• 대한환경공학회지
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• 제22권11호
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• pp.1969-1976
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• 2000

폐수의 복합독성과 다수의 미지 화합물의 영향을 평가하는 것은 많은 시간이 요구되고 분석상 어려움이 존재하는 경우가 많다. 그러므로 폐수중 독성을 나타내는 원인물질의 탐색과 처리효과를 평가하기 위한 방법을 확립하는 것이 절실히 요구된다. 본 연구에서는 질산화 저해제를 이용하여 혼합미생물중 질산화 미생물과 종속영양미생물을 구분하여 암모니아 저해도 실험을 수행하였으며, 이때 저해도는 dehydrogenase activity(DHA)를 이용한 미생물활성도의 차이로서 평가하였다. DHA에 의한 암모니아 저해 연구는 총 암모니아의 영향, 유리 암모니아의 영향, 질산화 미생물과 종속영양미생물의 암모니아 저해도에 대해 각각 평가되었다. 암모니아 독성은 총 암모니아 농도와 pH가 증가할수록 크게 나타나 유리 암모니아의 역할이 중요하게 작용함이 밝혀졌으나 미생물의 DHA는 총 암모니아와 유리 암모니아가 함께 고려되어야 정확히 평가될 수 있었다. 3.000mg/L 이상의 고농도의 암모니아에서는 질산화 미생물이 종속영양미생물 보다 심한 저해를 받는 것으로 나타났다.

• 수산해양교육연구
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• 제27권5호
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• pp.1229-1235
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• 2015

Juvenile banded catfish(Pseudobagurus fulvidraco, mean length $10.7{\pm}0.42cm$ and mean weight $15.0{\pm}0.23g$) were exposed to varies TAN(total ammonia) concentrations at pH levels of $6.12{\pm}0.51$, $7.00{\pm}0.26$ and $8.04{\pm}0.07$ for 96hrs to check the level of acute toxicity on biofloc technology aquaculture system(BFT). The result showed that cumulative mortalities for juvenile banded catfish at TAN levels 48.95, 55.96, 66.47, and 78.88 mg/L at pH $6.12{\pm}0.51$ were 0, 30, 30, and 50%, respectively. At pH $7.00{\pm}0.26$, its mortalities to TAN 5.20, 11.68, 15.31, and 18.31 mg/L were 0, 10, 20, and 70%, respectively and at pH $8.04{\pm}0.07$, the mortalities to TAN 0.96, 1.49, 2.13, and 3.62 mg/L were 10, 20, 40, and 100%, respectively. Its $96h-LC_{50}$ (median lethal concentration, $LC_{50}$) at pH $6.12{\pm}0.51$, $7.00{\pm}0.26$, and $8.04{\pm}0.07$ were 78.12, 15.87, and 2.21 mg/L for TAN, and 0.05, 0.10, and 0.14 mg/L for $NH_3$, respectively, and the acute toxicity for ammonia to juvenile banded catfish increased exponentially with increase of pH.

• 한국수산과학회지
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• 제47권6호
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• pp.840-846
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• 2014

This study investigated growth and hematological changes in parrotfish Oplegnathus fasciatus (~200 g/fish) reared under different total ammonia nitrogen (TAN) concentrations (0, 4, or 8 mg/L) for 6 weeks. Survival rates of parrotfish in all experimental groups did not significantly differ, as they were all ~100%. Although specific growth rate (SGR), weight gain, and daily feed intake in the high TAN concentration group (TAN8) were significantly lower than in the other two groups, there was no significant difference between the TAN4 group and the control group, (TAN0), indicating that parrotfish have a strong resistance to ammonia toxicity. As for temporal changes of the major blood components, cortisol increased as a result of stress caused by the high ammonia concentration in the TAN8 group. For this reason, the concentrations of energy sources such as glucose and total cholesterol were reduced. However, there was little difference among all experimental groups in concentrations of liver function glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), and nutrient factors, such as total protein and albumin.

• KSBB Journal
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• 제23권5호
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• pp.381-386
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• 2008

본 연구에서는 암모니아에 의해 손상된 사람의 간세포주 Hep G2 cell과 rat의 hepatocyte에 대하여 metronidazole이 간 세포 손상을 억제하는 효과가 있음을 밝혔다. Metronidazole은 암모니아에 의한 세포 생존율 감소, 배지내의 암모니아 수준 및 지질과산화 증가 및 항산화 효소 발현 감소 그리고 세포 내 DNA 손상과 세포사멸을 억제하였다. 따라서 metronidazole은 암모니아로부터 기인하는 세포손상을 감소시켜 간세포 기능을 보호함으로써 간 기능의 저하로 발생한 과암모니아혈증에 효과적인 치료제로서의 가능성을 시사한다.

• 한국토양비료학회지
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• 제43권6호
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• pp.975-977
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• 2010

Ammonium nitrogen is volatilized as ammonia at high pH soil. This study was conducted to observe an injury cause of egg plant grown in a high pH rockwool amended with ammonium phosphate. The etiolation symptom (yellowing) was appeared on veins of a leaf but not in healthy root when nutrient solution containing ammonium phosphate in addition to essential elements was applied in a top soil of which pH was 7.8. However, the same symptom did not appeared in the egg plant from the top soil in which the nutrition solution containing potassium phosphate instead of ammonium phosphate was applied. pHs were similar between these two different solutions. This revealed that the injury was caused by ammonia gas.

