• 한국환경농학회지
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• 제40권3호
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• pp.161-168
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• 2021

BACKGROUND: Biochar has ability to reduce N loss, increase crop yield, and sequestrate carbon in the soil However, there is still limited study concerning the interactive effects of various biochars on NH₃ loss and plant growth. This study, therefore, was conducted to investigate the NH₄⁺ adsorption characteristics of biochar derived from rice and maize residues. METHODS AND RESULTS: By-products were pyrolyzed under oxygen-limited conditions at 300-700℃ for 1 hour and used for experiment of NH₄⁺ adsorption in aqueous solution. The adsorption characteristics of biochar were studied using Langmuir isotherm. Biochar yield and hydrogen content decreased with increasing pyrolysis temperatures, whereas pH, EC, and total carbon content increased. The biochar pyrolyzed at lower temperatures was more efficient at NH₄⁺ adsorption than those produced at higher temperatures. In addition, the R_L values, indicating equilibrium coefficient were between 0 and 1, confirming that the result was suitable for Langmuir isotherm. CONCLUSION: The maize stalk biochar pyrolyzed at 300℃ was the most efficient to adsorb NH₄⁺ from the aqueous solution. Furthermore, the adsorption results of this experiment were lower than those of other prior studies, which were ascribed to different experimental conditions such as ingredients, and pyrolysis conditions.

• 방사선산업학회지
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• 제4권4호
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• pp.313-317
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• 2010

The struvite crystallization was applied to remove $NH_4{^+}$ in livestock wastewater. The ammonium ions can be very toxic to the aquatic creatures. In this experiments, the livestock wastewater from Gongju livestock wastewater treatment plant was used. The behaviors of various parameters such as pH, mole ratio of $Mg^{2+}$ : $NH_4{^+}$ : $PO{_4}^{3-}$ and reaction temperature for struvite crystallization of livestock wastewater and the effect of gamma ray irradiation were evaluated. As results, for the pH variation, the $NH_4{^+}$ removal efficiency showed the highest, 88%, at pH 9~9.25. The removal efficiency of $NH_4{^+}$, $Mg^{2+}$ and $PO{_4}^{3-}$ was showed highest when same molar ratio of $Mg^{2+}$ and $PO{_4}^{3-}$ were applied. The $NH_4{^+}$ removal efficiency showed 82% at $7^{\circ}C$, and 90% at $30^{\circ}C$ with temperature. When the wastewater was irradiated with 20 kGy of gamma ray, $NH_4{^+}$ was removed as much as 83%.

• 한국미생물·생명공학회지
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• 제2권2호
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• pp.79-82
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• 1974

볏짚 등 농산폐자원을 섬유소자화세균의 기질로 사용하여 섬유소단세포단백을 생산할 때 섬유소의 분해성을 높이기 위해 각종 알카리에 의한 전처리의 효과를 살펴 본 결과 NaOH가 가장 좋은 전체 처리제 이었으며 NH$_4$OH는 NaOH 보다 처리 효과는 낮으나 염가로 구입할 수 있고 처리 후 중화하여 미생물의 질소원으로 사용할 수 있어 경제적인 처리제로 나타났다. NH$_4$OH를 처리제로 사용할 경우 1규정 농도 이상의 용액으로 처리하거나 가열하여도 처리 효과가 증가하지않았다. 1규정농도의 NH$_4$OH로 처리한 후 황산으로 중화하여 생성된 5.3%의 (NH$_4$)$_2$SO$_4$는 분리한 Cellulomonas속 세균의 생육을 저해하지않았으며 세척으로 유실되는 유기물이 이용되는 것으로 나타났다. 1규정농도의 NH$_4$OH로 처리한 벗짚의 분리균 Cellulomonas aurogena 및 C. flavigena에 의한 분해율은 기질농도4%일 때 46%이었으며 이때 6.3~6.45g/1의 균체를 생산하였다.

