• 한국초지조사료학회지
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• 제37권1호
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• pp.56-60
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• 2017

Mineralization is an important biological process for conversion of organic nitrogen (N) to inorganic N which can be used by plants directly. To investigate the effect of different manures on soil mineralization, the soil amended with cattle (CtM), goat (GM), chicken manure (ChM) and pig slurry (PS) were incubated under in vitro condition and ammonium N ($NH_4{^+}-N$), ammonification rate and ammonia emission were determined for eighty-four days. $NH_4{^+}-N$ was the highest in PS-amended soil for the whole experimental period. $NH_4{^+}-N$ in PS-amended soil was gradually decreased until day 84, whereas it was rapidly decreased for the first 14 days and then slightly increased until 84 days in ChM-, CtM- and GM-amended soil. The ammonification rate showed negative value for the first 14 days in all treatments. From day 14, ammonification rate started to increase in CtM- and ChM-amended soil, whereas it was maintained in GM- and PS-amended soil until day 84. The daily ammonia emission was the highest in PS-amended soil ($41mg\;kg^{-1}d^{-1}$), followed by CtM-, ChM-, and GM-amended soil at day 1. It was gradually decreased until day 84 in all treatments. The total $NH_3$ emission was the highest in PS-amended soil with $0.6mg\;kg^{-1}$ for 84 days, while less than $0.1mg\;kg^{-1}$ in three other plots. These results indicate that different manures showed different soil ammonification rate and $NH_3$ emission.

• 아시안잔디학회지
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• 제5권1호
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• pp.47-53
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• 1991

A laboratory experiment was conducted in order to learn the effect of a number of organic matters on the ammonification and nitrification of urea, and the reaction of soil, applied to a loamy upland soil poor in orgnic matter(<1.5%, without plants 1.The ammonification of urea was most pronounced in one week period immediatly after fertilizer and water treated, after which a rapid decrease of it was followed showing no accumulation at the end of 3rd week. Owing to the accumlation of ammonium, pHs of treated soils were read 7.0 to 7.3 from 6.8~6.9. 2.Nitrification was also progressed rapidly in the first one week period so that the accumulation of NO$_3$-N surpassed that of ammonia during this period. After the 1st week the accumulation of N0$_3$-N was continuously increased showing the maximum at the end of 4 weeks following a sharp decrease at the end of 5th weeks. The accumulation of NO$_3$-N dropped soil pH from 6.8-7.0 to 6. 0-6.2,but the decrease of NO-N at the end of 5th weeks brought up soil pH to 6.4-6.6. again. 3.Amino acid fermentation byproduct rich in salt, paticularly chloride, slowed down the ammonification and nitrification of urea. 4.The application of organic matter diminished the acidifying effect of chemical fertilizers. The diminishing effect of soluble humic acid and amion acid fermentation byproduct showed greater than that of solid organic matter in this experiment, which might be own to the application of a rather small amount of water soluble organic matters. Rice straw powder among solid organic matters appeared to be the least in the diminishing effect above. It may be reasoned that these soluble organic matters decomposes rapidly so as to affect Soil pH, but solid organic matters, particularly the rice straw powder, form acidic humus.

• 상하수도학회지
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• 제14권2호
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• pp.196-206
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• 2000

Methanogenesis and denitrification in an upflow sludge baffled filter (UBF) reactor were studied using glucose as a fermentative substrate. Experiments were carried out to investigate how to reduce ammonification by changing alkalinity and $COD/NO_3-N$ ratio. Characteristics of granular sludges were examined by specifics methanogenic activity(SMA) and specific denitrification rate(SDR) tests. Microstructures of granules were examined using a scanning electron microscopy(SEM). It was found that COD was removed efficiently owing to the diverse microorganisms. In nitrate conversion, not only $COD/NO_3-N$ ratio but also influent alkalinity played important role in the ratio of denitrification and ammonification of nitrate. This reactor achieved over 95% COD and 99% nitrate removal efficiencies when influent contained 4000 mgCOD/L and $700mgNO_3-N/L$ at the hydraulic retention time of 24 hours. As $COD/NO_3-N$ ratio decreased, granular methanogenic activities using acetate and butyrate as substrates increased while activities using propionate and glucose decreased. There were three types in granules according to the surface color; gray, yellowish gray, and black. Gray or yellowish gray-colored granules were composed two layers, which were composed of black inner side and gray or yellowish gray surface substances. SEM illustrated that both were rod-type and cocci-type microorganisms resembling Methanothrix sp. and Methanococci sp. This study showed that by controlling the influent alkalinity and $COD/NO_3-N$ ratio, ammonification and denitrification could be manipulated.

