• Title, Summary, Keyword: NH3(암모니아)

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A Study on the Uniform Mixing of Ammonia-Air with the Change of Ammonia Supply Device Shape in a De-NOx System (탈질설비에서 암모니아 혼합기의 형상에 따른 암모니아-공기 균일 혼합에 관한 연구)

  • Ha, Ji Soo
    • Journal of the Korean Institute of Gas
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    • v.23 no.3
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    • pp.20-26
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    • 2019
  • Selective catalytic reduction(SCR) method is widely used among various methods for reducing nitrogen oxides in combustion devices of coal power plant. In the present study, the computational fluid dynamic analysis was accomplished to derive the optimal shape of ammonia-dilution air mixing device in a ammonia injection grid. The distribution characteristics of flow and $NH_3$ concentration had been elucidated for the reference shape of ammonia mixing device(Case 1). In the mixing device of Case 1, it could be seen that $NH_3$ distribution was shifted to the wall opposite to the inlet of the ammonia injection pipe. For the improvement of $NH_3$ distribution, the case(Case 2) with closing one upper injection hole and 4 side injection holes, the case(Case 3) with installing horizontal plate at the upper of ammonia injection pipe, the case(Case 4) with installing horizontal plate and horizontal arc plate at he upper of ammonia injection pipe were investigated by analyzing flow and $NH_3$ concentration distributions. From the present study, it was found that the % RMS of $NH_3$ for Case 4 was 4.92%, which was the smallest value among four cases, and the range of $R_{NH3}$ also has the optimally uniform distribution, -10.82~8.34%.

[ $NH_3$ ] Pulse Plasma Treatment for Atomic Layer Deposition of W-N Diffusion Barrier (암모니아 펄스 플라즈마를 이용한 원자층 증착된 질화텅스텐 확산방지막 특성)

  • Lee, Chang-Woo
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.4
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    • pp.29-35
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    • 2004
  • We have deposited the W-N diffusion barrier on Si substrate with $NH_3$ pulse plasma enhanced atomic layer deposition (PPALD) method by using $WF_6$ and $NH_3$ gases. The $WF_6$ gas reacts with Si that the surface corrosion occurs severely, but the $NH_3$ gas incorporated with pulse plasma and $WF_6$ gas are easily deposited W-N thin film without Si surface corrosion. Because the $NH_3$ with pulse plasma can be active species dissociated and chemisorbed on Si. Thus the Si surface are covered and saturated with nitrogen, which are able to deposit the W-N thin film. We also examine the deposition mechanism and the effect of $NH_3$ pulse plasma treatment.

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Effects of Ammina on Survival and Growth of the Flounder Larva, Paralichthys olivaceus (넙치, Paralichthys olivaceus 자어의 생존과 성장에 미치는 암모니아의 영향)

  • KIM Hyung-Soo;KIM Heung-Yun;CHIN Pyung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.3
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    • pp.488-495
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    • 1997
  • The effects of ammonia on survival and growth of the flounder larva, Paralichthys olivaceus, were examined by a static renewal bioassay method. The $96\;hr-LC_{50}$ with the developmental stages during the period from 1day to 23 day-old larvae ranged 0.273 to 1.023 mg $NH_3/\ell$. Tolerance of the larvae to ammonia toxicity was much sensitive at the early larval stage, and increased with the growth of the larvae. Threshold $96hr-LC_{50}$ in 1, 3 and S day-old larvae after hatching were 0.293, 0.248 and 0.379 mg $NH_3/\ell$, respectively. Survival rate and growth in body weight and body weight of the larva were reduced with increase of ammonia concentration in the range of 0.055 and 0.341 mg $NH_3/\ell$. The no-observable-effect concentration (NOEC) and lowest-observable- effect concentration (LOEC) of the flounder larve were 0.102 and 0.174 mg $NH_3/\ell$ for body length, and 0.151 and 0.198 mg $NH_3/\ell$ for body weight, respectively. Chronic value (ChV), which is the geometric mean of the NOEC and $NH_3/\ell$ to body length of the larvae were 0.124 mg $NH_3/\ell$. The coefficient of variation (CV) for body length was higher at high concentration than at low concentration.

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Effect of Precipitation on Operation Range of the CO2 Capture Process using Ammonia Water Absorbent (암모니아수 흡수제를 이용한 이산화탄소 제거 공정에서 침전생성이 조업영역에 미치는 영향)

