한 막의 성분은 탄탈륨 33at%, 산소 50at%, 탄소 5at%, 질소 12at% 이었으며 90$0^{\circ}C$, O2300torr에서 10분 동안 열처리한 박막은 탄탈륨 33at%, 산소 60wt%, 탄소 4at%, 질소 3at%이었다. 박막의 열처리 온도가 높을수록 불순물인 탄소와 질소의 박막 내 잔류량이 감소하였다. 열처리 후의 박막은 O/Ta 화학정량비가 증가하였으며 Ta의 4f7/5와 4f 5/2의 결합 강도가 열처리 전 박막보다 증가하였다. 열처리 후 누설 전류가 감소하는 것은 불순물 감소와 화학정량비 개선 및 Ta-O 결합 강도의증가에 의한 것으로 생각된다.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.185-192
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• 2011

BNR process is an effective method to remove high strength nitrogen included in wastewater and piggery wastewater. There have been many former studies about the induction of nitritation which have many advantages than full nitrification and the impacting factors on nitritation. Especially, it is reported that organic matter has a relation with nitritation. In this study, laboratory sacle reactor was operated using effluent of anaerobic digester, piggery wastewater and anaerobic digester effluent of piggery wastewater. After analyzing the operating results, the impact of organic matter on nitritation was analyzed by classified COD fractions. It was showed that nitritation is affected by organic matter especially by Ss. In conclusion, organic matter should be managed not just as a single gross parameter but in a classified form.

• Journal of Life Science
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• v.13 no.1
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• pp.47-53
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• 2003

The purpose of this study is to improve the system for biological nitrogen oxidizing process in sewage and wastewater. A bacterium having high abilities to oxidize of nitrogen was one of the possessed on Lab. The strain was identified to Bacillus sp. A8-8, based on the physiological and biochemical properties. And the strain has ability degradation crude oil. In comparison with oxidizing rates with changing initial pH and temperature, the strain Bacillus sp. A8-8 was nitrogen oxidizing ability and growth rate on the various of pH, temperature. oxidizing rates of the strain in sewage and wastewater were about 48% and 62%, respectively. The nitrogen oxidizing rate was increased in proportion to the initial concentration of glucose. The microorganism, Bacillus sp. A8-8, immobilized in ceramic carrier were evaluated for the oxidation of ammonia in culture media.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.789-798
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• 2011

We carry out an experimental investigation to analyze the basic performance of NO(nitric oxide) storage in a lean phase and also analyze the NO reduction achieved by the spraying of reducing agents in the rich phase of the exhaust gas in an LNT(Lean NOx Trap). This is an after-treatment system used to reduce the NOx emissions from a diesel engine. If the stored NO is reduced, we measure the outlet concentration downstream of the LNT. The test LNT material used in the experiments is commercial LNT. After being canned into stainless-steel(SUS304), it was built in a micro bench-flow reactor. Compositions of feed gases, three heated and three no heated gases were sprayed upstream of the LNT to analyze the characteristics. We use various temperatures and space velocities as response variables.

• Bulletin of Korea Environmental Preservation Association
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• v.11 no.3
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• pp.5-6
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• 1989

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.73-80
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• 2010

Two nitrite oxidizing bacteria, NOB1 and NOB2, were isolated from anaerobic digester liquer of food wastewater and analyzed for their growth characteristics and the ability to oxidize nitrite under different temperature, pH, and DO( dissolved oxygen) concentrations. Both of the isolated strains have shown the best growth at pH 7.0 and at $35^{\circ}C$, and also shown higher growth rate with the increasing dissolved oxygen concentrations. As the factors to restrict the growth of these strains, parameters such as pH and DO were found to be effective ones, by increasing (up to 9.0) or decreasing pH (up to 5.0), or lowing DO below 1.0 ppm. Especially, the ability to oxidize nitrite in both strains was about 50% lower in below 1.0 ppm of DO than above of 1.0 ppm. NOB2 was found to be two times greater in both the growth rate and the nitrite-oxidizing ability than NOB1.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.700-704
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• 2008

Nitrite and free ammonia have been known as substrate inhibitors in anaerobic ammonium oxidation. To reduce inhibitory effect of these substrates, the NH$_3$-N/NO$_2$-N ratio in the influent could be properly controlled in anaerobic ammonium oxidation process. Five kinds of NH$_3$-N/NO$_2$-N ratio were assayed in batch to find optimum NH$_3$-N/NO$_2$-N ratio, curtailing substrate inhibition. As the results of batch test, the highest T-N removal efficiency of 88% was obtained at 1.00 : 1.30 of NH$_3$-N/NO$_2$-N ratio. In addition, rate constants for ammonium and nitrite in zero-order kinetics were found to be the highest values as 7.66 mg/L$\cdot$hr and 11.89 mg/L$\cdot$hr at 1.00 : 1.30 ratio, respectively. However, as for the specific anammox activity, the ratio of NH$_3$-N/NO$_2$-N ratio was recommended as 1 : 1.15 which can maintain the highest SAA during continuous operation and preclude the accumulation of nitrite in the reactor.

• 수도
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• s.69
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• pp.23-46
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• 1994

하수처리장으로부터의 질소제거는 과거 3차 처리의 개념을 토대로 시설비가 고가로 소요되었으나 현재는 2차 처리시에 탄소제거와 함께 질소를 제거하는 개념으로 바뀌어지고 있다. 또한 질소제거는 탄소제거만에 의한 수질보호 차원에서 암모니아 독성을 제거하며 질소산화에 의한 추가 산소소모를 감소시키는 효과를 기대할 수 있다. 2차 처리시설에 의한 질소제거는 약 6%의 시설비와 연간 유지관리비의 증가에 불과하다. 질소제거는 하천이나 호소수의 수질개선뿐만 아니라 독성제거와 산소공급 내지 산소결핍 가능성을 저하시키며 하수처리장의 수질을 향상시킨다. 따라서 앞으로 질소제거는 모든 하수처리장의 2차 처리시설에 적용이 되리라는 것이 국제적인 추세이다. 하수처리장이 계속해서 신설되고 있는 우리나라로서는 이러한 개념을 되도록 빨리 받아들여 뒤늦게 질소제거를 수행함에 따르는 추가 비용의 낭비를 최소화 시키는 것이 현명하리라 생각된다.