• 한국재료학회지
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• 제23권2호
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• pp.104-111
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• 2013

In this study, GaN powders were synthesized from gallium oxide-hydroxide (GaOOH) through an ammonification process in an $NH_3$ flow with the variation of $B_2O_3$ additives within a temperature range of $300-1050^{\circ}C$. The additive effect of $B_2O_3$ on the hexagonal phase GaN powder synthesis route was examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transformation infrared transmission (FTIR) spectroscopy. With increasing the mol% of $B_2O_3$ additive in the GaOOH precursor powder, the transition temperature and the activation energy for GaN powder formation increased while the GaN synthesis limit-time ($t_c$) shortened. The XPS results showed that Boron compounds of $B_2O_3$ and BN coexisted in the synthesized GaN powders. From the FTIR spectra, we were able to confirm that the GaN powder consisted of an amorphous or cubic phase $B_2O_3$ due to bond formation between B and O and the amorphous phase BN due to B-N bonds. The GaN powder synthesized from GaOOH and $B_2O_3$ mixed powder by an ammonification route through ${\beta}-Ga_2O_3$ intermediate state. During the ammonification process, boron compounds of $B_2O_3$ and BN coated ${\beta}-Ga_2O_3$ and GaN particles limited further nitridation processes.

• Environmental Engineering Research
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• 제20권4호
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• pp.377-382
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• 2015

The high concentration of nitrogen and phosphorus in wastewater incorporated with the ability to use carbon dioxide as the carbon source make the microalgae become more attractive in wastewater treatment process. This study evaluates the optimal conditions for the digestion of settelable solids from the recirculating aquaculture system to produce the biomass of the green microalga Scenedesmus sp. After solids separation, aerobic digestion of settleable solids under disperse condition produced nitrate as the final product of consequently ammonification and nitrification processes. With the optimal digestion procedure, nitrate concentration during aerobic digestion in 2000 mL vessel increased from $9.63{\pm}0.65mg\;N/L$ to $58.66{\pm}0.06mg\;N/L$ in 10 days. Thereafter, cultivation of Scenedesmus sp. was performed in 1000 mL Duran bottle with air bubbling. The highest Scenedesmus sp. specific growth rate of $0.321{\pm}0.01/d$ was obtained in treatment using liquid fraction after aerobic digestion as the whole culture medium for Scenedesmus sp. cultivation. With this study, digestion of $8,800{\pm}128.12mg\;dry\;weight/L$ of settleable solids from fish pond finally produced $1,235{\pm}21mg\;dry\;weight/L$ of Scenedesmus sp. biomass.

• The Korean Journal of Ecology
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• 제18권4호
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• pp.493-502
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• 1995

Nodulation phenology in relation to plant phenology, vertical distribution of nodul and root biomass in different soil, correlation between nodule and root size, and nitrogen mineralization around the rhizosphere by ion-exchange resin bag buried at 10 cm of soil were studied in Elaeagnus nmbellata (autumn-olive) stand, Korea. Nodulation appeared from spring to autumn and nodule phenology was coincided with the timing of root activity rather than that of foliation. Nodul size increased in proportion to the root size. In the sand dune with the lower root biomass, nodule appeared up to 80 cm deep in soil and the nodule biomass was 1,070 kg/ha, which was the highest value reported for several actinorhizal plants in the temperate regions. It is suggested that nodule distribution and production are mainly influenced by soil aeration among environmental factors. The higher ammonification or lower nitrification rate contrasted markedly with the earlier studies that reported lower ammonification or higher nitrification in actinorhizal plant soil. Nitrogen mineralization rate around the rhizosphere with root and nodule was characterized by higher nitrification rate than that in the control soil without root and nodule.

• 생명과학회지
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• 제17권12호
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• pp.1682-1688
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• 2007

다기능성 농업용 미생물 제제를 개발하기 위하여 생물방제 및 생물비료 활성을 가지는 미생물을 탐색하였다. 본 연구실에서 분리 및 동정된 균주가운데 Pantoea agglomerans 및 Bacillus megaterium을 실험군주로 선정하였으며, 경남 밀양에 위치하는 양계장 부근 부엽토로부터 새로운 다목적 세균 MF12를 분리하였다. 형태학적, 배양적, 생화학적 특성 및 16S rDNA 염기서열을 분석한 결과, MF12는 Bacillus pumilis로 동정되었다. 이 균주들의 불용성 인산 가용능, IAA 및 siderophore 생성능, ammonification ability, 식물병원성 진균 세포성분 분해효소 생성능 및 항진균능을 조사하였다. P. agglomerans는 고체배지에서 불용성 인산을 가용화할 수 없었으나 액체배지에서는 가용성 인산을 생성하였다. 상기 모든 균주들은 배양시간에 따라 $3{\sim}639{\mu}g/ml$의 IAA를 생성하였으며, P. agglomerans만이 siderophore를 생성하였다. 이 균주는 pectinase와 lipase를 생성하였다. B. megaterium은 amylase, pretense 및 lipase를 생성한 반면 B. pumilisr는 protease와 lipase를 생성하였다. P. agglomerans는 Fusarium oxysporum과 Colletotrichum gloeosporioides의 생육을 억제하였으며, B. pumilis는 Botrytis cinerea, Sclerotinia sclerotiorum 및 Phythium ultimum의 생육을 억제하였다.