• 한국자동차공학회논문집
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• 제14권1호
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• pp.68-78
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• 2006

In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

• 한국어병학회지
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• 제35권1호
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• pp.65-75
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• 2022

Mirror carp, Cyprinus carpio nudus (weight 26.2±3.1 g, length 11.8±0.5 cm) were exposed to waterborne total ammonia nitrogen (TAN) at 0, 2, 4, 8, 16, 32, 64 and 128 mg TAN/L. The lethal concentration 50 (LC₅₀) of mirror carp, C. carpio nudus exposed to waterborne ammonia was 60.38 mg TAN/L. The red blood cell (RBC) count was significantly reduced by ammonia exposure, whereas there was no significant changes in the hemoglobin concentration and hematocrit value. In the plasma components, glucose, total protein, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly increased by ammonia exposure. The results of this study suggest that the ammonia exposure to C. carpio nudus affects the survival rates, hematological parameters and plasma components as toxicity.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.81-84
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• 2004

Control of Sediment is very important in prawn farm due to the eruption of toxic material such as W1ionized H2S, NH3 and NO2-. In this study, column test study, column with filter media such as activated carbon, zeolite, oyster shell and iron chloride to evaluate the reduction of toxicity from sediment ammonia-N(NH3) was effectively removed by Zeolite and oyster shell. It was indicated that ammonium ion(NH4+) was removed by ion exchange of zeolite. And the ammonia in the column of oyster shell was existed as the form of NH4+, which is not toxic for prawn because oyster shell was stably kept around pH 8. Therefore, some of ammonia(NH3) was reduced by oyster shell. Hydrogen sulfide and COD were effectively removed by adsorption of activated carbon and a partial removal of hydrogen sulfide was accomplished by Oyster shell. Phosphorous was removed by activated carbon, oyster shell and iron chloride. In prawn farm, the concentration of ammonia was increased with increase of pH by algae photosynthesis in the column of activated carbon, zeolite and iron chloride, but it was revealed that pH was stably kept in the column of oyster shell.

• 한국수산과학회지
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• 제55권5호
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• pp.697-704
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• 2022

This study was investigated to evaluate the level of acute TAN (total ammonia nitrogen) and NO₂^--N concentrations at pH levels of 6.0, 7.0 and 8.0 for 96 h in juvenile marbled eel Anguilla marmorata (total length 209.0±22.02 mm and body weight 13.0±5.01 g). The result of the present study showed that the survival rate of juvenile eel at TAN concentrations 0, 100, 200, 300, 400, and 500 ppm at pH 6.0, pH 7.0, and pH 8.0 were 100, 100, 96.7, 74.4, 31.1, and 0%; 100, 82.2, 61.1, 36.7, 0, and 0%; and 98.9, 55.6, 8.9, 0, 0, and 0%, respectively. In addition, the survival rate of juvenile eel at NO₂^--N concentrations 0, 100, 200, 300, 400, and 500 ppm at pH 6.0, pH 7.0, and pH 8.0 were 100, 43.3, 21.7, 0, 0, and 0%; 100, 76.7, 65.0, 43.3, 21.7, and 13.3%; and 100, 100, 100, 88.3, 78.3; and 58.3% respectively. The 96h-LC₅₀ at pH 6.0, 7.0, and 8.0 were 332, 235, and 167 mg/L for TAN, and 188, 296, and 711 mg/L for NO₂^--N, respectively. The acute toxicity of TAN to juvenile eel increased exponentially with increase in pH, whereas the acute toxicity of NO₂^--N to juvenile ell increased with low levels of pH and lengthening of exposure time to NO₂^--N.

• 한국어병학회지
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• 제9권2호
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• pp.147-155
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• 1996

수온과 pH가 높은 조건에서 뱀장어에 미치는 암모니아 급성독성에 대하여 육안적인 면과 병리조직학적 변성을 관찰하였다. 육안 관찰 결과, 암모니아 무첨가구(0 mg/$\ell$)에서는 pH 8.5이상에서 아가미의 암갈색화가 진행되었고 암모니아 20 mg/$\ell$ 이상의 농도에서는 pH 7.5에서도 위와 같은 증상이 나타났다. pH 9.0에서는 암모니아 10 mg/$\ell$이상의 농도에서 1시간 이내에 전부 폐사했다. 아가미에 대한 조직학적 관찰 결과는 암모니아 무첨가구의 pH 7.5에서만 정상 조직이 관찰되었고 수온과 pH의 상승, 암모니아 농도의 증가 및 노출시간의 경과에 따라 조직의 변성이 심해지는 경향을 보였다. 암모니아 무첨가구의 pH 8.0, 8.5에서도 2차새변의 부종과 만곡증상이 보였고 pH 9.0에서는 2차새변 상피의 박리증상이 나타난 것으로 보아 높은 pH 조건만으로도 병변을 일으키는 요인이 될 수 있는 것으로 사료된다. 조직학적 변성의 초기에는 2차새변의 부종과 만곡증상이 보이다가 상피세포의 박리와 괴사로 진행 되었으며, 특히 2차새변상피의 박리증상은 육안적으로 관찰되는 아가미의 암갈색으로 변색시점과 비슷한 시기에 관찰되었다. 암모니아 20 mg/$\ell$이상에서는 pH 8.5, 수온 $27^{\circ}C$ 조건에서 2차새변상피의 괴사가 일어났고, 수온 $32^{\circ}C$에서는 노출시간이 경과하면서 폐사체가 생겼다.