  • You, Jong Kyun;Park, Ho Seok;Hong, Won Hi;Park, Jongkee;Kim, Jong-Nam
    • Korean Chemical Engineering Research
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    • v.45 no.3
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    • pp.258-263
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    • 2007
  • Ammonia water was investigated as a new absorbent of the chemical absorption process for the removal of $CO_2$ in flue gas. The suitable range of ammonia water concentration and $CO_2$ loading ($mol\;CO_2/mol\;NH_3$) were decided in the point of view of $CO_2$ absorption capacity and $NH_4HCO_3$ precipitation. The absorption capacity of $CO_2$ and the precipitation of $NH_4HCO_3$ in liquid phase were calculated by the Pitzer model for electrolyte solution. The $CO_2$ absorption capacity of the ammonia water over $5\;molNH_3/kgH_2O$ was higher than that of conventional amine absorbent. The $CO_2$ loadings where precipitation occurred were decided at various absorbent concentrations. Theses values were higher than 0.5 in the concentration range of $5-14\;molNH_3/kgH_2O$ at 293, 313 K. The absorber for the removal of $CO_2$ in flue gas could be operated without $NH_4HCO_3$ precipitation by using high concentration of ammonia water below these $CO_2$ loading values. The optimum temperature of the ammonia water absorbent for removal of $CO_2$ in flue gas was 297-312 K depending on the concentration of ammonia water.

Selective Catalytic Oxidation of Ammonia over Noble Catalysts Supported on Acidic Fe-ZSM5 Supports (산성 Fe-ZSM5 담체에 담지된 귀금속 촉매를 활용한 암모니아의 선택적 산화반응)

  • Kim, Min-Sung;Lee, Dae-Won;Lee, Kwan-Young
    • Clean Technology
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    • v.18 no.1
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    • pp.89-94
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    • 2012
  • In this study, we investigated the activity of Pd and Pt supported on acidic Fe-ZSM5 supports for selective catalytic oxidation of ammonia ($NH_3$-SCO). Among the catalysts, Pt/Fe-ZSM5 catalyst exhibited superior $NH_3$-SCO activity to Pd/Fe-ZSM5 catalyst. We also tested Pt/Fe-ZSM5 catalysts with different Fe loading using ion-exchange method to prepare Fe-ZSM5 supports, which resulted in the increased catalytic performance with smaller Fe content: $NH_3$ was oxidized completely at low temperature ($250^{\circ}C$). The physicochemical properties of Fe-ZSM5 were investigated to figure out the relationship between the characteristics of the catalysts and the catalytic activity on $NH_3$-SCO by Inductively coupled plasma-atomic emissions spectrometer (ICP-AES), $N_2$ sorption, X-ray diffraction (XRD), temperature programmed desorption of $NH_3$ ($NH_3$-TPD) technique.

Effects of Ammonia Loading on Nitrification and Nitrite Build-up in an Activated Carbon Fluidized Bed Biofilm Reactor (암모니아 부하가 활성탄 유동상에서의 질산화 및 아질산 축적에 미치는 영향)

  • Choi, In-Cheol;Park, Soo-Young;Lee, Kwan-Yong;Bae, Jae-Ho;Cho, Kwang-Myeung
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.1
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    • pp.53-60
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    • 2000
  • The effects of ammonia loading on nitrification, especially on nitrite build-up, in an activated carbon fluidized bed reactor were investigated by increasing the ammonia loading rate stepwise from 0.1 to $7.5kg\;NH_3-N/m^3{\cdot}day$. Although effluent nitrite concentration and nitrification efficiency fluctuated at the loading rates above $1.8kg\;NH_3-N/m^3{\cdot}day$, an average nitrification efficiency of 90% was achieved. Nitrite build-up began at an ammonia loading rate of $l.8kg\;NH_3-N/m^3{\cdot}day$, at which the free ammonia concentration was estimated to be above 1 mg/L. During the nitrite build-up, the ratio of influent $NH_3-N$ concentration to the DO concentration of the reactor liquor and the ratio of effluent $NH_3-N$ concentration to the DO concentration of the reactor liquor was measured to be above 100 and 2, respectively. Considering the advantages of nitritation/denitrification, a fluidized bed reactor could be an effective means for biological nitrification of wastewaters with high ammonia concentration.

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Ammonia Volatilization from Coated Urea in Paddy Soil of Transplanting Rice Culture (벼 이앙재배에서 피복요소 시용에 따른 암모니아 휘산)

  • Lee, Dong-Wook;Park, Ki-Do;Park, Chang-Young;Kang, Ui-Gum;Son, Il-Soo;Yun, Eul-Soo;Park, Sung-Tae;Lee, Suk-Soon
    • Korean Journal of Soil Science and Fertilizer
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    • v.38 no.6
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    • pp.321-327
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    • 2005
  • Ammonia ($NH_3$) volatilization was measured from latex coated urea (LCU) and normal urea treated rice paddy under transplanting rice culture in Milyang in 2002 and 2003. The $NH_3$ volatilization from incubation experiment was significantly related with ammonium-N ($NH_4-N$) concentration and pH in the surface water. The correlation coefficients of $NH_3$ volatilization compared to the $NH_4-N$ and pH in surface water were significantly higher in urea than LCU. The $NH_3$ volatilization from both urea and LCU treatments was not increased in surface water of pH less than 8.0, while $NH_3$ volatilization increased significantly in the surface water of pH over 8.0. The results in the field experiment indicated that $NH_3$ volatilization after top-dressing of urea increased rapidly with increasing $NH_4-N$ concentration in soil and floodwater, and highest from 7 to 10 days after top-dressing. The amount of $NH_3$ volatilized from urea treatment was in the range of $4.9-8.4kg\;N\;ha^{-1}$. The variations of $NH_3$ volatilization in 2002 and 2003 were caused by changed N dynamics due to the different weather conditions such as rainfall and temperature. The amount of $NH_3$ volatilized from LCU treatment was significantly reduced compared to that of urea. The reason for the reduced $NH_3$ volatilization in LCU treatment would be due to the lower concentration of $NH_4-N$ in floodwater. The amount of $NH_3$ volatilized from LCU treated rice paddy was in the range of $1.2-1.8kg\;N\;ha^{-1}$, and the loss of N by ammonia volatilization was 2.0-2.3%. Loss of N by $NH_3$ volatilization with LCU treatment was reduced by 75-79% comparing to urea treatment.

