• 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.

• Resources Recycling
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• v.32 no.6
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• pp.45-53
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• 2023

This study discussed the trend and future strategy of adsorption technology R&D to effectively recover ammonia emitted from the livestock fields. A proper ammonia adsorbent should incorporate acidic or hydrogen bonding functional groups on the surface, as well as a high specific surface area and a good surface structure appropriate for ammonia adsorption. Activated carbon and minerals such as zeolite have widely been used as ammonia adsorbents, but their adsorption effects are generally low, so any improvement through surface modification should be necessary. For example, incorporation of metal chloride included in a porous adsorbent can promote ammonia adsorption effectiveness. Recently, new types of adsorbents such as MOFs (Metal-Organic Frameworks) and POPs (Porous Organic Polymers) have been developed and utilized. They have shown very high ammonia adsorption capacity because of adjustable and high specific surface area and porosity. In addition, Prussian Blue exhibited high ammonia adsorption and desorption performance and selectivity. This looks relatively advantageous in relation to the recovery of ammonia from livestock waste discharge. In the future, further research should be made to evaluate ammonia adsorption/desorption efficiency and purity using various adsorbents under conditions suitable for livestock sites. Also, effective pre- and/or post-treatment processes should be integrated to maximize ammonia recovery.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.11a
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• pp.77-79
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• 2001

본 연구에서는 전기분해에 의한 양식장 배출수중의 유기물질 및 암모니아를 전류밀도, 전극간격에 따른 제거 특성을 살펴보았다. 전극간격 및 전류밀도에 따른 제거효율은 전극간격이 가까울수록, 전류밀도가 클수록 제거효율은 증가하였다 유기물질은 107.5A/$m^2$의 전류밀도에서 반응기 체류시간 8분동안 98.5%, 암모니아는 전류밀도를 107.15A/$m^2$로 유지하고, 간격을 변화시키면서 반응기 체류시간 120sec동안 암모니아의 제거율을 보면 92.6%의 제거효율을 나타내었다.

• The Microorganisms and Industry
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• v.14 no.3
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• pp.16-20
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• 1988

암모니아를 아질산또는 질산으로 산화시키는 과정인 질화작용(nitrification)은 암모니아와 함께 또 하나의 식물및 미생물에 대한 질소원인 질산의 농도를 증사시켜 생물의 생장을 뒷받침하기도 하나(Fenchel and Blackburn, 1979) 생물체의 질소원에 있어서 세가지의 불이익을 초래하기도 한다. 질산은 암모니아와는 달리 토양이나 저질토(sediment)의 cation exchange site에 흡착되지 않으므로 쉽게 손실된다(Greenland, 1958). 또 무산소상태에서는 탈질화과정 (denitrification)에 의하여 기체질소로 환원되어 생태계내에서 사라진다 (Broadbent and Clark, 1965). 끝으로 질산태의 질소가 생물체내의 질소의 주 형태인 아미노산의 질소로 되기 위해서는 암모니아로 환원되어야 하므로 질산의 동화는 상대적으로 많은 에너지를 필요로한다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.70-71
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• 2002

암모니아 가스는 일반환경에서 뿐만 아니라 첨단 산업인 반도체 제조공정에서도 가장 주목하여 관리하여야 할 대상이다. 반도체 공정에서 암모니아 가스는 T-Topping, 광학 현미경의 헤이즈 현상 등을 일으키는 원인으로써 꾸준한 농도 관리가 요구되고 있다. 또한 관리 기준 농도가 점점 강화되면서 일부 공정에서는 sub ppbv까지 신뢰성 있는 측정치 요구되고 있다. 현재 클린룸에서의 암모니아 농도 관리는 일부 자동화 기기를 사용하고 있으나, 대부분의 경우 임핀저 샘플링을 이용한 불연속적인 농도 관리가 이루어지고 있다. (중략)

• Journal of Aquaculture
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• v.18 no.4
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• pp.280-286
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• 2005

Experiments were conducted to examine the differences in ammonia removal rates with the different filter media between sand and zeolite, the expanding rates between $50\%$ and $100\%$, the water temperatures between $15^{\circ}C$ and $25^{\circ}C$, and the ammonia loading rates between 2 mg/L and 5 mg/L in the seawater fluidized bed filters system (FBF). The 2.1 m high FBF (8.3 cm diameter) consisted of the clear acrylic for the upper half and a PVC pipe for the lower half, Sand and zeolite were used as the filter media in sizes of 0.5$\pm$0.1mm. Each biofilter contained 5.4 L of media. The ammonia removal rates of the biofilter were higher at the $25^{\circ}C$ water temperature than those of the biofilter at $15^{\circ}C$ water temperature, and higher at the $50\%$ expanding rate of filter media than those of the biofilter at $100\%$ expanding rate of filter media. Also, the ammonia removal rates of FBF were higher at 5 mg/L ammonia concentration than those of FBF at 2 mg/L ammonia concentration in rearing water. With these better conditions the ammonia removal rates of FBF per day are practically acceptable and ranged ken 80.6 to $210.6g/m^3$.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.583-590
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• 2011

