• 한국초지조사료학회지
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• 제36권3호
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• pp.199-204
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• 2016

The objective of this study was to determine the effect of nitrification inhibitor dicyandiamide (DCD) and urease inhibitor hydroquinone (HQ) on ammonia ($NH_3$) and nitrous oxide ($N_2O$) emission from pig slurry applied to Timothy (Phleum pretense L.) sward. The daily emission of ammonia ($NH_3$) and nitrous oxide ($N_2O$) was monitored for 9 days in three different treatments; 1) control (only pig slurry application), 2) DCD treatment (pig slurry + DCD), and 3) HQ treatment (pig slurry + HQ). Most $NH_3$ emission occurred after 4~5 days in three treatments. Total $NH_3$ emission, expressed as a cumulative amount throughout the measurement time, was $1.33kg\;N\;ha^{-1}$ in the control. The DCD and HQ treatment decreased total $NH_3$ emission by 16.3% and 25.1%, respectively, compared to the control. Total $N_2O$ emission in the control was $47.1g\;N\;ha^{-1}$. The DCD and HQ treatment resulted in a reduction of 67.9% and 41.8% in total $N_2O$ emission, respectively, compared to the control. The present study clearly indicated that nitrification and urease inhibitor exhibited positive roles in reducing N losses through $NH_3$ and $N_2O$ emission.

• 공업화학
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• 제18권3호
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• pp.255-261
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• 2007

망간계 금속산화물을 이용한 저온 선택적 촉매 환원 반응에 대하여 연구하였다. 망간계 금속산화물은 $200^{\circ}C$ 이하의 저온에서 우수한 탈질 특성을 보인다. 온도에 따른 $NH_3/NOx$ 몰비 변화 실험을 통하여 미반응 암모니아의 배출은 몰비가 증가하고 온도가 감소할수록 증가하였으며, $NO_2$의 발생은 반대의 현상을 보였다. $NO_2$는 NO가 촉매 표면에 흡착된 후 nitrate종으로 산화되어 생성되는 것으로 보인다. 촉매 표면에 생성된 nitrate종과 흡착된 암모니아가 반응하기 때문에 $NH_3/NOx$ 몰비 1.0 이상에서도 미반응 암모니아의 배출이 없었다. 담지된 금속산화물의 영향은 Zr은 산화상태를 증가시켜 $NO_2$의 배출이 증가하였으며, Ce를 첨가시킨 경우 $NO_2$ 발생량이 감소하였다. 그러나 금속산화물의 첨가는 전체적으로 NOx 전환율을 감소시켰다

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.786-794
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• 2022

Green ammonia is a promising renewable energy carrier. Green ammonia can be used in various energy conversion devices (e.g., engine, fuel cell, etc.). Ammonia has to be fed with hydrogen for start-up and failure protection of some energy conversion devices. Ammonia can be converted into hydrogen by decomposition and partial oxidation. Especially, partial oxidation has the advantages of fast start-up, thermally self-sustaining operation and compact size. In this paper, thermodynamics, start-up and operation characteristics of ammonia partial oxidation were investigated. O₂/NH₃ ratio, ammonia flow rate and catalyst volume were varied as operation parameters. In thermodynamic analysis, ammonia conversion was maximized in the O₂/NH₃ range from 0.10 to 0.15. Ammonia partial oxidation reactor was successfully started using 12 V glow plug. At 0.13 of O₂/HN₃ ratio and 10 LPM of ammonia flow rate, ammonia partial oxidation reactor showed 90% of ammonia conversion over commercial Ru catalyst. In addition, Increasing O₂/NH₃ ratio from 0.10 to 0.13 was more effective for high ammonia conversion than increasing catalyst volume at 0.10 of O₂/NH₃.