• 한국토양비료학회지
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• 제23권4호
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• pp.293-296
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• 1990

규회석분말, 염화칼륨, 황산칼륨이 요소의 암모니아화 및 질산화에 주는 영향을 밝히고자 흙 500g씩을 플라스틱 포트에 담아 비닐하우스내($30{\sim}35^{\circ}C$)에서 17일간 밭상태로 보존하며 얻은 시험 결과는 다음과 같다. 1. 황산칼리는 염화칼리보다 규회석분말의 토양산성중화를 용이하게 하였으며 이 효과가 요소질소의 암모니아화 및 질산화를 촉진하였다. 2. pH 6.0이하에서는 $(NH_4+NO_3)-N$에 대한 $NO_3-N$의 비율이 20%이다. 3. 토양의 pH 5.2~6.0은 암모니아의 질산화를 억제하는 임계범위가 되거나, 질산화를 억제하는 농도까지 암모니아를 집적시키기 쉬운 범위인 것 같다. 4. 암모니아의 질산화는 저수분의 풍건토양에서도 일어나는 것 같다.

• 한국토양비료학회지
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• 제15권3호
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• pp.166-171
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• 1982

석회물질(石灰物質)과 볏짚의 시용(施用)이 암모니아 휘산(揮散)에 주는 영향(影響)을 밝히기 위하여 요소(尿素)를 시용(施用)한 담수토양(湛水土壤)을 34일간(日間) $30{\sim}35^{\circ}C$에서 (보관(保管)) 질내시험결과(窒內試驗結果)는 아래와 같다. 1. 수산화(水酸化)칼슘과 규산(珪酸)칼슘은 중탄산염 만들어 담수토양(湛水土壤)의 pH를 높이고 암모니아의 휘산량(揮散量)을 증가시켰고 담수토양(湛水土壤)의 수충능(綬衝能)을 크게 하는 효과가 컸다. 2. 볏짚분(粉)의 시용(施用)은 탄산(炭酸)을 집적(集積)시켜 담수토양(湛水土壤)의 pH를 낮추고 암모니아의 휘산(揮散)을 줄였는데 그 효과는 석회(石灰)를 시용(施用)하지 않았을 때에 컸다. 3. 수산화(水酸化)칼슘은 담수초(湛水初) $CO_2$의 발생을 억제(抑制)했는데 규산(珪酸)칼슘은 토양(土壤)에 수(綬)한 변화를 주어 담수초(湛水初)부터 토양질소(土壤窒素)의 유효화(有效化)를 촉진(促進)하고 볏짚의 시용(施用)도 이런 토양조건을 빨리 조성(造成)하는 것으로 판단되였다.

• 상하수도학회지
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• 제13권4호
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• pp.35-44
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• 1999

In this study, it was attempted to remove nitrate and carbon in a single-stage reactor using acetate as substrate. Hybrid type upflow sludge baffled filter reactor was adopted using anaerobic sludge. Sludge bed in the bottom of reactor was intended to remove carbon and nitrate by denitrification and methanogenesis. And floating media in the upper part of reactor were intended to remove remaining carbon which was not removed due to the inhibition of nitrogen oxide on methane producing bacteria. The reactor removed over 96% of COD and most of nitrate with volumetric loading rate of $4.0kgCOD/m^3{\cdot}day$, hydraulic retention time of 24hr, 4,000mgCOD/L, and $266mgNO_3-N/L$. Nitrate in anaerobic sludge was converted to nitrogen gas(denitrification) or ammonia (ammonification) according to pH of influent, COD removal efficiency was easily affected by the change of volumetric loading rates and nitrate concentration. And when influent pH was about 4.7, most nitrate changed to ammonia while when influent pH was about 6.8~7.0, most nitrate denitrified independent of $COD/NO_3-N$ ratio. Most granules were gray and a few were black. In gray-colored granule, black inner side was covered with gray substance and SEM illustrated Methanoccoci type microorganisms which were compact spherical shape. Anaerobic filter removed residual COD effectively which was left in sludge bed due to the inhibition of nitrogen oxide.