Biological Study on the Increment of Survival Rate during Early Life Cycle in th Rockfish, Sebastes schlegeli (Telostei: Scorpaenidae) - I. Effects of Ammonia on Survival and Growth of the Larvae and Juveniles Stage (조피볼락, Sebastes schlegeli의 초기생활사 동안 생존율 향상을 위한 생물학적 연구 - I. 자어의 생존과 성장에 미치는 암모니아의 영향)

  • Chin, Pyung;Shin, Yun-Kyung;Kim, Hak-Gyoon;Lee, Jeong-Sick;Kim, Hyung-Soo
    • Korean Journal of Ichthyology
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    • v.10 no.1
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    • pp.98-105
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    • 1998
  • The effect of ammonia on survival and growth of the larval rockfish, Sebastes schlegeli was examined by a static renewal bioassay method. The tolerance of larvae to ammonia toxicity was more sensitive at the early larvae, but increased with the development of larvae. In 14 day-old-larvae after parturition, the mortality with treatment of each concentration of ammonia was 5% at control group and 0.0112 $NH_3$mg/l, whereas it was increased up to 27.5% at exposure group of 0.1230 $NH_3$mg/l with higher concentration. Regression equation between ammonium concentration(X) and mortality(Y) was followed; Y=0.516+3.482 X($r^2=0.4737$, P<0.01). The NOEC(no-observable-effect concentration) and LOEC (lowest-observable-effect concentration) to mortality compared to control group were 0.100 $NH_3mg/l$ and 0.1230 $NH_3$mg/l, respectively and chronic value(ChV) which is the geometric mean of the NOEC and LOEC was 0.1110 $NH_3$mg/l. Body length after 7-days exposure in control group, 0.0112 $NH_3$mg/l and 0.1230 $NH_3$mg/l were 7.8325mm, 7.700mm and 7.05mm, respectively. The NOEC, LOEC and chronic value(ChV) were 0.0335 $NH_3$mg/l, 0.0558 $NH_3$mg/l and 0.0432 $NH_3$mg/l, respectively.

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A comparative study on ammonia emission inventory in livestock manure compost application through a foreign case study (국내외 가축분뇨 퇴액비 이용 분야 암모니아 배출량 인벤토리 비교 연구)

  • Kim, Min-Suk;Koo, Namin;Kim, Jeong-Gyu
    • Korean Journal of Environmental Biology
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    • v.38 no.1
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    • pp.71-81
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    • 2020
  • In Korea, more than 70% of the ammonia(NH3) released into the atmosphere is known to originate from livestock manure. The total emission (kg year-1) is calculated by multiplying the emission factor (kg head-1 yr-1) and the activity data (head). To improve the accuracy and reliability of the NH3 emission estimation process, an accurate account of livestock manure production, calculation of NH3 conversion and generation during the composting and liquefaction of manure, estimation of NH3 generation in the storage and transportation of manure and compost, and a comparative study of NH3 emission during the soil spreading process must be performed. Compared to the US and EU-28, in particular, the domestic emission factor is relatively even and the spatial/temporal scale is not broken down sufficiently to reflect the domestic situation. As a way to improve the accuracy and expertise of estimating NH3 emission factors, a 'dynamic chamber-capture system' can be utilized, which allows complex considerations of compost, liquid manure, soil, and climate characteristics. By reviewing and comparing the data related to domestic and foreign NH3 emission, we identified shortcomings in the current domestic system and the directions to be taken and suggested a chamber system that could estimate NH3 emission flux. It is also necessary to establish a methodology for mesocosm systems in the field, in addition to indoor chamber systems, to be linked with practical policies, such as the calculation of new emission factors for missing sources.

Determination of the Optimum NH$_3$-N/NO$_2$-N Ratio by Anaerobic Batch Test in Anaerobic Ammonium Oxidation Process (혐기성 암모늄 산화공정에서 혐기성 회분식 실험에 의한 NH$_3$-N/NO$_2$-N의 최적비 산정)

  • Lee, Hwan-Hee;Kim, I-Jung;Jung, Jin-Young;Kim, Jee-Hyung
    • 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.