• 한국초지조사료학회지
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• 제44권2호
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• pp.133-139
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• 2024

This study aimed to evaluate the efficiency of combining acidification with adsorbents (zeolite and biochar) to mitigate the environmental impacts of pig slurry, focusing on ammonia (NH₃) emission and nitrate (NO₃^-) leaching. The four treatments were applied: 1) pig slurry (PS) alone as a control, 2) acidified PS (AP), 3) acidified pig slurry with zeolite (APZ), and 4) acidified pig slurry with biochar (APB). The AP mitigates NH₃ emission and NO₃^- leaching compared to PS alone. Acidification reduced the cumulative NH₃ emission and its emission factor by 35.9% and 12.5%, respectively. The APZ and APB increased NH₄⁺-N concentration, with the highest level in APB, compared to AP. The NH₄⁺ adsorption capacity of APB (0.90 mg g^-1) was higher than that of APZ (0.63 mg g^-1). The APB and APZ treatments induced less NH₃ emission compared to AP. The cumulative NH₃ emission was reduced by 12.2% and 27.6% in APZ and APB, respectively, compared to AP treatment. NO₃^- leaching began to appear on days 12 and 13, and its peak reached on days 16 and 17, which were later than AP. The cumulative NO₃^- leaching decreased by 17.7% and 25.0% in APZ and APB, respectively, compared to AP treatment. These results suggest that combining biochar or zeolite with acidified pig slurry is an effective method to mitigate NH₃ emission and NO₃^- leaching, with biochar being particularly effective.

• 한국산업융합학회 논문집
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• 제26권6_2호
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• pp.1171-1181
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• 2023

In this study, a sweep gas - vacuum hybrid type membrane degassing process was proposed for ammonia wastewater treatment. In addition, the ammonia selective recovery of the hybrid type membrane degassing process was also investigated. As a result, the hybrid type membrane degassing process showed better degassing performance (54.9 mg NH₃/m²min for 360 min) than the sweep gas type (32.3 mg NH₃/m²min) or vacuum type (22 mg NH₃/m²min). Additionally, the hybrid type membrane degassing process showed an excellent ammonia selectivity (103 times compared to Na+ Na⁺, 133 times compared to Ca²⁺). The ammonia selectivity was appeared to be due to the conversion characteristics of ammonium ion / dissolved ammonia depending on pH. The results in this study are expected to be used in the development of ammonia wastewater treatment and ammonia recovery in the future.

• 한국양식학회지
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• 제10권4호
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• pp.435-438
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• 1997

전기분해를 이용한 해수의 암모니아성 질소 및 대장균 제거에 효과적이었다. 암모니아의 제거효율은 전류의 세기가 클수록, 반응 시간이 길수록, 극판간격이 좁을수록 증가하였다. 해수내 250/100 m\ell$의 대장균은 모든 실험 조건에서 검출되지 않아, 살균 목적으로 전기분해가 매우 효과적이었다. 암모니아의 제거 효율은 잔류 염소의 농도에 따라 증가하였다. 암모니아의 제거 효율과 잔류 염소와의 관계는 다음과 같다.$NH_4^+-N(%)=4cdotlog[Residual\;chlorine(mg/\ell)+28(r=0.892)$

• 유기물자원화
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• 제17권1호
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• pp.49-57
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• 2009

본 연구에서는 UASB 반응조를 이용한 슬러리형 돈사폐수의 혐기성 소화시 암모니아 부하의 영향을 평가하였다. UASB 반응조는 $0.02{\sim}0.96kg{NH_4}^+-N/m^3/day$ 범위의 NVLR로 운전되었으며, 정상상태에서 biogas내 메탄함량은 73.3~77.9%였다. FA 농도는 메탄생성미생물의 저해 범위까지 증가하였으나, 메탄함량을 고려할 때, FA와 TA로 인한 저해는 발생하지 않았다. NVLR이 증가함에 따라 COD 제거율은 악화되었으며, $0.55kg{NH_4}^+-N/m^3/day$ 이하의 부하에서 COD 제거율을 60% 이상으로 유지할 수 있었다. NVLR이 0.09에서 $0.96kg{NH_4}^+-N/m^3/day$로 증가함에 따라, biogas의 생성량은 3.71에서 9.14L/day로 증가하였으며, COD의 메탄으로 전환율은 0.32에서 $0.20m^3CH_4/kg$으로 감소하였다. FA농도, COD 제거율, 메탄생성률 등을 고려할 때, UASB 반응조는$0.40kg{NH_4}^+-N/m^3/day$ 이하의 NVLR로 운영되어야 한다.