The effect of the physical parameters in the reactor (aeration depth, bubble size, and surface area) and the alkalinity of the solution on the ammonia stripping by bubbling were evaluated. When an airflow of 30 L/min was bubbled below the solution surface in the range 6-53 cm, the ammonia removal rate were observed to be the same regardless of the bubbling depths. At pH 10.0 and a temperature of $30^{\circ}C$, the average rate constant and the standard deviation were $0.178h^{-1}$ and 0.004. No appreciable changes in the ammonia removal rate were also observed with varying the bubble size and the air-contacting surface area. Alkalinity of the solution was found to affect the ammonia removal rate indirectly. This is expected because the pH of the solution would vary with dissolution of gaseous $CO_2$ by air bubbling. The real wastewaters from landfill site and domestic wastewater treatment plant were tested. In the case of domestic wastewater (pH = 7.1, alkalinity = 75 mg/L), the ammonia removal rate was poor even with the control of pH to 9.3. The raw landfill leachate (pH = 8.0, alkalinity = 6,525 mg/L), however, showed the appreciable removal rate with increasing pH during aeration. When the initial pH of the leachate was adjusted 9.4, the removal rate was significantly increased without changing the pH during aeration.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.9-15
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• 2005

In order to know the electrochemical decomposition characteristics of ammonia to nitrogen, this work has studied several experimental variables on the electrolytic ammonia decomposition. The effects of pH and chloride ion at $IrO_2$, $RuO_2$, and Pt anodes on the electrolytic decomposition of ammonia were compared, and the existence of membrane equipped in the cell and the changes of the current density, the initial ammonia concentration and so on were investigated on the decomposition. The performances of the electrode were totally in order of $RuO_2{\approx}IrO_2>Pt$ in the both of acid and alkali conditions, and the ammonia decomposition was the highest at a current density of $80mA/cm^2$, over which it decreased, because the adsorption of ammonia on the electrode surface was hindered due to the evolution of oxygen. The ammonia decomposition increased with the concentration of chloride ion in the solution. However, the increase became much dull over 10 g/l of chloride ion. The $RuO_2$ electrode among the tested electrodes generated the most OH radicals which could oxidized the ammonium ion at pH 7.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.215-222
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• 1988

The effect of ammonia and glutamine on nitrogenase activity of Rhodopseudomonas sphaeroides was examined. The nitrogenase activity of this strain was inhibited by ammonia and glutamine. When ammonia and glutamine were exhausted, nitrogenase activity promptly resumed at its original rate. Methionine sulfoximine (MSX), irreversible glutamine synthetase (GS) inhibitor, is a structural analogue of glutamate. MSX was used in order to know whether the nitrogenase activity was inhibited by ammonia and glutamine directly or not. The ability of MSX to prevent nitrogenase switch-off by ammonia was found to be dependent upon the phase of culture. When the cells were sampled after 12 hour culture, $500{\mu}M$ MSX would not prevent the nitrogenase switch-off by ammonia. Twenty one percents of GS actibity was inhibited by $500{\mu}M$ of MSX and concentration of released ammonia decreased. But nitrogenase activiy was still inhibited by ammonia. However, nitrogenase switch-off after 20 hours would be prevented by $100{\mu}M$ of MSX. On the other hand, GS activity was ingibited completely by $100{\mu}M$ MSX and concentration of released ammonia somewhat increased. But nitrogenase activity was not inhibited. The data indicated that the inhibition of in vivo nitrogenase actibity of Rp. sphaeroides by ammonia seemed to be mediated by products of ammonia assimilation rather than by ammonia itself.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.49-55
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• 2022

According to reinforce environmental regulations, coal power plants have used selective catalytic reduction using ammonia as a reducing agent to reduce the amount of nitrogen oxide generation. The purpose of the present study was to derive a mixing device for effectively mixing dilute air and ammonia in the ammonia mixing pipe by performing computational fluid dynamic analysis. The mixing effect was compared by analysing the %RMS of ammonia concentration at the down stream cross section in the mixing pipe and the 16 outlets based on the case 1-1 shape, which is an existing mixing pipe without a mixing device. The mixing device was performed by changing the positions of a square plate on the downstream side of the ammonia supply pipe and an arc-shaped plate on the wall of the mixing pipe. In the case of the existing geometry(Case 1-1), the %RMS of ammonia concentration at the 16 outlets was 29.50%. The shape of the mixing device for Case 3-2 had a square plate on the downstream side of the ammonia supply pipe and an arc plate was installed adjacent to it. The %RMS of ammonia concentration for Case 3-2 was 2.08% at 16 outlets and it could be seen that the shape of Case 3-2 was the most effective mixing shape for ammonia mixing.