• 전기화학회지
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• 제16권3호
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• pp.123-128
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• 2013

유기물 첨가에 따른 CDI 모듈셀의 N, P 제거 특성을 위해 2000 ppm $NH_3$, $H_3PO_4$에 methanol, ethanol, iso-propanol, methoxy ethanol, glucose을 1, 2, 3 vol.%를 첨가해 용량 및 이온의 흡 탈착능을 관찰하였다. $NH_3$에서는 탄소수가 증가할수록 용량은 감소하는 경향을 나타내었으며, 용량은 methanol 3 vol.% 첨가 될 때 유기탄소 간섭 전보다 흡착은 16.4%, 탈착은 30.4%의 질소 제거율 증가를 나타내었다. $H_3PO_4$에서는 iso-propanol 2 vol.% 첨가 시에 유기탄소 간섭 전보다 흡착은 63%, 탈착은 54.7% 인산염의 제거율 증가를 확인하였다. 따라서 본 연구에서는 폐수 내의 유기물을 제거하지 않고 N, P 제거 효과와 운영비용을 감소할 수 있는 결과를 나타내었다.

• 대한화학회지
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• 제37권7호
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• pp.662-671
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• 1993

isonitrosomethylacetoacetate(H-IMAA)의 이민유도체를 리간드로하는 새로운 Ni(II) 및 Pd(II)착물, Ni(IMAA-NH)(IMAA-NH'), Ni(IMAA-NH)(IMAA-NR),$ Pd(IMAA-NH)_2$, 및 $Pd(IMAA-NR)_2(R=CH_3,\;n-C_3H_7,\;n-C_4H_9$, 또는 $CH_2C_6H_5)$을 합성하고, 이들 착물의 구조를 원소분석, 전자흡수분광법, 적외선흡수분광법, $^1H$ 및 $^{13}C$ 핵자기공명분광법으로 조사하였다. 여기서 H-IMAA-MH 및 H-IMAA-NR은 각각 isonitrosomethylacetoacetate imine 및 N-alkylisonitrosomethylacetoacetate imine 유도체를 나타낸다.

• 공업화학
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• 제22권3호
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• pp.255-260
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• 2011

$K^{+}-{\beta}^{{\prime}{\prime}}$-alumina pellet를 이온교환 매체인 ammonium nitrate 수용액과 용융염으로 각각 이온교환하여, 고온형 PEMFC 전해질로 기대되는 무기소재인 $NH_4{^+}-{\beta}^{{\prime}{\prime}}$-alumina를 제조하였다. 고압반응기의 실험조건으로 온도는 130, 150, 170, $200^{\circ}C$ 에서, 시간은 2 h 간격으로 2 h에서 8 h까지 수열반응을 실시하였으며 이 때의 수용액의 농도는 5 M과 10 M을 사용하였다. 또한 $200^{\circ}C$의 가열기 위에서 ammonium nitrate를 완전히 녹여 용융염 상태의 ammonium nitrate를 이용하여 2 h 간격으로 2 h에서 8 h까지 이온교환을 실시하였다. 이온교환반응의 반복횟수에 따른 영향을 알아보기 위하여 재이온교환반응을 3차까지 반복해서 실험하였다. 이후 이온교환 된 $NH_4{^+}-{\beta}^{{\prime}{\prime}}$-alumina 구조체의 상 안정성, 이온교환율을 각각 X선 회절기(Rigaku Rint 2000, Japan)와 ICP-AES (Spectro, Modular EOP)를 사용하여 분석하였다.

• Rapid Communication in Photoscience
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• 제4권4호
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• pp.79-81
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• 2015

The influence of the grain size of the $CH_3NH_3PbI_3$ on the solar cell performance is investigated by controlling the ratio between $CH_3NH_3I$ and $PbI_2$ precursors. As the concentration of the precursors increased from 1.0M to 2.0M, the $CH_3NH_3PbI_3$ grain size increased from ~100nm to ~400nm. The solar cell utilizing the $CH_3NH_3PbI_3$ with large grain size shows improved photocurrent compared to the solar cell utilizing $CH_3NH_3PbI_3$ with small grain size, which is ascribed to the reduced recombination at the boundaries of grains.