• 한국분무공학회지
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• 제25권4호
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• pp.196-203
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• 2020

Nowadays, urea SCR technology is considered as the most effective NOx reduction technology of diesel engine. However, low NOx conversion efficiency under low temperature conditions is one of its problems to be solved. This is because injection of UWS (Urea Water Solution) is impossible under such a low temperature condition due to the problem of insufficient of urea decomposition and urea deposits. In several previous studies, it has been reported that appropriate control of the amount of ammonia adsorbed on SCR catalyst can improve the NOx conversion efficiency under low temperature conditions. In this study, we tried to find out how much the NOx conversion efficiency increases with respect to the amount of ammonia adsorbed on the catalyst, and what the temperature conditions that the ammonia slip occurs. This study shows the results of 8 times repeated WHTC test with a diesel engine, in which UWS was injected with NH3/NOx mole ratio of '1'. Through this study, it was found that 13% of the NOx conversion efficiency of WHTC increased while the θ (ammonia adsorption rate) increased from "0%" to "22%". In addition, it is found that in cases of high θ value, the significant improvement of NOx conversion efficiency at low temperatures presented during the beginning period of WHTC and at high temperature and transient conditions presented during last part of WHTC test. The NH3 slip occurring condition was 250℃ of catalyst temperature and 10% of θ, and the amount of NH3 slip increased as the temperature and θ are increased.

• 한국어류학회지
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• 제29권1호
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• pp.13-21
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• 2017

본 연구는 능성어(Epinephelus septemfasciatus)를 해수 순환여과양식시스템(RAS)에 적용하는데 문제가 되는 암모니아의 농도 기준을 제시하기 위하여 96시간 동안 암모니아 노출에 따른 생존율 및 혈액학적 특성 변화를 조사하였다. 생존율 실험구의 암모니아 농도는 대조구, 0.35, 0.4, 0.5, 0.8 mg/L였으며, 96-h $LC_{50}$ 농도는 0.6 mg/L로 나타났다. 능성어 치어의 암모니아 96-h $LC_{50}$ 농도인 0.6 mg/L에서 0, 3, 6, 12, 24, 48, 72, 96시간 간격으로 12마리씩 혈액 샘플링을 하였다. 실험구의 암모니아 노출 시간이 경과할수록 혈장 코티졸, 글루코스, GOT 및 GPT 농도가 증가하는 경향을 보였다. 혈장 암모니아와 총 단백질은 암모니아 노출 12시간째까지는 증가하였고 이후로는 감소하였지만, 대조구와 비교하여 유의하게 높은 값을 나타내었다. 또한 혈장 전해질이온($Na^+$, $Cl^-$)과 삼투압은 감소하는 경향이 관찰되었다.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.306-311
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• 1992

The stable structures of pure ethylene and mixed ethylene-ammonia cluster ions are studied using an electron impact ionization time-of-flight mass spectrometer. Investigations on the relative cluster ion distributions of $(C_2H_4)_n(NH_3)_m^+$ under various experimental conditions suggest that $(C_2H_4)_2(NH_3)_3^+$ and $(C_2H_4)_3(NH_3)_2^+$ ions have the enhanced structural stabilities, which give insight into the feasible structure of solvated ions. For the stable configurations of these ionic species, we report an experimental evidence that both $(C_2H4)_2^+(C_2H_4)_3^+$ clusters as the central cations provide three and two hydrogen-bonding sites, respectively, for the surrounding $NH_3$ molecules. This interpretation is based on the structural stability for ethylene clusters and the intracluster ion-molecular rearrangement of the complex ion under the presence of ammonia solvent molecules.