• 한국응용곤충학회지
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• 제8권
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• pp.19-23
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• 1969

질소원, 탄소원을 달리하여 배양한 Fusarium oxysporium f. cucumerinum에 Grand 유제를 농도별로 처리했을 때 균사의 발육신장에 미치는 영향에 대하여 비교 검토한 실험결과를 보면 다음과 같다. (1) Fusarium oxysporium f. cucumerinum은 질소원이 $(MH_4)_2HPO_4,\; NH_4NO_3$인 배지에서 탄소원은 Fructose 배지에서 균사의 발육신장이 양호하였다. (2) 각종 질소원과 탄소원에서 배양한 균을 Grand유각 1,000배액을 처리하면 다같이 균사의 발육이 완전히 조지되었으며 5,000배액에서는 영양원의 종류에 따라 차이가 있어 $NH_4NO_3$배지, Lactose배지, Fructose 배지에서 배양한 균만 생육이 조지되고 기타 영양원에서 배양한 균은 균사의 신장은 되었으나 무처리에 비해 어느정도 억제되는것 같다. 10,000배액에서는 모든 종류의 영양원에서 배양한 균이 균사의 신장이 일어났는데 무처리에 비해 생육이 촉진되는 것도 있고 $NH_4NO_3$ 배지, Fructose배지에서 배양한 균은 오히려 억제되는 것도 있었다. (3) 이상 연구결과로 보아 Grand유제는 농도와 오이 만할병균이 영양상태에 따라 살균력에 영향을 주는것으로 사려된다.

• 농업과학연구
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• 제47권4호
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• pp.1049-1056
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• 2020

Ultrafine dust causes asthma and respiratory and cardiovascular diseases when inhaled. Ammonia (NH3) plays a big role in ultrafine dust formation in the atmosphere by reacting with nitrogen oxides (NOx) and sulfur oxides (SOx) emitted from various sources. The agricultural sector is the single largest contributor of NH3, with the vast majority of emissions ensuing from fertilizers and livestock sector. Interest in using biochar to attenuate these NH3 emissions has grown. This experiment was conducted to study the effects of using rice hull biochar pyrolyzed at three different temperatures of 250℃ (BP 4.6, biochar pH 4.6), 350℃ (BP 6.8), and 450℃ (BP 10.3) on the emission of ammonia from soil fertilized with urea. The emissions of NH3 initially increased as the experiment progressed but decreased after peaking at the 84th hour. The amount of emitted NH3 was lower in soil with biochar amendments than in that without biochar. Emissions amongst biochar-amended soils were lowest for the BP 6.8 treatment, followed in an ascending order by BP 10.3 and BP 4.6. Since BP 6.8 biochar with neutral pH resulted in the lowest amount of NH3 emitted, it can be concluded that biochar's pH has an effect on the emissions of NH3. The results of this study, therefore, indicate that biochar can abate NH3 emissions and that a neutral pH biochar is more effective at reducing gaseous emissions than either alkaline or acidic biochar.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.661-672
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• 1998

Two experiments were conducted to examine the effects of a range of concentrations of ruminal fluid ammonia ($NH_3$-N) on forage digestibility, microbial growth efficiency and the mix of microbial species. Urea was either continuously infused directly into the rumen of sheep fed 33.3 glh of oaten chaff (Exp. I) or sprayed onto the oaten chaff (750 g/d) given once daily (Exp. 2). Concentrations of $NH_3$-N increased with incremental addition of urea (p < 0.01). Volatile fatty acids (VFA) concentrations and 24 h in sacco organic matter digestibility in the rumen were higher when supplemental urea was given (p < 0.01). The (C2 + C4) : C3 VFA ratio was lower (p < 0.05) when $NH_3$-N was above 200 mgN/I. The fungal sporangia appearing on oat leaf blades were significantly higher when urea was supplemented, indicating that $NH_3$-N was a growthlimiting nutrient for fungi at levels of $NH_3$-N below 30 mgN/l. The density of protozoa was highest when $NH_3$-N concentrations were adjusted to 30 mgN/I for continuously fed ($4.4{\times}10^5/ml$) and to 168 mgN/1 for once daily feeding ($2.9{\times}10^5/ml$). Thereafter increasing concentrations of $NH_3$-N, were associated with a concomitant decline in protozoal densities. At the concentration of $NH_3$-N above 200 mgN/l, the density of protozoa was similar to the density of protozoa in ruminal fluid of the control sheep ($1.8{\times}10^5/ml$). The efficiency of net microbial protein synthesis in the rumen calculated from purine excretion was 17-47% higher when the level of $NH_3$-N was above 200 mgN/1. The possibilities are that 1) there is less bacterial cell lysis in the rumen because of the concomitant decrease in the protozoal pool and/or 2) microbial growth per se in the rumen is more efficient with increasing $NH_3$-N concentrations.